198: Phototherapy Flashcards
What are the main types of phototherapeutic devices used in phototherapy?
The main phototherapeutic devices include Broadband UVB (BB-UVB), Narrowband UVB (NB-UVB), Ultraviolet A (UVA), and Psoralen photochemotherapy (PUVA).
How does UVB radiation affect the skin and immune system?
UVB radiation (290 to 320 nm) is absorbed by the epidermis and superficial dermis, produces DNA damage, mediates UVB-induced immunosuppression, increases hydroxyvitamin D synthesis, and affects signal transduction pathways.
What is the significance of reactive oxygen species (ROS) in UVA radiation exposure?
UVA radiation (320 to 400 nm) generates ROS, which exceed neutralization by protective activities, are implicated in photoaging and skin cancer, and have immunoprotective properties in animal studies.
What are the effects of psoralen photochemotherapy on DNA?
Psoralen photochemotherapy intercalates with DNA upon UVA activation, forming adducts that crosslink DNA strands, inducing DNA damage and reactive oxygen intermediates.
How does phototherapy influence the immune system?
Phototherapy generates effector and regulatory T cells, with the immune response intensity dependent on their proportions, and can lead to immunosuppression.
What are the main phototherapeutic devices used in phototherapy and their respective wavelengths?
The main phototherapeutic devices and their wavelengths are: Broadband UVB (290 to 320 nm), Narrowband UVB (310 to 315 nm), UVA (320 to 400 nm), and PUVA (UVA range with psoralen activation).
How does UVB radiation affect the skin and what types of DNA damage does it produce?
UVB radiation affects the skin by being absorbed superficially and producing DNA damage, including pyrimidine dimers and 6,4-pyrimidine-pyrimidone photoproducts.
What is the significance of reactive oxygen species (ROS) generated during UVA radiation exposure?
ROS generated during UVA exposure are significant as they contribute to photoaging and skin cancer and exceed the neutralization capacity of protective activities.
What role does psoralen play in photochemotherapy and how does it interact with DNA?
Psoralen intercalates with DNA when activated by UVA, forming adducts that crosslink DNA strands, leading to DNA damage.
How does UVB radiation influence vitamin D production in the skin?
UVB radiation increases hydroxyvitamin D synthesis, inversely correlating with trans-urocanic acid levels.
What are the immune system effects of phototherapy under normal circumstances?
Phototherapy generates both effector and regulatory T cells, with the immune response intensity dependent on their relative proportions.
What are the clinical implications of the different depths of penetration of UVB and UVA radiation?
UVB primarily affects the epidermis and superficial dermis, while UVA penetrates deeper, reaching the mid-dermis.
What are the potential side effects of phototherapy related to UV radiation exposure?
Potential side effects include short-term sunburn-like reactions, long-term skin cancer risks, and possible immunosuppression.
How does the generation of reactive oxygen intermediates during phototherapy relate to skin damage?
Reactive oxygen intermediates cause oxidative stress, leading to DNA damage and contributing to photoaging and skin cancer.
What is the relationship between UVA radiation and the production of heme oxygenase-1 in animal studies?
UVA radiation induces heme oxygenase-1 production, which has immunoprotective, antioxidant, and anti-inflammatory effects.
What is the effect of UVB exposure on effector and regulatory T cells?
UVB exposure inhibits effector T cell activation while leaving regulatory T cells unaltered, diminishing cell-mediated immune response.
How does UVA1 affect mast cells compared to PUVA?
UVA1 causes apoptosis of mast cells, reducing their concentrations, while PUVA stabilizes mast cell membranes.
What are the effects of phototherapy on collagen production?
Phototherapy activates MMP-1 and increases IL-1 and IL-6 production, enhancing collagen remodeling.
What changes occur in keratinocytes due to UVB, PUVA, and UVA exposure?
These exposures cause acanthosis of the epidermis and thickening of the stratum corneum.
What role does interleukin-10 (IL-10) play in the immune response following UV exposure?
Increased IL-10 levels serve as an immunosuppressive factor, diminishing dendritic cell antigen presentation.
What is the effect of UVB exposure on the activation of effector T cells and regulatory T cells?
UVB exposure inhibits effector T cell activation while leaving regulatory T cells unaltered.
How does UVB exposure affect dendritic cells and their role in T cell responses?
UVB exposure disrupts dendritic cell activities, diminishing their capacity to present antigens.
What are the immunosuppressive soluble mediators that increase following UVB exposure?
Following UVB exposure, mediators such as platelet activating factor receptor agonists, MSH, CGRP, and IL-10 increase.
What is the role of Prostaglandin E2 in the context of UVB exposure?
Prostaglandin E2 acts as an inductive stimulus for cyclooxygenase-2, which is lowered by UV exposure.
What are the effects of PUVA on mast cells?
PUVA stabilizes mast cell membranes and limits histamine release.
How does UVA1 exposure affect mast cells compared to PUVA?
UVA1 exposure leads to mast cell apoptosis, reducing their concentrations, unlike PUVA.
What is the impact of phototherapy on collagen production?
Phototherapy activates MMPs, affecting collagen metabolism.
How does phototherapy treatment affect keratinocytes in terms of epidermal thickness?
Phototherapy causes acanthosis of the epidermis and thickening of the stratum corneum.
What is the clinical significance of increased keratinocyte CD54 expression due to phototherapy?
Increased CD54 expression facilitates T-cell binding, enhancing phototherapy efficacy in inflammatory conditions.
What adjustments must be made to phototherapy treatment doses due to the effects on the epidermis?
Treatment doses must be progressively increased to reach therapeutic targets in the lower epidermis and dermis.
What is the relationship between UV exposure and the levels of immunomodulatory factors?
UV exposure significantly lowers levels of immunomodulatory factors like prostaglandin D2.
How does UVA1 influence the expression of intercellular adhesion molecule-1 (ICAM-1) in keratinocytes?
UVA1 exposure induces ICAM-1 expression in keratinocytes, facilitating T-cell binding.
What is the effect of phototherapy on the apoptosis of T cells in cutaneous lymphoid infiltrates?
Phototherapy causes apoptosis of T cells in cutaneous lymphoid infiltrates.
What is the significance of FoxP3-positive regulatory T cells in the context of UVB exposure?
FoxP3-positive regulatory T cells can convert into IL-17-producing cells following UVB exposure.
What are the potential therapeutic implications of the effects of PUVA on mast cells?
PUVA stabilization of mast cells may limit histamine release, beneficial for managing allergic responses.
How does phototherapy contribute to the management of chronic photosensitivity disorders?
Phototherapy can harden the skin, allowing greater sun exposure tolerance.
What is the role of IL-4 in the acute skin lesions of atopic dermatitis following UVA1 exposure?
UVA1 exposure increases IL-4 expression, associated with the inflammatory response in atopic dermatitis.
What is the effect of UVB on the balance of effector and regulatory T cells?
UVB exposure biases the equilibrium toward a diminished cell-mediated immune response.
What is the significance of the increased levels of IL-10 following UV exposure?
Increased IL-10 levels indicate an immunosuppressive effect influencing the skin’s immune response.
How does phototherapy affect the production of matrix metalloproteinases (MMPs)?
Phototherapy increases MMP production, involved in collagen and extracellular matrix remodeling.
What is the relationship between UVA radiation and the production of inflammatory cytokines?
UVA radiation increases inflammatory cytokines IL-1 and IL-6, stimulating MMPs and contributing to skin inflammation.
What are the implications of the effects of UVB, PUVA, and UVA on keratinocyte function?
These forms of phototherapy can lead to keratinocyte acanthosis and thickening of the stratum corneum.
What is the impact of UV exposure on the expression of adhesion molecules in the skin?
UV exposure can induce adhesion molecules like CD54 in keratinocytes.
How does the effect of PUVA on mast cells differ from that of UVA1?
PUVA stabilizes mast cell membranes, while UVA1 causes apoptosis of mast cells.
What is the clinical relevance of the effects of phototherapy on collagen metabolism?
MMP activation by phototherapy aids in treating sclerotic skin diseases.
What changes occur in the levels of immunomodulatory factors due to UV exposure?
UV exposure leads to a decrease in immunomodulatory factors such as prostaglandin D2.
What is the significance of the interaction between T cells and keratinocytes facilitated by ICAM-1?
This interaction is significant for immune responses in the skin, particularly in inflammatory conditions.
How does phototherapy affect the overall immune response in the skin?
Phototherapy modulates the immune response by affecting T cell activation, dendritic cell function, and cytokine production.
What are the potential benefits of increased keratinocyte CD54 expression due to phototherapy?
Increased CD54 expression may enhance phototherapy efficacy in treating inflammatory skin diseases.
What is the effect of UVB on the production of interleukin-10 and its implications?
UVB exposure increases interleukin-10 production, which has immunosuppressive effects.
What is the role of amphiregulin in UVB-induced immune suppression?
Amphiregulin mediates UVB-induced immune suppression.
What is the effect of UVB on the production of interleukin-10 and its implications?
UVB exposure increases the production of interleukin-10, which has immunosuppressive effects and can influence the skin’s immune response.
What is the role of amphiregulin in UVB-induced immune suppression?
Amphiregulin is implicated in mediating UVB-induced immune suppression, highlighting its role in the skin’s response to UV exposure.
How does the apoptosis of mast cells due to UVA1 affect skin immune responses?
