198: Phototherapy Flashcards

Question

What are the effects of PUVA on mast cells?

Answer 1

PUVA stabilizes mast cell membranes and limits histamine release.

Answer 2

UVA1 exposure leads to mast cell apoptosis, reducing their concentrations, unlike PUVA.

Answer 3

Phototherapy activates MMPs, affecting collagen metabolism.

Answer 4

Phototherapy causes acanthosis of the epidermis and thickening of the stratum corneum.

Answer 5

Increased CD54 expression facilitates T-cell binding, enhancing phototherapy efficacy in inflammatory conditions.

Answer 6

Treatment doses must be progressively increased to reach therapeutic targets in the lower epidermis and dermis.

Answer 7

UV exposure significantly lowers levels of immunomodulatory factors like prostaglandin D2.

Answer 8

UVA1 exposure induces ICAM-1 expression in keratinocytes, facilitating T-cell binding.

Answer 9

Phototherapy causes apoptosis of T cells in cutaneous lymphoid infiltrates.

Answer 10

FoxP3-positive regulatory T cells can convert into IL-17-producing cells following UVB exposure.

Answer 11

PUVA stabilization of mast cells may limit histamine release, beneficial for managing allergic responses.

Answer 12

Phototherapy can harden the skin, allowing greater sun exposure tolerance.

Answer 13

UVA1 exposure increases IL-4 expression, associated with the inflammatory response in atopic dermatitis.

Answer 14

UVB exposure biases the equilibrium toward a diminished cell-mediated immune response.

Answer 15

Increased IL-10 levels indicate an immunosuppressive effect influencing the skin's immune response.

Answer 16

Phototherapy increases MMP production, involved in collagen and extracellular matrix remodeling.

Answer 17

UVA radiation increases inflammatory cytokines IL-1 and IL-6, stimulating MMPs and contributing to skin inflammation.

Answer 18

These forms of phototherapy can lead to keratinocyte acanthosis and thickening of the stratum corneum.

Answer 19

UV exposure can induce adhesion molecules like CD54 in keratinocytes.

Answer 20

PUVA stabilizes mast cell membranes, while UVA1 causes apoptosis of mast cells.

Answer 21

MMP activation by phototherapy aids in treating sclerotic skin diseases.

Answer 22

UV exposure leads to a decrease in immunomodulatory factors such as prostaglandin D2.

Answer 23

This interaction is significant for immune responses in the skin, particularly in inflammatory conditions.

Answer 24

Phototherapy modulates the immune response by affecting T cell activation, dendritic cell function, and cytokine production.

Answer 25

Increased CD54 expression may enhance phototherapy efficacy in treating inflammatory skin diseases.

Answer 26

UVB exposure increases interleukin-10 production, which has immunosuppressive effects.

Answer 27

Amphiregulin mediates UVB-induced immune suppression.

Answer 28

UVB exposure increases the production of interleukin-10, which has immunosuppressive effects and can influence the skin's immune response.

Answer 29

Amphiregulin is implicated in mediating UVB-induced immune suppression, highlighting its role in the skin's response to UV exposure.

Answer 30

The apoptosis of mast cells due to UVA1 can lead to reduced histamine release and altered immune responses in the skin, impacting inflammation.

Answer 31

The rationale for using PUVA in sclerotic skin diseases is its ability to increase MMPs, which aids in collagen remodeling and skin flexibility.

Answer 32

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.

Answer 33

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.

Answer 34

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.

Answer 35

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.

Answer 36

The stimulatory effects on melanogenesis can decrease the efficacy of phototherapy unless the doses of UVR are gradually increased.

Answer 37

Patients with some photosensitivity disorders can exploit the biologic effect of melanogenesis to tolerate greater amounts of ambient sun exposure through phototherapy.

Answer 38

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.

Answer 39

Filters and fluorophores are used to modify the output of phototherapy devices such that the desired wavelengths of therapeutic UVR are emitted.

Answer 40

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.

Answer 41

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.