The apoptosis of mast cells due to UVA1 can lead to reduced histamine release and altered immune responses in the skin, impacting inflammation.
What is the rationale for using PUVA in sclerotic skin diseases?
The rationale for using PUVA in sclerotic skin diseases is its ability to increase MMPs, which aids in collagen remodeling and skin flexibility.
What is the effect of phototherapy on melanogenesis in patients with photosensitivity disorders?
Phototherapy stimulates melanogenesis, which can decrease its efficacy unless UVR doses are gradually increased. In patients with photosensitivity disorders, this effect can be therapeutically exploited, allowing them to tolerate greater amounts of ambient sun exposure.
How do arc or gas discharge lamps function in phototherapy?
Arc or gas discharge lamps are the first effective artificial UVR sources used for phototherapy. They work by passing a high voltage across two electrodes in the presence of gas, exciting the gas atoms. The type of gas determines the emitted wavelengths, and the addition of metal halides broadens the output spectrum, allowing for shorter treatment times.
What are the characteristics of fluorescent lamps used in phototherapy?
Fluorescent lamps are commonly used sources of therapeutic UVR. They contain phosphors that absorb and reemit light at lower energy (longer wavelength). The output is determined by the specific phosphor, and modified fluorescent lamps can emit largely at 311 nm, which is desirable for phototherapy.
What is the significance of narrowband UVB in phototherapy?
Narrowband UVB (NB-UVB) has become a preferred treatment for psoriasis, leading some dermatologists to conclude that broadband UVB (BB-UVB) is obsolete. NB-UVB is more effective and is commonly delivered using fluorescent lamps that emit UVR over a broad spectral range.
What is the relationship between melanogenesis and the efficacy of phototherapy?
The stimulatory effects on melanogenesis can decrease the efficacy of phototherapy unless the doses of UVR are gradually increased.
How can patients with photosensitivity disorders benefit from phototherapy?
Patients with some photosensitivity disorders can exploit the biologic effect of melanogenesis to tolerate greater amounts of ambient sun exposure through phototherapy.
What types of devices are used in phototherapy and how are they tailored to patients?
Phototherapy devices include booth-like devices, smaller stationary devices for specific regions, and handheld devices. The type of device used needs to be individually tailored to each patient.
What is the function of filters and fluorophores in phototherapy devices?
Filters and fluorophores are used to modify the output of phototherapy devices such that the desired wavelengths of therapeutic UVR are emitted.
What are the characteristics of incandescent lamps used in phototherapy?
Incandescent lamps generate UVR by passing an electric current through a thin tungsten filament, which generates heat and light. They are relatively inefficient and have a short lifespan, but can be sealed in a quartz envelope to emit more energetic photons.
How do arc lamps generate UVR for phototherapy?
Arc lamps generate UVR by passing a high voltage across two electrodes in the presence of gas, causing the gas atoms’ electrons to become excited, creating an electric arc that emits light when the electrons return to their ground state.
What is the significance of the type of gas used in arc lamps for phototherapy?
The type of gas incorporated into arc lamps determines the wavelengths emitted. High-pressure arc lamps typically contain mercury or xenon gas, while low-pressure arc lamps use fluorescent materials.
What are the advantages of metal halide lamps in phototherapy?
Metal halide lamps provide a high output that allows for shorter treatment times, although they are costlier and more difficult to operate than fluorescent lamps.
What role do phosphors play in fluorescent lamps used for phototherapy?
Phosphors in fluorescent lamps absorb and reemit light, converting higher energy light into lower energy light suitable for phototherapy, particularly in the UVB and UVA ranges.
What is the difference between broadband UVB and narrowband UVB in phototherapy?
Broadband UVB (BB-UVB) was originally used for psoriasis therapy but has become largely obsolete with the development of narrowband UVB (NB-UVB), which is now preferred for its efficacy.
What is the significance of the minimal erythema dose (MED) in phototherapy?
The minimal erythema dose (MED) is determined by exposing six 1-cm² areas of skin to gradually increasing amounts of UV radiation. Phototherapy is initiated at 50% to 70% of the smallest UV dose that results in uniform erythema over the entire area, ensuring effective treatment while minimizing adverse effects.
How does the initial dose of phototherapy differ between MED-based and Fitzpatrick skin phototype methods?
- MED-based method: The initial dose is determined by the minimal erythema dose, which is assessed through skin exposure and examination after 24 hours.
- Fitzpatrick skin phototype method: The initial dose is established empirically based on the patient’s skin type, with subsequent exposures adjusted according to the patient’s response to treatment.
What are the recommended modifications to phototherapy doses for patients who experience erythema or miss treatments?
Reason for Modification | Modification of Dose |
|————————|———————|
| No erythema | Increase by 25% |
| Erythema with pain | No increase |
| Erythema with pain and blistering | Hold treatment until symptoms subside, then reduce dose by 50% from last dose |
| <1 week | No increase in dose |
| 1 to 2 weeks | Decrease dose by 50% (BB-UVB) or 25% (NB-UVB or PUVA) |
| 2 to 3 weeks | Decrease dose by 75% (BB-UVB) or 50% (NB-UVB or PUVA) |
| >3 weeks | Restart at initial exposure dose |
What wavelengths are most effective for treating psoriasis and causing erythema?
- The wavelengths that most efficiently clear psoriasis are approximately 313 nm.
- Wavelengths less than 300 nm are the most efficient at causing erythema and nonmelanoma skin cancer.
What is the difference in photoadaptation between NB-UVB and BB-UVB?
NB-UVB is considerably less photoadaptive compared to BB-UVB, indicating that NB-UVB requires less adjustment in dosage over time. This difference highlights the importance of wavelength on epidermal thickening and the need for higher subsequent MEDs when treated with BB-UVB.
What is the significance of the wavelength range between 308 and 313 nm in phototherapy?
The wavelength range between 308 and 313 nm is significant in phototherapy because it is emitted by NBUVB light sources, which are effective in treating psoriasis and have largely supplanted BB-UVB sources. This range is optimal for clearing psoriasis while minimizing the risk of erythema and nonmelanoma skin cancer.
How is the minimal erythema dose (MED) determined for phototherapy?
The minimal erythema dose (MED) is determined by exposing six 1-cm² areas of skin to gradually increasing amounts of UV radiation from the same device that will be used for phototherapy. After 24 hours, the areas are examined, and phototherapy is initiated at 50% to 70% of the smallest UV dose that results in uniform erythema over the entire area.
What factors influence the initial starting dose of BB-UVB and NBUVB in phototherapy?
The initial starting dose of BB-UVB and NBUVB is influenced by either the minimal erythema dose (MED) determined through skin exposure or empirically based on Fitzpatrick skin phototype. Subsequent doses are adjusted based on the patient’s response to treatment.
What adjustments should be made if a patient experiences erythema during phototherapy?
If a patient experiences erythema during phototherapy, the dose should be reduced or the treatment delayed, depending on the severity of the erythema response. This ensures patient safety and minimizes the risk of adverse effects.
What is the maximum dose of NB-UVB that should be administered based on skin type?
The maximum dose of NB-UVB that should be administered is between 2000 to 5000 mJ/cm², depending on the photoreactive skin type of the patient. This range helps to optimize treatment efficacy while minimizing the risk of adverse reactions.
How does NB-UVB compare to BB-UVB in terms of photoadaptation?
NB-UVB is considerably less photoadaptive compared to BB-UVB, which means that patients treated with BB-UVB may require higher subsequent minimal erythema doses (MEDs) due to increased epidermal thickening. This highlights the importance of wavelength in determining treatment protocols.
What modifications should be made to phototherapy doses if a patient misses treatments?
If a patient misses treatments, the following modifications should be made:
- <1 week: No increase in dose.
- 1 to 2 weeks: Decrease dose by 50% (BB-UVB) or 25% (NB-UVB or PUVA).
- 2 to 3 weeks: Decrease dose by 75% (BB-UVB) or 50% (NB-UVB or PUVA).
- > 3 weeks: Restart at initial exposure dose.
What role does the Fitzpatrick skin phototype play in determining phototherapy doses?
The Fitzpatrick skin phototype plays a crucial role in determining phototherapy doses as it helps establish the initial dose empirically. Subsequent exposures are adjusted based on the patient’s skin type and response to treatment, ensuring personalized and effective therapy.
What is the clinical significance of using a semiautomated handheld device to determine MED?
The clinical significance of using a semiautomated handheld device to determine MED lies in its high correlation with conventional methods and low interobserver variability. This enhances the accuracy and consistency of determining the appropriate UV dose for phototherapy.
Why is it important to limit output below 290 nm in BB-UVB and NB-UVB devices?
Limiting output below 290 nm in BB-UVB and NB-UVB devices is important because wavelengths in this range are more efficient at causing erythema and nonmelanoma skin cancer. This design helps maximize therapeutic efficacy while minimizing harmful side effects.
What are the three forms of psoralen used in PUVA phototherapy?
The three forms of psoralen used in PUVA phototherapy are:
- 8-methoxypsoralen (8-MOP)
- 5-methoxypsoralen (5-MOP)
- 4,5,8-trimethylpsoralen
In the United States, only 8-MOP is available.
How is the minimum phototoxic dose determined in PUVA therapy?
The minimum phototoxic dose is determined by:
- Having the patient take the dose of the oral psoralen to be used for the photochemotherapy treatment.
- Exposing six 1-cm² areas of skin to gradually increasing doses of UVA.
- Evaluating the minimum phototoxic dose 72 hours after UVA exposure, which is the lowest amount of UVA that produces a uniform erythema over the entire area.
What is the typical treatment schedule for PUVA therapy?
In PUVA therapy, treatments are typically given:
- 2 to 4 times per week
- Avoiding consecutive days
- The amount of UVA given is increased with each treatment.
What are the common adverse effects of phototherapy, particularly PUVA?
The most common short-term adverse effects of phototherapy, particularly PUVA, include:
- Sunburn-like reactions (UVB phototoxicity) that usually peak at 12 to 24 hours.
- Severe burns can produce systemic toxicity with fever and malaise.
- Severe PUVA burns can lead to epidermal sloughing and may require hospital admission.
What is the purpose of using psoralens in bathwater for PUVA therapy?
Using psoralens in bathwater for PUVA therapy serves several purposes:
- Provides a uniform drug distribution over the skin surface.
- Associated with very low psoralen plasma levels.
- Results in a rapid elimination of free psoralens from the skin, circumventing gastrointestinal side effects and possible phototoxic hazards to the eyes associated with the oral form.
What is the typical duration of bath PUVA immersion and its starting dose?
Bath PUVA typically consists of 15 to 20 minutes of whole-body immersion in solutions of 1 mg 8-MOP per liter of body temperature bathwater. It is started at 30% of the minimum phototoxic dose.
What are the common short-term adverse effects of phototherapy?
The most common short-term adverse effects of phototherapy include:
- Sunburn-like reactions due to UVB phototoxicity, usually peaking at 12 to 24 hours.
- Severe PUVA burns can occur, manifesting at 24 to 48 or even 72 hours, leading to systemic toxicity, fever, malaise, and pain.
How should a burn reaction from PUVA therapy be managed?
To manage a burn reaction from PUVA therapy:
1. Avoid giving PUVA treatments on consecutive days to prevent exacerbation.
2. Follow the dose adjustments specified in Table 198-5 for UVB or UVA in the event of a burn reaction.
3. Burns over limited body areas can be managed with local application of an appropriate sunscreen before or during treatment.
What is the significance of skin phototype in initiating PUVA therapy?
In the United States, PUVA therapy is commonly initiated based on the skin phototype. This approach helps to tailor the treatment to the individual’s skin response to UV radiation, ensuring safety and efficacy.
What is the role of psoralen-containing cream in PUVA therapy?
Psoralen-containing cream is used to enhance the effectiveness of PUVA therapy by providing localized treatment and potentially reducing systemic side effects.
What is the role of psoralen-containing cream in PUVA therapy?
Psoralen-containing cream can be used to treat local and more widespread disease. Patients apply the cream and are exposed to UVA irradiation thirty minutes after application, allowing for targeted treatment with potentially fewer systemic side effects.
What precautions should be taken to avoid phototoxic reactions during PUVA therapy?
To avoid phototoxic reactions during PUVA therapy:
- Ensure treatments are not given on consecutive days.
- Monitor for signs of burns and manage them appropriately.
- Use appropriate sunscreens on limited body areas to protect against UV exposure.
What is the significance of UVA1 phototherapy in terms of skin penetration compared to UVB and UVA2?
UVA1 phototherapy (340 to 400 nm) can penetrate deeper into the skin than UVB or shorter-range UVA (UVA2, 320 to 340 nm).
What are the advantages of targeted phototherapy?
Advantages of targeted phototherapy include:
- Sparing normal skin, allowing higher fluences to diseased skin.
- Effective for treatment-resistant lesions and difficult locations (e.g., scalp, chin, nails).
- Handheld devices may be less intimidating for young children compared to phototherapy booths.
What are the limitations of targeted phototherapy?
Limitations of targeted phototherapy include:
- High device expense and impracticality for patients with >10-20% body surface area involvement.
- Typically used for specific conditions like psoriasis, vitiligo, and cutaneous T-cell lymphoma.
What safety considerations should be taken into account when using phototherapy?
Safety considerations for phototherapy include:
- Regular equipment checks by clinical staff or manufacturers.
- Awareness of the risk of overtreatment and potential adverse events, which vary by device.
- Long-term studies indicate increased risks with PUVA therapy, while newer therapies like NB-UVB and UVA1 are relatively safe.
How does the carcinogenic risk of PUVA treatment compare to UVB treatment?
The carcinogenic risk of a single PUVA treatment is approximately 7 times greater than that of a single UVB treatment.
What are the potential side effects of PUVA therapy?
Potential side effects of PUVA therapy include drug intolerance and adverse reactions from the combined action of psoralens and UVA radiation.
What is the significance of developing tolerance to UV-irradiated skin in phototherapy?
Tolerance to UV-irradiated skin allows for progressively larger doses to be administered for optimal therapeutic effect. However, this tolerance is rapidly lost when exposures cease, necessitating adjustments in dosage after as little as 1 week to avoid burns.
How does UVA1 phototherapy differ from UVA2 in terms of penetration and dosing?
UVA1 phototherapy (340 to 400 nm) penetrates deeper into the skin compared to UVA2 (320 to 340 nm). UVA1 is typically administered 3 to 5 times per week with dosing regimens categorized as low (10 to 30 J/cm²), medium (40 to 70 J/cm²), and high (130 J/cm²).
What are the advantages of targeted phototherapy compared to traditional phototherapy?
Targeted phototherapy spares normal skin, allowing higher fluences to be delivered to diseased skin while reducing the risk of side effects. It can be used on treatment-resistant lesions and in difficult locations, and its handheld devices may be less intimidating for young children.
What limitations exist for the use of targeted phototherapy?
Limitations include the expense of devices and impracticality for patients with more than 10% to 20% body surface area involvement. Additionally, while effective, targeted phototherapy may not be suitable for all patients or conditions.
What safety considerations should be taken into account when using phototherapy devices?
Regular checks by clinical staff or manufacturers are essential to ensure equipment functionality, as bulb output may change over time. While phototherapy is generally safe, the risk of overtreatment exists, and long-term studies have shown increased risks associated with certain therapies like PUVA.
What is the carcinogenic risk associated with PUVA treatment compared to UVB treatment?
The carcinogenic risk of a single PUVA treatment is approximately 7 times greater than that of a single UVB treatment, highlighting the need for careful consideration when choosing treatment options.
How does the use of monochromatic light sources in targeted phototherapy benefit treatment?
Monochromatic light sources, such as excimer lasers, allow for precise delivery of therapeutic doses to specific areas, minimizing exposure to surrounding healthy skin and potentially enhancing treatment efficacy for conditions like psoriasis and vitiligo.
What are the potential acute side effects of PUVA therapy?
Potential acute side effects of PUVA therapy include drug intolerance and adverse reactions resulting from the combined action of psoralens and UVA radiation, necessitating careful patient monitoring.
What is the role of automatic calibration in targeted phototherapy devices?
Automatic calibration in targeted phototherapy devices ensures that treatments are delivered with predetermined dosages, enhancing safety and efficacy while reducing the risk of overtreatment.
What are the implications of long-term exposure to BB-UVB therapy?
Long-term exposure to BB-UVB therapy, when combined with topical tar preparations, has not been associated with an increased risk of squamous cell carcinoma (SCC), making it a safer option for chronic skin conditions.
What are the common side effects of Oral 8-MOP in phototherapy?
Common side effects of Oral 8-MOP include:
- Nausea (10% of patients)
- Vomiting
- Nervousness
- Insomnia
- Depression
Nausea may be minimized by taking it with milk, food, or ginger, or by dividing the dose into two portions taken 30 minutes apart.
What is the significance of PUVA lentigines in patients undergoing PUVA therapy?
PUVA lentigines are small brown macules that indicate chronic exposure to PUVA. They are characterized by:
- Proliferation of large melanocytes
- Increased size of melanosomes
- Clustering and binucleation
- Nuclear hyperchromatism and cellular pleomorphism
The presence of these lesions is directly related to the number of PUVA treatments and total UVA dose, serving as an indicator of a lower risk of PUVA malignancy.
How does the risk of skin cancer change with the number of PUVA treatments?
The risk of nonmelanoma skin cancer and possibly malignant melanoma increases in a dose-dependent manner with PUVA treatments. For instance:
- Patients treated with at least 337 PUVA treatments exhibited a 100-fold increased risk of squamous cell carcinoma (SCC) compared to expected rates.
- Individuals with a history of more than 200 PUVA treatments are considered at higher risk for melanoma and may face contraindications for further therapy.
What protective measures are recommended for individuals undergoing PUVA therapy?
Protective measures for individuals undergoing PUVA therapy include:
- Use of genital shielding pouches, surgical masks, and towels to protect against UV exposure.
- Awareness that commonly used protective agents may provide insufficient protection due to increased porosity and decreased mass.
- Monitoring for phototoxic reactions, especially in patients with darker skin, as they may be at higher risk for melanoma.
What are the potential effects of combining PUVA therapy with methotrexate?
Combining PUVA therapy with methotrexate for at least 36 months significantly increases the risk of lymphoma, with incidence rates more than 7 times higher than those who did not take methotrexate during the study.
What are the common side effects associated with oral 8-MOP treatment in phototherapy?
Common side effects of oral 8-MOP include:
- Nausea (10% of patients)
- Vomiting
- Nervousness
- Insomnia
- Depression
These side effects are more prevalent with liquid preparations than with crystalline preparations.