Answer 42

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.

Answer 43

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.

Answer 44

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.

Answer 45

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.

Answer 46

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.

Answer 47

1. MED-based method: The initial dose is determined by the minimal erythema dose, which is assessed through skin exposure and examination after 24 hours. 2. 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.

Answer 48

| 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 |

Answer 49

- 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.

Answer 50

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.

Answer 51

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.

Answer 52

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.

Answer 53

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.

Answer 54

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.

Answer 55

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.

Answer 56

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.

Answer 57

If a patient misses treatments, the following modifications should be made: 1. <1 week: No increase in dose. 2. 1 to 2 weeks: Decrease dose by 50% (BB-UVB) or 25% (NB-UVB or PUVA). 3. 2 to 3 weeks: Decrease dose by 75% (BB-UVB) or 50% (NB-UVB or PUVA). 4. >3 weeks: Restart at initial exposure dose.

Answer 58

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.

Answer 59

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.

Answer 60

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.

Answer 61

The three forms of psoralen used in PUVA phototherapy are: 1. 8-methoxypsoralen (8-MOP) 2. 5-methoxypsoralen (5-MOP) 3. 4,5,8-trimethylpsoralen In the United States, only 8-MOP is available.

Answer 62

The minimum phototoxic dose is determined by: 1. Having the patient take the dose of the oral psoralen to be used for the photochemotherapy treatment. 2. Exposing six 1-cm² areas of skin to gradually increasing doses of UVA. 3. 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.

Answer 63

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.

Answer 64

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.

Answer 65

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.

Answer 66

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.

Answer 67

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.

Answer 68

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.

Answer 69

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.

Answer 70

Psoralen-containing cream is used to enhance the effectiveness of PUVA therapy by providing localized treatment and potentially reducing systemic side effects.

Answer 71

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.

Answer 72

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.

Answer 73

UVA1 phototherapy (340 to 400 nm) can penetrate deeper into the skin than UVB or shorter-range UVA (UVA2, 320 to 340 nm).

Answer 74

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.

Answer 75

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.

Answer 76

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.

Answer 77

The carcinogenic risk of a single PUVA treatment is approximately 7 times greater than that of a single UVB treatment.

Answer 78

Potential side effects of PUVA therapy include drug intolerance and adverse reactions from the combined action of psoralens and UVA radiation.

Answer 79

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.

Answer 80

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).

Answer 81

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.

Answer 82

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.

Answer 83

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.

Answer 84

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.

Answer 85

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.

Answer 86

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.

Answer 87

Automatic calibration in targeted phototherapy devices ensures that treatments are delivered with predetermined dosages, enhancing safety and efficacy while reducing the risk of overtreatment.

Answer 88

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.

Answer 89

Common side effects of Oral 8-MOP include: - Nausea (10% of patients) - Vomiting - Nervousness - Insomnia - Depression ## Footnote Nausea may be minimized by taking it with milk, food, or ginger, or by dividing the dose into two portions taken 30 minutes apart.

Answer 90

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 ## Footnote 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.

Answer 91

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.

Answer 92

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.

Answer 93

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.

Answer 94

Common side effects of oral 8-MOP include: - Nausea (10% of patients) - Vomiting - Nervousness - Insomnia - Depression ## Footnote These side effects are more prevalent with liquid preparations than with crystalline preparations.

Answer 95

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.

Answer 96

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.

Answer 97

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 ## Footnote In contrast, solar lentigines do not display these specific histological features.

Answer 98

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.

Answer 99

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.

Answer 100

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.

Answer 101

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.

Answer 102

Very rare side effects of PUVA treatment include: - Polymorphous light eruption-like rashes - Acneiform eruptions - Subungual hemorrhages - Onycholysis - Occasionally hypertrichosis of the face ## Footnote These effects typically resolve when treatment is discontinued.

Answer 103

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.

Answer 104

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.

Answer 105

Reported side effects of UVA1 phototherapy include intense tanning, erythema, pruritus, urticaria, tenderness, burning sensation, polymorphous light eruption, eczema herpeticum, and bacterial superinfection.