How can nausea from oral 8-MOP be minimized during treatment?
Nausea from oral 8-MOP can be minimized by:
1. Taking 8-MOP with milk, food, or ginger.
2. Dividing the dose into two portions taken approximately 30 minutes apart.
What is the significance of erythema appearing within 24 hours after PUVA treatment?
Erythema appearing within 24 hours after PUVA treatment may signal a potentially severe phototoxic reaction, which can worsen over the next 24 hours. Patients should be protected from further UVA exposures and monitored closely until the erythema resolves.
What are PUVA lentigines and how do they differ from solar lentigines?
PUVA lentigines are small brown macules with irregular borders and uneven pigmentation, characterized by:
- Proliferation of large melanocytes
- Increased size of melanosomes
- Clustering and binucleation
- Nuclear hyperchromatism and cellular pleomorphism
In contrast, solar lentigines do not display these specific histological features.
What is the relationship between PUVA treatment and the risk of developing skin cancer?
The risk of nonmelanoma skin cancer and possibly malignant melanoma increases in a dose-dependent manner with PUVA treatment. Patients treated with at least 337 PUVA treatments exhibited a 100-fold increased risk of squamous cell carcinoma (SCC) compared to expected population incidence rates.
How does concurrent use of oral retinoids affect the risk of SCC in patients undergoing PUVA therapy?
Oral retinoids used concurrently with PUVA therapy reduce the risk of squamous cell carcinoma (SCC) in patients, contrasting with the increased risk associated with the use of cyclosporine during PUVA treatment.
What precautions should be taken for individuals treated with PUVA regarding genital malignancies?
Individuals treated with PUVA are at increased risk of cutaneous malignancies of the genitalia. Standard protection of the genitalia during phototherapy is recommended due to a 90-fold increased risk of genital tumors among patients exposed to high doses of PUVA compared to the general population.
What factors contribute to the development of melanoma in patients undergoing PUVA therapy?
Factors contributing to the development of melanoma in patients undergoing PUVA therapy include:
- A personal or family history of melanoma
- A history of more than 200 PUVA treatments
- Development of a phototoxic reaction, which is more common in individuals with lighter skin.
What are the rare side effects associated with PUVA treatment?
Very rare side effects of PUVA treatment include:
- Polymorphous light eruption-like rashes
- Acneiform eruptions
- Subungual hemorrhages
- Onycholysis
- Occasionally hypertrichosis of the face
These effects typically resolve when treatment is discontinued.
What is the significance of BRAF mutations in PUVA lentigines?
BRAF mutations have been found in PUVA lentigines, but the full significance of this finding is not yet understood. The presence of these lesions is directly related to the number of PUVA treatments and total UVA dose administered, serving as an indicator of a lower risk of PUVA malignancy.
What are the potential ocular effects of UVA exposure during phototherapy?
UVA is absorbed in the lens, leading to various ocular problems such as cataracts, conjunctival hyperemia, and decreased lacrimation. The accumulation of protein-bound 8-MOP in the lens increases the risk of irreversible opacification.
What are the reported side effects of UVA1 phototherapy?
Reported side effects of UVA1 phototherapy include intense tanning, erythema, pruritus, urticaria, tenderness, burning sensation, polymorphous light eruption, eczema herpeticum, and bacterial superinfection.
What considerations should be taken into account for HIV patients undergoing phototherapy?
Phototherapy is generally considered safe for HIV patients. However, UVR may activate HIV and UVB therapy can increase HIV-1 gene expression in the skin. BB-UVB phototherapy does not appear to affect plasma HIV levels or CD4 counts, and phototherapy is recommended as a first-line treatment for moderate to severe psoriasis in HIV-positive patients.
What are the recommendations for phototherapy in children?
NB-UVB is now preferred over PUVA for children due to fewer side effects, which include phototoxicity, carcinogenicity, photoaging, and potential cataract development associated with PUVA.
What precautions should be taken for elderly patients receiving phototherapy?
Elderly patients should be considered for phototherapy if they have no physical or cognitive disabilities. UVB-induced erythema lasts longer and peaks later in this population, and photoadaptation may be decreased. It is advisable to start at a lower dose and increase slowly to limit phototoxic events.
What are the risks associated with phototherapy for patients with a history of arsenic exposure?
Patients with a history of arsenic exposure are at increased risk for cutaneous malignancies and should avoid phototherapy due to this heightened risk.
What is the relative contraindication for phototherapy in transplantation patients?
Transplantation patients have a much higher risk of skin cancer due to medications taken to prevent organ rejection, making phototherapy a relative contraindication for these patients.
What are the potential ocular effects of UVA exposure during phototherapy?
UVA exposure during phototherapy can lead to various ocular problems, including:
- Cataracts
- Conjunctival hyperemia
- Decreased lacrimation
What are the reported side effects of UVA1 phototherapy?
The reported side effects of UVA1 phototherapy include:
- Intense tanning
- Erythema
- Pruritus
- Urticaria
- Tenderness
- Burning sensation
- Polymorphous light eruption
- Eczema herpeticum
- Bacterial superinfection
What considerations should be taken into account when administering phototherapy to HIV-positive patients?
When administering phototherapy to HIV-positive patients, consider the following:
- Safety concerns: UVR may activate HIV by inducing nuclear factor B.
- HIV-1 gene expression: UVB therapy can increase HIV-1 gene expression in the skin.
- BB-UVB phototherapy: It does not appear to affect plasma HIV levels or CD4 counts.
- Recommended treatment: For moderate to severe psoriasis, phototherapy and antiretrovirals are recommended as first-line therapeutic agents.
What are the preferred phototherapy options for children and why?
For children, NB-UVB is now preferred over PUVA for most skin conditions due to:
- Lower risk of side effects: PUVA is associated with phototoxicity, carcinogenicity, photoaging, and potential cataract development.
- Safety profile: NB-UVB is considered safer for pediatric use.
What precautions should be taken when administering phototherapy to pregnant patients?
When administering phototherapy to pregnant patients, consider the following precautions:
- Monitor serum folic acid levels: High cumulative doses of NB-UVB and BB-UVB can cause a decrease in serum folic acid levels.
- Timing: Measure folic acid levels intermittently, especially during the first trimester, to ensure maternal and fetal health.
What factors should be considered when administering phototherapy to elderly patients?
When administering phototherapy to elderly patients, consider the following factors:
1. Age: Patients older than 65 years should be evaluated for physical and cognitive disabilities that may impair phototherapy use.
2. Erythema response: UVB-induced erythema lasts longer and peaks later in the elderly.
3. Photoadaptation: May be decreased due to reduced epidermal turnover, melanocyte number, and tanning response.
4. Dosing: Initiate phototherapy at a lower dose and increase slowly to limit phototoxic events.
What factors should be considered when administering phototherapy to elderly patients?
Consider age, erythema response, photoadaptation, and dosing.
Patients older than 65 years should be evaluated for physical and cognitive disabilities that may impair phototherapy use.
What are the risks associated with phototherapy in patients with a history of arsenic exposure?
Patients with a history of arsenic exposure are at an increased risk for cutaneous malignancies and should avoid phototherapy due to the heightened risk of skin cancer.
What is the relative contraindication for phototherapy in transplantation patients?
Transplantation patients have a much higher risk of skin cancer due to medications taken to prevent organ rejection, making phototherapy a relative contraindication.
What should be considered regarding photosensitizing medications during phototherapy?
It is advisable to avoid photosensitizing medications theoretically, but many patients receive phototherapy while taking such medications.
Reports indicate an association between chronic use of voriconazole and aggressive cutaneous malignancies, including melanoma.
What are the primary mechanisms of action for BB-UVB and NB-UVB in treating psoriasis?
The primary mechanisms include effects on DNA, induction of anti-inflammatory cytokines, augmentation of vitamin D levels, alterations in antimicrobial peptides, modulation of vascular endothelial growth factor, restoration of Th17/Treg imbalance, suppression of Type I interferon signaling, and reduction in CRP.
How does NB-UVB compare to BB-UVB in the treatment of chronic plaque psoriasis?
NB-UVB is superior to BB-UVB in clearing and remission times, and it clears T cells more efficiently from psoriatic plaques.
What is the Goeckerman regimen and its significance in phototherapy for psoriasis?
The Goeckerman regimen involves applying tar-containing topical agents with subsequent UV irradiation and using liquid carbonis detergens with NB-UVB.
It is significant because it is safe, convenient, effective, and leads to more rapid improvement of psoriasis than light therapy alone.
What are the benefits of combining NB-UVB with oral retinoids in psoriasis treatment?
Combining NB-UVB with oral retinoids increases efficacy, reduces the total number of treatments necessary, and may lead to quicker results.
What are the implications of using PUVA in combination with methotrexate for psoriasis treatment?
The combination reduces treatment duration, number of exposures, and total UVA dose required for clearing, and is effective for patients unresponsive to PUVA alone.
Long-term methotrexate use in combination with PUVA may increase the risk of lymphoma.
What is the significance of wavelengths in the range of 313 nm for treating psoriasis?
Wavelengths in the range of 313 nm are most effective at clearing psoriasis, optimizing the therapeutic effects of UVB radiation.
How does the Goeckerman regimen enhance the treatment of psoriasis?
The regimen enhances treatment by applying tar-containing topical agents with UV irradiation and using liquid carbonis detergens with NB-UVB, leading to more rapid improvement than light therapy alone.
What role do oral retinoids play in the treatment of chronic plaque-type psoriasis?
Oral retinoids, such as acitretin, increase treatment efficacy and can reduce the total number of treatments necessary.
What are the potential benefits of combining NB-UVB with methotrexate in psoriasis treatment?
Combining NB-UVB with methotrexate can accelerate lesion clearance, enable quicker results, and reduce treatment duration.
What is the clinical significance of using topical lubricants with UVB therapy?
Topical lubricants improve UVB transmission and increase efficacy by decreasing scatter from scales in the stratum corneum.
How does the use of monochromatic excimer laser compare to conventional phototherapy for psoriasis?
Monochromatic excimer laser is effective and safe, requiring fewer patient visits than conventional phototherapy, thus improving compliance and treatment efficiency.
What are the implications of polymorphisms in genes encoding glutathione S-transferases for PUVA treatment?
Polymorphisms in these genes are associated with PUVA sensitivity, which may have implications for treatment response, indicating that genetic factors can influence the effectiveness of PUVA therapy in patients.
What is the recommended approach for transitioning patients to maintenance therapy after clearing psoriasis with PUVA?
Upon clearing, patients are often transitioned to maintenance therapy, during which the frequency of treatments is gradually reduced to maintain skin health and prevent relapse.
What is the recommended combination for PUVA therapy to enhance its efficacy?
The combination of PUVA therapy with a daily oral retinoid (such as etretinate, acitretin, or isotretinoin) is recommended, referred to as RePUVA. This regimen is typically administered 5 to 10 days before initiating PUVA and continued throughout the clearing phase.
What are the effects of oral retinoids when combined with PUVA therapy?
Oral retinoids combined with PUVA have been shown to reduce the risk of squamous cell carcinoma (SCC) by 30%, although they do not alter the incidence of basal cell carcinoma. This effect is thought to result from accelerated desquamation that optimizes the optical properties of the skin.
What is the role of topical tazarotene in PUVA therapy?
Topical tazarotene gel (0.1%) combined with oral PUVA accelerates the response to treatment. Due to its photosensitizing effect, it is recommended that PUVA therapy be initiated at slightly lower doses than usual.
What is the effect of Narrowband Ultraviolet B (NB-UVB) compared to bath PUVA for treating atopic dermatitis?
NB-UVB is highly effective and preferred by patients compared to bath PUVA. It improves severity scores, reduces the use of potent topical steroids, and provides long-term benefits. Relief of pruritus usually occurs within the first 2 weeks, prior to visible resolution of lesions.
What are the potential side effects of NB-UVB therapy?
The most common side effect of NB-UVB therapy is erythema. Other rare adverse reactions include herpes simplex reactivation. Long-term studies have not shown an increase in the incidence of UV-induced skin tumor growth with the use of tacrolimus or pimecrolimus.
What is the effectiveness of oral PUVA for atopic dermatitis?
Oral PUVA is highly effective for the treatment of atopic dermatitis, but it may require a relatively high number of treatments for clearance. A rebound effect may occur if the therapy is not combined with other treatments or if maintenance therapy is not instituted.
What is the significance of using UVA1 phototherapy for atopic dermatitis?
UVA1 phototherapy is a highly effective, nonsteroidal therapeutic alternative for the treatment of acute exacerbations of atopic dermatitis.
What is the recommended approach for combining cyclosporine with PUVA therapy?
The combination of cyclosporine with PUVA is not recommended due to the greatly increased risk of squamous cell carcinoma.
How does RePUVA therapy enhance the efficacy of PUVA treatment?
RePUVA therapy, which combines PUVA with a daily oral retinoid, can reduce the number of PUVA exposures by one-third and the total cumulative UVA.
What is the effect of oral retinoids when combined with PUVA therapy?
Oral retinoids combined with PUVA have been shown to reduce the risk of squamous cell carcinoma (SCC) by 30%, although they do not alter the incidence of basal cell carcinoma.
What is the significance of using topical tazarotene with PUVA therapy?
Topical tazarotene gel 0.1% combined with oral PUVA accelerates the response to treatment and is clinically superior to vehicle plus PUVA bath therapy.
What precautions should be taken when using calcipotriene with PUVA therapy?
Calcipotriene should not be applied within 2 hours of phototherapy to avoid hindering the treatment’s effectiveness.
What are the potential side effects of using NB-UVB therapy for atopic dermatitis?
The most common side effect of NB-UVB therapy is erythema, while other adverse reactions such as herpes simplex reactivation are rare.
How does NB-UVB compare to bath PUVA in treating atopic dermatitis?
Both NB-UVB and bath PUVA are highly effective for atopic dermatitis, but NB-UVB is preferred by patients due to its long-term benefits and reduced steroid use.
What is the recommended treatment strategy for patients with photosensitive psoriasis?
The strategy is to temporarily discontinue phototherapy until lesions resolve and then restart at a much lower NB-UVB dose to avoid exacerbation.
What is the role of oral PUVA in treating atopic dermatitis?
Oral PUVA is highly effective for treating atopic dermatitis, but it may require a relatively high number of treatments for clearance.
What is the significance of using excimer laser therapy?
The significance of using excimer laser therapy is not provided in the text.
What is the significance of using excimer laser therapy for atopic dermatitis?
The 308-nm xenon-chloride monochromatic excimer laser is effective in reducing severity and pruritus, particularly useful for atopic dermatitis involving the hands.
What is the potential rebound effect associated with PUVA therapy for atopic dermatitis?
A rebound effect may occur in a high percentage of patients if PUVA therapy is not combined with other therapies or if maintenance therapy is not instituted.
What are the advantages of UVA1 phototherapy for atopic dermatitis?
UVA1 phototherapy is a highly effective, nonsteroidal therapeutic alternative for treating acute exacerbations of atopic dermatitis.
What is the impact of topical psoralens on psoriasis treatment?
Topical psoralens can effectively clear psoriasis but may result in nonuniform distribution on the skin surface and unpredictable phototoxic reactions.
How does the use of salicylic acid before PUVA therapy affect treatment?
The application of salicylic acid in petrolatum just before PUVA therapy is not recommended as it may hinder the penetration of UVA.
What is the clinical significance of using NB-UVB sequentially with cyclosporine?
Using NB-UVB sequentially following cyclosporine can help avoid relapse of disease in patients with atopic dermatitis.
What are the long-term benefits of NB-UVB therapy for atopic dermatitis?
NB-UVB therapy improves severity scores, reduces the need for potent topical steroids, and provides long-term benefits for most patients.
What is the recommended treatment for extensive atopic dermatitis?
In extensive atopic dermatitis, excimer laser therapy is impractical, but it is part of the treatment options.
What is excimer laser therapy?
Excimer laser therapy is impractical, but it is particularly useful for localized areas, especially involving the hands.
What is the effect of PUVA therapy on the incidence of basal cell carcinoma?
PUVA therapy does not alter the incidence of basal cell carcinoma, despite reducing the risk of squamous cell carcinoma.
What is the recommended approach for patients with predisposed photosensitive psoriasis?
Patients should be advised to temporarily discontinue phototherapy until lesions resolve and then restart at a lower NB-UVB dose.
What is the role of topical calcineurin inhibitors in conjunction with phototherapy for atopic dermatitis?
There are no studies evaluating the safety or efficacy of combined phototherapy with topical calcineurin inhibitors for atopic dermatitis in humans.
What is the effect of NB-UVB on pruritus in atopic dermatitis patients?
Relief of pruritus usually occurs within the first 2 weeks of NB-UVB therapy, prior to visible resolution of cutaneous lesions.
What is the significance of the photosensitizing effect of tazarotene in PUVA therapy?
Due to the photosensitizing effect of tazarotene, it is recommended that PUVA therapy be initiated at slightly lower doses than usual.
What are the potential adverse reactions to NB-UVB therapy?
While erythema is the most common side effect, other adverse reactions such as herpes simplex reactivation are rare.
What is the importance of maintaining treatment protocols in PUVA therapy?
Maintaining treatment protocols is crucial as a rebound effect may occur if PUVA therapy is not combined with other therapies or if maintenance therapy is not instituted.
What is the clinical implication of using 8-MOP in psoriasis treatment?
The application of 8-MOP in creams, ointments, or lotions followed by UVA irradiation is effective in clearing psoriasis but may lead to unpredictable reactions.
How does the use of NB-UVB therapy differ in children compared to adults?
There is little information regarding the use of NB-UVB in children, but it is generally well-tolerated and produces excellent responses with no serious side effects.
What is the recommended treatment for patients with atopic dermatitis who are not responding to standard therapies?
For patients not responding to standard therapies, excimer laser therapy may be particularly useful for localized areas, especially involving the hands.
What is the effect of PUVA therapy on the total cumulative UVA dose?
RePUVA therapy can reduce the total cumulative UVA dose by more than one-half when combined with oral retinoids.
What is the significance of the timing of medication application before PUVA therapy?
The timing of medication application, such as avoiding salicylic acid just before PUVA therapy, is crucial to ensure effective UVA penetration.
What are the long-term effects of stopping NB-UVB therapy for atopic dermatitis?
Improvements in atopic dermatitis can be maintained for months after stopping NB-UVB therapy, indicating its long-term benefits.
What is the role of phototherapy in managing acute exacerbations of atopic dermatitis?
UVA1 phototherapy serves as a highly effective, nonsteroidal therapeutic alternative for managing acute exacerbations of atopic dermatitis.