Answer 106

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.

Answer 107

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.

Answer 108

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.

Answer 109

Patients with a history of arsenic exposure are at increased risk for cutaneous malignancies and should avoid phototherapy due to this heightened risk.

Answer 110

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.

Answer 111

UVA exposure during phototherapy can lead to various ocular problems, including: - Cataracts - Conjunctival hyperemia - Decreased lacrimation

Answer 112

The reported side effects of UVA1 phototherapy include: - Intense tanning - Erythema - Pruritus - Urticaria - Tenderness - Burning sensation - Polymorphous light eruption - Eczema herpeticum - Bacterial superinfection

Answer 113

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.

Answer 114

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.

Answer 115

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.

Answer 116

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.

Answer 117

Consider age, erythema response, photoadaptation, and dosing. ## Footnote Patients older than 65 years should be evaluated for physical and cognitive disabilities that may impair phototherapy use.

Answer 118

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.

Answer 119

Transplantation patients have a much higher risk of skin cancer due to medications taken to prevent organ rejection, making phototherapy a relative contraindication.

Answer 120

It is advisable to avoid photosensitizing medications theoretically, but many patients receive phototherapy while taking such medications. ## Footnote Reports indicate an association between chronic use of voriconazole and aggressive cutaneous malignancies, including melanoma.

Answer 121

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.

Answer 122

NB-UVB is superior to BB-UVB in clearing and remission times, and it clears T cells more efficiently from psoriatic plaques.

Answer 123

The Goeckerman regimen involves applying tar-containing topical agents with subsequent UV irradiation and using liquid carbonis detergens with NB-UVB. ## Footnote It is significant because it is safe, convenient, effective, and leads to more rapid improvement of psoriasis than light therapy alone.

Answer 124

Combining NB-UVB with oral retinoids increases efficacy, reduces the total number of treatments necessary, and may lead to quicker results.

Answer 125

The combination reduces treatment duration, number of exposures, and total UVA dose required for clearing, and is effective for patients unresponsive to PUVA alone. ## Footnote Long-term methotrexate use in combination with PUVA may increase the risk of lymphoma.

Answer 126

Wavelengths in the range of 313 nm are most effective at clearing psoriasis, optimizing the therapeutic effects of UVB radiation.

Answer 127

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.

Answer 128

Oral retinoids, such as acitretin, increase treatment efficacy and can reduce the total number of treatments necessary.

Answer 129

Combining NB-UVB with methotrexate can accelerate lesion clearance, enable quicker results, and reduce treatment duration.

Answer 130

Topical lubricants improve UVB transmission and increase efficacy by decreasing scatter from scales in the stratum corneum.

Answer 131

Monochromatic excimer laser is effective and safe, requiring fewer patient visits than conventional phototherapy, thus improving compliance and treatment efficiency.

Answer 132

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.

Answer 133

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.

Answer 134

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.

Answer 135

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.

Answer 136

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.

Answer 137

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.

Answer 138

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.

Answer 139

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.

Answer 140

UVA1 phototherapy is a highly effective, nonsteroidal therapeutic alternative for the treatment of acute exacerbations of atopic dermatitis.

Answer 141

The combination of cyclosporine with PUVA is not recommended due to the greatly increased risk of squamous cell carcinoma.

Answer 142

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.

Answer 143

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.

Answer 144

Topical tazarotene gel 0.1% combined with oral PUVA accelerates the response to treatment and is clinically superior to vehicle plus PUVA bath therapy.

Answer 145

Calcipotriene should not be applied within 2 hours of phototherapy to avoid hindering the treatment's effectiveness.

Answer 146

The most common side effect of NB-UVB therapy is erythema, while other adverse reactions such as herpes simplex reactivation are rare.

Answer 147

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.

Answer 148

The strategy is to temporarily discontinue phototherapy until lesions resolve and then restart at a much lower NB-UVB dose to avoid exacerbation.

Answer 149

Oral PUVA is highly effective for treating atopic dermatitis, but it may require a relatively high number of treatments for clearance.

Answer 150

The significance of using excimer laser therapy is not provided in the text.

Answer 151

The 308-nm xenon-chloride monochromatic excimer laser is effective in reducing severity and pruritus, particularly useful for atopic dermatitis involving the hands.

Answer 152

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.

Answer 153

UVA1 phototherapy is a highly effective, nonsteroidal therapeutic alternative for treating acute exacerbations of atopic dermatitis.

Answer 154

Topical psoralens can effectively clear psoriasis but may result in nonuniform distribution on the skin surface and unpredictable phototoxic reactions.

Answer 155

The application of salicylic acid in petrolatum just before PUVA therapy is not recommended as it may hinder the penetration of UVA.

Answer 156

Using NB-UVB sequentially following cyclosporine can help avoid relapse of disease in patients with atopic dermatitis.

Answer 157

NB-UVB therapy improves severity scores, reduces the need for potent topical steroids, and provides long-term benefits for most patients.

Answer 158

In extensive atopic dermatitis, excimer laser therapy is impractical, but it is part of the treatment options.

Answer 159

Excimer laser therapy is impractical, but it is particularly useful for localized areas, especially involving the hands.

Answer 160

PUVA therapy does not alter the incidence of basal cell carcinoma, despite reducing the risk of squamous cell carcinoma.

Answer 161

Patients should be advised to temporarily discontinue phototherapy until lesions resolve and then restart at a lower NB-UVB dose.

Answer 162

There are no studies evaluating the safety or efficacy of combined phototherapy with topical calcineurin inhibitors for atopic dermatitis in humans.

Answer 163

Relief of pruritus usually occurs within the first 2 weeks of NB-UVB therapy, prior to visible resolution of cutaneous lesions.

Answer 164

Due to the photosensitizing effect of tazarotene, it is recommended that PUVA therapy be initiated at slightly lower doses than usual.

Answer 165

While erythema is the most common side effect, other adverse reactions such as herpes simplex reactivation are rare.

Answer 166

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.

Answer 167

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.

Answer 168

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.

Answer 169

For patients not responding to standard therapies, excimer laser therapy may be particularly useful for localized areas, especially involving the hands.

Answer 170

RePUVA therapy can reduce the total cumulative UVA dose by more than one-half when combined with oral retinoids.

Answer 171

The timing of medication application, such as avoiding salicylic acid just before PUVA therapy, is crucial to ensure effective UVA penetration.

Answer 172

Improvements in atopic dermatitis can be maintained for months after stopping NB-UVB therapy, indicating its long-term benefits.

Answer 173

UVA1 phototherapy serves as a highly effective, nonsteroidal therapeutic alternative for managing acute exacerbations of atopic dermatitis.

Answer 174

The clinical significance of the combination of PUVA and oral therapies is not explicitly detailed in the provided text.

Answer 175

The combination enhances the efficacy of PUVA therapy, reducing the number of exposures and cumulative UVA dose while lowering the risk of SCC.

Answer 176

The two leading treatments for vitiligo are: 1. PUVA 2. NB-UVB

Answer 177

The earliest sign of response to NB-UVB therapy is **perifollicular repigmentation**.

Answer 178

Factors that predict how a patient will respond to NB-UVB include: - **Ethnic background** - **Skin phototype** - **The areas treated** - **The type of vitiligo**

Answer 179

NB-UVB therapy decreases **IL-17** and **IL-22** levels that are usually elevated in vitiligo.

Answer 180

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.

Answer 181

Clinical remissions for NB-UVB therapy in early stage CTC are reported to last for **3 to 24.5 months**.

Answer 182

NB-UVB therapy has a **more favorable safety and side effect profile** compared to PUVA, which is associated with more discomfort.

Answer 183

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.

Answer 184

1. **Clearing phase** 2. **Maintenance phase** 3. **Monitoring of therapy**

Answer 185

The earliest sign of response to the therapy is **perifollicular repigmentation**.