What is the clinical significance of the combination of PUVA and oral therapies?
The clinical significance of the combination of PUVA and oral therapies is not explicitly detailed in the provided text.
What is the clinical significance of the combination of PUVA and oral retinoids?
The combination enhances the efficacy of PUVA therapy, reducing the number of exposures and cumulative UVA dose while lowering the risk of SCC.
What are the two leading treatments for vitiligo?
The two leading treatments for vitiligo are:
1. PUVA
2. NB-UVB
What is the earliest sign of response to NB-UVB therapy in vitiligo patients?
The earliest sign of response to NB-UVB therapy is perifollicular repigmentation.
What factors predict how a patient will respond to NB-UVB therapy for vitiligo?
Factors that predict how a patient will respond to NB-UVB include:
- Ethnic background
- Skin phototype
- The areas treated
- The type of vitiligo
How does NB-UVB therapy affect IL-17 and IL-22 levels in vitiligo patients?
NB-UVB therapy decreases IL-17 and IL-22 levels that are usually elevated in vitiligo.
What is the clinical significance of combining NB-UVB with topical tacrolimus in vitiligo treatment?
Combining NB-UVB with topical tacrolimus (0.3% ointment) enhances therapeutic efficacy, resulting in better outcomes than NB-UVB alone due to a synergistic effect mediated through upregulation of MMP-2 and MMP-9, which enhances melanocyte migration.
What is the reported duration of clinical remissions for NB-UVB therapy in early stage CTC?
Clinical remissions for NB-UVB therapy in early stage CTC are reported to last for 3 to 24.5 months.
What are the side effects associated with NB-UVB therapy compared to PUVA?
NB-UVB therapy has a more favorable safety and side effect profile compared to PUVA, which is associated with more discomfort.
What is the role of maintenance therapy in the treatment of CTCL with PUVA?
Maintenance therapy in the treatment of CTCL with PUVA is individualized and is not standardized; it is essential for managing relapses and prolonging remission after the initial treatment phase.
What are the three phases of treatment for Psoralens and Ultraviolet A (PUVA) therapy?
- Clearing phase
- Maintenance phase
- Monitoring of therapy
What is the earliest sign of response to Narrowband Ultraviolet B (NB-UVB) therapy in vitiligo patients?
The earliest sign of response to the therapy is perifollicular repigmentation.
What factors predict how a patient will respond to NB-UVB therapy for vitiligo?
Factors that predict response include:
- Ethnic background
- Skin phototype
- The areas treated
- The type of vitiligo
How does NB-UVB therapy affect IL-17 and IL-22 levels in vitiligo patients?
NB-UVB therapy decreases IL-17 and IL-22 levels that are usually elevated in vitiligo.
What is the reported duration of clinical remissions for NB-UVB therapy in early stage cutaneous T cell lymphoma (CTCL)?
Clinical remissions for NB-UVB therapy in early stage CTCL are reported to last for 3 to 24.5 months.
What is the significance of combining topical tacrolimus with NB-UVB therapy in vitiligo treatment?
Combining topical tacrolimus 0.3% with NB-UVB therapy results in higher therapeutic efficacy than NB-UVB alone, mediated through upregulation of MMP-2 and MMP-9, enhancing melanocyte migration.
What are the potential risks associated with laser dermabrasion?
The text does not provide specific details on the potential risks associated with laser dermabrasion.
What are the potential risks associated with laser dermabrasion combined with topical steroids and NB-UVB therapy?
The potential risks include pain, delayed wound healing, and hypertrophic scarring.
What is the role of bathwater PUVA therapy with 8-MOP in treating patients who cannot use systemic psoralens?
Bathwater PUVA therapy with 8-MOP is a valuable phototherapeutic alternative for patients who cannot use systemic psoralens.
What is the clinical significance of the combination of PUVA and interferon-2a or low-dose interferon-2b in CTC treatment?
The combination of PUVA with interferon-2a or low-dose interferon-2b can lead to prolonged remissions in patients with tumor-stage CTC.
What is the effect of NB-UVB on the balance of oxidants and antioxidants in vitiligo patients?
NB-UVB therapy helps to restore the balance of oxidants and antioxidants, relieving oxidative stress that plays a role in the pathogenesis of vitiligo.
What is the recommended frequency of administration for NB-UVB therapy in vitiligo treatment?
NB-UVB therapy is administered 3 times per week.
What is the impact of Fitzpatrick skin types IV and V on repigmentation in vitiligo patients undergoing NB-UVB therapy?
In patients with Fitzpatrick skin types IV and V, vitiliginous areas may repigment slightly darker than the surrounding skin, but this resolves after a few months, resulting in a cosmetically acceptable outcome.
What is the significance of the finding that patients who show early initial repigmentation are likely to have a higher percentage of final repigmentation?
Patients who show early initial repigmentation are more likely to achieve a higher percentage of final repigmentation.
What is the significance of initial repigmentation?
Initial repigmentation is more likely to achieve a higher percentage of final repigmentation, indicating a better overall response to therapy.
What are the challenges associated with maintenance therapy in PUVA treatment for CTC?
Maintenance therapy in PUVA treatment for CTC is not standardized and requires individualized schedules, making it challenging to manage effectively.
What is the role of cream PUVA with 8-MOP in patients at high risk of skin cancer?
Cream PUVA with 8-MOP can be considered for patients at high risk of skin cancer, providing targeted UV therapy.
What is the relationship between the type of vitiligo and the response to NB-UVB treatment?
There is no association between the response to NB-UVB treatment and patients’ sex, age, family history of vitiligo, or the extent of body surface involvement, but the type of vitiligo does play a role.
What is the clinical implication of the statement that NB-UVB may be as effective as PUVA for early stage CTC?
The implication is that NB-UVB offers a more favorable safety and side effect profile while being as effective as PUVA for treating early stage CTC.
What is the significance of the statement that PUVA typically is combined with other modalities to produce complete responses?
This indicates that combination therapy may enhance the effectiveness of PUVA, especially in patients with tumor-stage CTC, leading to better treatment outcomes.
What are the potential benefits of using afamelanotide in combination with NB-UVB therapy?
Afamelanotide, an analog of melanocyte-stimulating hormone, combined with NB-UVB may enhance treatment efficacy.
What may enhance treatment efficacy?
Further investigation is needed to determine its specific benefits.
What is the expected relapse rate for patients after one year of NB-UVB treatment for vitiligo?
The relapse rates for patients after one year of NB-UVB treatment range from 25% to 84%.
What is the importance of monitoring therapy in PUVA treatment for CTC?
Monitoring therapy is crucial to assess the effectiveness of treatment and to manage any potential relapses or side effects effectively.
What is the role of skin phototype in predicting the response to NB-UVB therapy?
Skin phototype is one of the factors that can predict how well a patient will respond to NB-UVB therapy, influencing treatment outcomes.
What is the clinical significance of the statement that NB-UVB is poorly tolerated due to pain?
This highlights the need for careful patient management and consideration of pain management strategies when using NB-UVB therapy.
What is the effect of NB-UVB on the levels of FoxP3-expressing cells in vitiligo patients?
NB-UVB therapy increases FoxP3-expressing cells, which helps restore the balance between Th17 and regulatory T cells in vitiligo patients.
What is the significance of the statement that combination therapy is not effective in typical UV therapy-resistant sites such as the hands and feet?
This indicates that certain areas of the body may require alternative treatment strategies, as they do not respond well to standard combination therapies.
What is the expected outcome of using NB-UVB therapy in combination with topical steroids for difficult-to-treat areas?
Using NB-UVB therapy in combination with topical steroids is expected to be significantly effective.
What is the expected effectiveness of topical steroids compared to other treatments for difficult-to-treat areas?
Topical steroids are expected to be significantly more effective than using either treatment alone.
What is the role of palliative treatment in later stages of cutaneous T cell lymphoma (CTCL)?
Palliative treatment aims to reduce the tumor-cell burden and act synergistically with other treatments to improve patient quality of life.
What is the clinical relevance of the statement that maintenance therapy tends to prolong remission in NB-UVB treatment?
This suggests that ongoing maintenance therapy is important for sustaining treatment benefits and preventing relapse in patients receiving NB-UVB therapy.
What is the significance of patients with tumor-stage CTCL exhibiting a high rate of early recurrences?
This indicates that patients with advanced CTCL may require permanent maintenance treatment to manage their condition effectively.
What is the expected outcome of PUVA therapy combined with interferon-2a or low-dose interferon-2b?
The expected outcome is prolonged remissions in patients with tumor-stage CTCL, enhancing the effectiveness of treatment.
What is the importance of individualized schedules in maintenance therapy for PUVA treatment?
Individualized schedules are important to tailor treatment to each patient’s specific needs and responses, optimizing therapeutic outcomes.
What is the significance of targeted phototherapy with a 308-nm excimer laser in the treatment of localized vitiligo?
Targeted phototherapy with a 308-nm excimer laser is considered first-line therapy for localized vitiligo. It is effective in achieving repigmentation.
What is the recommended frequency for achieving repigmentation?
2 to 3 times weekly.
What does the rate of repigmentation depend on?
The total number of sessions rather than the frequency of treatments.
What is the advantage of the excimer laser?
It can deliver higher energy exclusively to affected areas while minimizing side effects.
How does UVA1 treatment affect localized scleroderma?
It can decrease lesional skin thickness, improve skin elasticity, reduce sclerotic plaques, and increase passive range of motion.
What are the typical doses for UVA1 treatment?
60 to 130 J/cm² five times per week, with lower doses also being effective.
What may excessive tanning response interfere with?
Treatment effectiveness.
What are the clinical implications of using NB-UVB as a second-line treatment?
It has been employed in children and adults with graft versus host disease who are resistant to or have relapsed on standard immunosuppressive regimens.
What is important to do for patients receiving NB-UVB treatment?
Regularly examine these patients due to their increased risk of skin cancer from immunosuppressive therapies.
What other treatments have been utilized for graft versus host disease?
Oral PUVA and UVA1, indicating a multi-faceted approach to managing this condition.
What is the effectiveness of UVB phototherapy for pruritus associated with chronic renal failure?
UVB phototherapy is an effective option for treating pruritus.
What is UVB phototherapy effective for?
UVB phototherapy is an effective option for treating pruritus associated with chronic renal failure, with approximately 80% to 90% of patients showing improvement within 2 to 5 weeks.
What is the recommended frequency for targeted phototherapy with a 308-nm excimer laser in localized vitiligo?
2 to 3 times weekly.
How does the excimer laser compare to NB-UVB in terms of repigmentation for vitiligo?
The excimer laser achieves the same grade of repigmentation as NB-UVB but at a lower total cumulative dose.
What is the effect of combining a topical antioxidant gel with excimer laser treatment for vitiligo?
Combining a topical antioxidant gel with the excimer laser appears to have higher efficacy in terms of repigmentation.
What is the role of UVA1 in the treatment of localized scleroderma?
UVA1 decreases lesional skin thickness, improves skin elasticity, reduces sclerotic plaques, and increases passive range of motion.
What dosing regimen is suggested for UVA1 treatment in localized scleroderma?
Administered at a dose of 60 to 130 J/cm², 5 times per week, with lower doses (20 J/cm²) also reported to be effective.
What is the significance of the tanning response when administering UVA1 at higher doses for scleroderma?
When 130 J/cm² was administered 3 times per week, the tanning response interfered with the ability to soften sclerodermatous patches, suggesting that medium dose and less frequent administration may be more effective.
What are sclerodermatous patches suggesting?
Medium dose and less-frequent treatments would be more effective.
What is the mechanism of action (MOA) of UVA1 in treating scleroderma?
UVA1 works partly through induction of MMP-1 and downregulation of transforming growth factor via the SMAD signaling pathway, which correlates with clinical improvement.
What is the effectiveness of NB-UVB as a second-line treatment for graft versus host disease?
NB-UVB has been employed as a second-line treatment in children and adults who are resistant to or have relapsed on standard immunosuppressive regimens.
What are the reported benefits of UVA1 treatment in nephrogenic systemic fibrosis?
UVA1 has led to modest improvement in the degree of induration and in mobility of the hands and legs.
What is the response rate of patients with pruritus associated with chronic renal failure to UVB phototherapy?
Approximately 80% to 90% of patients improve within 2 to 5 weeks of phototherapy.
How does BB-UVB exposure affect pruritus in patients?
BB-UVB exposure to one-half of the body improves pruritus in both the exposed and unexposed sites, indicating a systemic effect.
What is the most effective treatment for cholestatic pruritus according to the text?
Phototherapy is considered by some to be the most effective treatment for cholestatic pruritus.
What is the role of PUVA in treating aquagenic pruritus?
PUVA has shown improvement in aquagenic pruritus in several patients, but maintenance treatments may be required.
What is the clinical significance of using oral PUVA for extensive morphea in children?
Oral PUVA has been used to treat disabling, extensive morphea in children.
What is the impact of UVA1 on systemic scleroderma?
UVA1 has been used to treat acral scleroderma in patients with systemic scleroderma, leading to improvement in skin softening and increased finger movement.
What is the relationship between the duration of morphea and the recurrence of symptoms after UVA1 treatment?
The recurrence after successful UVA1 treatment was dependent on the duration of morphea prior to treatment, rather than morphea subtypes or Fitzpatrick skin type.
What is the effect of combining PUVA with topical corticosteroids for vitiligo treatment?
Combining PUVA with medium-potency topical corticosteroids is 3 times more effective than either treatment alone.
What is the recommended treatment approach for patients with systemic scleroderma and contractures?
Oral and topical PUVA have been used for systemic scleroderma, with improvement in range of motion and contractures.
What is the significance of monitoring patients receiving NB-UVB treatment for graft versus host disease?
It is important to examine the patients regularly, as they have an increased risk of skin cancer from their immunosuppressive therapies.
What are the potential side effects of UVA1 treatment in localized scleroderma?
Higher doses of UVA1 may cause tanning responses that interfere with treatment efficacy, suggesting a need for careful dose management.
What is the clinical implication of using a monochromatic excimer laser for vitiligo treatment?
The monochromatic excimer laser can deliver higher energy exclusively to affected areas while minimizing side effects, making it effective.
What is the effect of UVA1 on repigmentation in localized vitiligo?
UVA1 is effective for vitiligo as it targets affected areas while minimizing side effects.
How does treatment frequency affect the ultimate rate of repigmentation in localized vitiligo?
The ultimate rate of repigmentation is dependent on the total number of sessions rather than the frequency of treatments.
What is the effect of UVA1 on the color difference between normal and vitiliginous skin?
UVA1 does not cause repigmentation but accentuates the color difference by tanning the normal skin.
What is the recommended approach for treating sclerodermatous patches with UVA1?
Medium dose and less-frequent treatments are recommended for better efficacy in softening sclerodermatous patches.
What is the significance of the cumulative dose in UVA1 treatments for nephrogenic systemic fibrosis?
Total treatments can range from 22 (with a cumulative dose of 1855 J/cm²) to 50 treatments (3850 J/cm²), indicating the importance of cumulative dosing for effectiveness.
What is the role of phototherapy in treating pruritus associated with chronic renal failure?
Phototherapy is an effective option for pruritus associated with chronic renal failure, with a high response rate in patients.
What is the clinical significance of using cholestryramine in conjunction with UVB phototherapy?
UVB phototherapy has been combined with cholestryramine to enhance treatment efficacy for cholestatic pruritus.
What is the impact of UVA1 on the treatment of acral sclerosis in systemic scleroderma?
UVA1 treatment has shown improvement in softening affected skin and increasing finger movement in patients with acral sclerosis.
What is the relationship between Fitzpatrick skin type and the effectiveness of NBUVB monotherapy?
NBUVB monotherapy shows significant improvement especially in patients with Fitzpatrick skin types IV through VI.
What is the importance of patient follow-up in the context of graft versus host disease treatment?
Regular follow-up is crucial due to the increased risk of skin cancer from immunosuppressive therapies in these patients.
What is the role of NB-UVB in treating chronic urticaria?
NB-UVB is considered for patients who have failed first-line antihistamine regimens. It is effective and well-tolerated, partly due to greater penetration into the dermis and larger systemic immunosuppressive effects compared to BB-UVB.
What is the proposed mechanism of ‘hardening’ in phototherapy?
The proposed mechanisms of ‘hardening’ include:
1. Thickening of the stratum corneum
2. Hyperpigmentation
3. Modulation of cutaneous immune response by normalizing UV-induced inflammatory cytokines like IL-1
4. Restoration of impaired neutrophil chemotaxis
5. Increasing regulatory T cells and transiently decreasing Langerhans cells in the epidermis while increasing mast cell recruitment into the papillary dermis.
How does PUVA therapy compare to NB-UVB in treating lichen planus?
NB-UVB therapy has shown better initial clinical response for lichen planus compared to PUVA. While NB-UVB can achieve a complete response in 70% of patients after an average of 10 weeks, PUVA tends to have a higher recurrence rate and may prolong the disease.
What are the recommended treatments for chronic hand eczema?
For chronic hand eczema, NBUVB and local baths are recommended.
What are successful treatments for chronic hand eczema?
Narrowband UVB (NB-UVB) and local bath PUVA are successful treatments.
What is the preferred treatment for hyperkeratotic eczema?
Oral PUVA is preferred for hyperkeratotic eczema.
What is more beneficial for dyshidrotic eczema?
Bath PUVA is more beneficial for dyshidrotic eczema.
How does localized UVA1 compare to cream PUVA for chronic vesicular dyshidrotic eczema?
Localized UVA1 has similar efficacy to cream PUVA for chronic vesicular dyshidrotic eczema.
Why is determining the minimal urticarial dose crucial in rush hardening?
Determining the minimal urticarial dose is crucial as it helps to initiate treatment at a dose lower than this threshold to minimize exacerbations.
What is the role of NB-UVB in the treatment of chronic urticaria?
NB-UVB is considered effective and well-tolerated in patients with chronic urticaria who have failed first-line antihistamine regimens.
How does the efficacy of NB-UVB compare to BB-UVB?
NB-UVB may have greater penetration into the dermis and larger systemic immunosuppressive effects compared to BB-UVB, which has a higher relapse rate.
What are the proposed mechanisms of ‘hardening’ in phototherapy for photodermatoses?
The proposed mechanisms include:
1. Thickening of the stratum corneum
2. Hyperpigmentation
3. Modulation of cutaneous immune response by normalizing UV-induced inflammatory cytokines like IL-1
4. Restoration of impaired neutrophil chemotaxis and increase in regulatory T cells
5. Decrease in Langerhans cells and increase in mast cell recruitment in the epidermis.
How does PUVA therapy benefit patients with photodermatoses compared to other treatments?
PUVA therapy offers rapid and intense pigment induction at relatively low UVA doses.
What is the significance of inducing pigment at low UVA doses?
Inducing pigment at relatively low UVA doses helps prevent outbreaks of moderate to severe polymorphous light eruption and can be initiated one month before anticipated sun exposure.
What are the advantages of using novel home UVB low-intensity phototherapy devices?
Novel home UVB low-intensity phototherapy devices allow patients to use the treatment daily for 6 minutes, showing better acceptance while providing the same efficacy as BB-UVB hospital treatments.
What is the significance of determining the minimal urticarial dose in rush hardening?
Determining the minimal urticarial dose is crucial in rush hardening as it helps to initiate treatment at a dose lower than this threshold to minimize exacerbations. This process can lead to ‘hardening’ or ‘desensitization’ in as few as 3 days.
What is the expected outcome of NB-UVB therapy in patients with lichen planus?
NB-UVB therapy has been reported to achieve a complete response in 70% of patients with lichen planus after an average of 10 weeks of treatment, with improvement in pruritus often occurring before the disappearance of skin lesions.
How does oral PUVA compare to bath PUVA in treating chronic hand eczema?
Oral PUVA is preferable for patients with hyperkeratotic eczema, while bath PUVA is more beneficial for dyshidrotic eczema. Bath PUVA may be less effective in smokers with dyshidrotic eczema.
What are the potential risks associated with PUVA therapy in patients with lichen planus?
PUVA therapy has been reported to induce lichen planus and lichen planus pemphigoides in patients undergoing treatment for other skin conditions.
What is the potential risk for patients with emphigoides undergoing treatment for other skin diseases?
There is a potential risk of exacerbating or triggering these conditions.
What is the role of UVA1 in the treatment of chronic urticaria and its effectiveness?
UVA1 has effects on mast cells but is not particularly effective in preventing solar or other forms of urticaria, indicating limited efficacy in this context compared to other treatments.
What is the recommended frequency of NB-UVB therapy for patients with lichen planus?
NB-UVB therapy is typically administered 3 times per week on nonconsecutive days for patients with lichen planus.
What are the effectiveness rates of NB-UVB for pityriasis lichenoides et varioliformis acuta and pityriasis lichenoides chronic?
NB-UVB is effective for both conditions:
- 65% complete response for pityriasis lichenoides et varioliformis acuta
- More than 85% complete response for pityriasis lichenoides chronic.
What is the role of oral PUVA in the treatment of lymphomatoid papulosis?
Oral PUVA has been used for lymphomatoid papulosis, but relapses may occur upon cessation of therapy. Bath PUVA is effective in children with this condition.
Why is oral PUVA reserved for patients with telangiectasia macularis eruptiva persistans?
Oral PUVA is reserved for severe cases because other therapies, such as laser treatment, may be safer long-term, and the response to oral PUVA is often temporary.
How does UVA1 phototherapy affect urticaria pigmentosa?
UVA1 phototherapy ameliorates both objective and subjective symptoms of urticaria pigmentosa in adults, leading to long-term remission in many cases. It also relieves pruritus and decreases urinary histamine.
What does it relieve?
It relieves pruritus and decreases urinary histamine levels.
What is the significance of serum tryptase levels in patients with indolent systemic mastocytosis undergoing PUVA therapy?
Serum tryptase levels trended downward during PUVA therapy, suggesting it may be used as a surrogate marker for response in some patients.
What are the treatment outcomes for patients with granuloma annulare treated with PUVA?
Patients with widespread granuloma annulare treated with PUVA have achieved complete clearance of their disease, and maintenance therapy can result in prolonged disease-free intervals.
What is the mechanism of action of PUVA in granuloma annulare?
The mechanism of action of PUVA in granuloma annulare is unclear, but selective elimination of pathogenic cells may be one explanation.
What is the recommended first-line therapy for chronic plaque psoriasis?
The recommended first-line therapy for chronic plaque psoriasis is NB-UVB.
What is the effectiveness of NB-UVB and BB-UVB in treating pityriasis lichenoides?
NB-UVB and BB-UVB are safe and effective for both chronic pityriasis lichenoides and pityriasis lichenoides et varioliformis acuta, with a complete response reported in 65% of patients with varioliformis acuta and over 85% in chronic patients.
What is the role of oral PUVA in the treatment of lymphomatoid papulosis?
Oral PUVA has been used for patients with lymphomatoid papulosis, but relapses may occur upon cessation of therapy. Bath PUVA is effective in children with this condition.
Why is oral PUVA reserved for telangiectasia macularis eruptiva patients?
Oral PUVA is reserved for patients with telangiectasia macularis eruptiva due to specific treatment considerations.
What is oral PUVA reserved for?
Oral PUVA is reserved for patients with severe disease because other therapies, such as laser treatment, may be safer long-term, and the response to oral PUVA is often temporary.
How does UVA1 phototherapy affect urticaria pigmentosa?
UVA1 phototherapy ameliorates both the objective and subjective symptoms of urticaria pigmentosa in adults, leading to long-term remission in many cases, although lesions may not respond completely.
What is the significance of serum tryptase levels in patients with indolent systemic mastocytosis undergoing PUVA therapy?
In patients with indolent systemic mastocytosis, serum tryptase levels trended downward during PUVA therapy, potentially serving as a surrogate marker for response in some patients.
What are the treatment outcomes for patients with granuloma annulare treated with PUVA?
Patients with widespread granuloma annulare treated with PUVA have achieved complete clearance of their disease, and maintenance therapy may result in prolonged disease-free intervals.
What is the mechanism of action of PUVA in granuloma annulare?
The mechanism of action of PUVA in granuloma annulare is unclear, but selective elimination of pathogenic cells may be one explanation for its effectiveness.
What is the typical treatment regimen for perforating disorders using PUVA?
Patients with perforating disorders are typically treated 2 to 3 times weekly with PUVA, with lesions and symptoms clearing after 10 to 15 treatments, although the mechanism of improvement is unknown.
What is the first-line therapy for chronic plaque psoriasis?
The first-line therapy for chronic plaque psoriasis is NB-UVB.
What is the treatment for chronic plaque psoriasis?
The treatment for chronic plaque psoriasis is NB-UVB.
What is the relationship between long-term methotrexate use and PUVA therapy in terms of lymphoma risk?
Long-term methotrexate use, defined as 36 or more months, in combination with PUVA may increase the risk of lymphoma.
What is the significance of perifollicular repigmentation in vitiligo treatment?
In vitiligo, the earliest sign of response to therapy is perifollicular repigmentation, indicating the effectiveness of the treatment.
What is the recommended approach for rush hardening in phototherapy?
The most important parameter in rush hardening is to determine the minimal urticarial dose and action spectra immediately before starting therapy and to initiate treatment at a dose lower than the minimal urticarial dose to minimize exacerbations.
What are the effects of phototherapy on the immune system?
Phototherapy increases IL-10, cyclooxygenase-2, and prostaglandin E2, while decreasing dendritic cell activity and promoting T-cell apoptosis in lymphoid infiltrates. It also inhibits effector T-cell activation and diminishes cell-mediated immune response.
How does phototherapy affect mast cells?
Phototherapy stabilizes mast cell membranes, decreases histamine release, and induces mast cell apoptosis.
What changes occur in collagen due to phototherapy?
Phototherapy increases reactive oxygen species (ROS), IL-1, IL-6, and MMP-1, leading to collagen degradation.
What are the effects of phototherapy on keratinocytes?
Phototherapy causes acanthosis, thickening of the stratum corneum, and stimulates cytokeratins 15 and 10.
What are the effects of phototherapy on melanocytes?
Phototherapy stimulates melanogenesis.
What are melanocytes?
Melanocytes are cells that produce melanin, contributing to skin pigmentation.
How does phototherapy affect melanogenesis?
Phototherapy stimulates melanogenesis and contributes to skin repigmentation.
In which conditions is phototherapy effective for T-cell hyperactive conditions?
Phototherapy is effective in atopic dermatitis, psoriasis, lichen planus, and cutaneous T-cell lymphoma.
What skin diseases can phototherapy effectively treat?
Phototherapy is effective in mast cell-mediated diseases, sclerotic skin diseases, and some photodermatoses.
What are the effects of phototherapy on the immune system?
Phototherapy increases IL-10, cyclooxygenase-2, and prostaglandin E2, while decreasing dendritic cell activity and promoting T-cell apoptosis in lymphoid infiltrates.
How does phototherapy affect mast cells?
Phototherapy stabilizes mast cell membranes, decreases histamine release, and induces mast cell apoptosis, influencing allergic responses and inflammation.
What role does phototherapy play in collagen metabolism?
Phototherapy increases reactive oxygen species (ROS), IL-1, IL-6, and MMP-1, leading to collagen degradation and potential skin remodeling effects.
What are the effects of phototherapy on keratinocytes?
Phototherapy stimulates keratinocytes, leading to acanthosis, thickening of the stratum corneum, skin ‘hardening’, and repigmentation.
Which skin conditions are effectively treated with phototherapy?
Phototherapy is effective in conditions such as atopic dermatitis, psoriasis, lichen planus, cutaneous T-cell lymphoma, telangiectasia, macularis eruptiva persistans, localized and systemic scleroderma, graft-versus-host disease, and polymorphic light eruption.