Answer 186

Factors that predict response include: - **Ethnic background** - **Skin phototype** - **The areas treated** - **The type of vitiligo**

Answer 187

NB-UVB therapy **decreases IL-17 and IL-22 levels** that are usually elevated in vitiligo.

Answer 188

Clinical remissions for NB-UVB therapy in early stage CTCL are reported to last for **3 to 24.5 months**.

Answer 189

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.

Answer 190

The text does not provide specific details on the potential risks associated with laser dermabrasion.

Answer 191

The potential risks include **pain**, **delayed wound healing**, and **hypertrophic scarring**.

Answer 192

Bathwater PUVA therapy with 8-MOP is a **valuable phototherapeutic alternative** for patients who cannot use systemic psoralens.

Answer 193

The combination of PUVA with interferon-2a or low-dose interferon-2b can lead to **prolonged remissions** in patients with tumor-stage CTC.

Answer 194

NB-UVB therapy helps to **restore the balance of oxidants and antioxidants**, relieving oxidative stress that plays a role in the pathogenesis of vitiligo.

Answer 195

NB-UVB therapy is administered **3 times per week**.

Answer 196

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.

Answer 197

Patients who show early initial repigmentation are more likely to achieve a **higher percentage of final repigmentation**.

Answer 198

Initial repigmentation is more likely to achieve a **higher percentage of final repigmentation**, indicating a better overall response to therapy.

Answer 199

Maintenance therapy in PUVA treatment for CTC is **not standardized** and requires **individualized schedules**, making it challenging to manage effectively.

Answer 200

Cream PUVA with 8-MOP can be considered for patients at **high risk of skin cancer**, providing targeted UV therapy.

Answer 201

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.

Answer 202

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.

Answer 203

This indicates that **combination therapy** may enhance the effectiveness of PUVA, especially in patients with tumor-stage CTC, leading to better treatment outcomes.

Answer 204

Afamelanotide, an analog of melanocyte-stimulating hormone, combined with NB-UVB may enhance treatment efficacy.

Answer 205

Further investigation is needed to determine its specific benefits.

Answer 206

The relapse rates for patients after one year of NB-UVB treatment range from **25% to 84%**.

Answer 207

Monitoring therapy is crucial to assess the effectiveness of treatment and to manage any potential relapses or side effects effectively.

Answer 208

Skin phototype is one of the factors that can predict how well a patient will respond to NB-UVB therapy, influencing treatment outcomes.

Answer 209

This highlights the need for careful patient management and consideration of pain management strategies when using NB-UVB therapy.

Answer 210

NB-UVB therapy **increases FoxP3-expressing cells**, which helps restore the balance between Th17 and regulatory T cells in vitiligo patients.

Answer 211

This indicates that certain areas of the body may require alternative treatment strategies, as they do not respond well to standard combination therapies.

Answer 212

Using NB-UVB therapy in combination with topical steroids is expected to be significantly effective.

Answer 213

Topical steroids are expected to be significantly more effective than using either treatment alone.

Answer 214

Palliative treatment aims to **reduce the tumor-cell burden** and act synergistically with other treatments to improve patient quality of life.

Answer 215

This suggests that ongoing maintenance therapy is important for sustaining treatment benefits and preventing relapse in patients receiving NB-UVB therapy.

Answer 216

This indicates that patients with advanced CTCL may require **permanent maintenance treatment** to manage their condition effectively.

Answer 217

The expected outcome is **prolonged remissions** in patients with tumor-stage CTCL, enhancing the effectiveness of treatment.

Answer 218

Individualized schedules are important to tailor treatment to each patient's specific needs and responses, optimizing therapeutic outcomes.

Answer 219

Targeted phototherapy with a 308-nm excimer laser is considered **first-line therapy** for localized vitiligo. It is effective in achieving repigmentation.

Answer 220

2 to 3 times weekly.

Answer 221

The total number of sessions rather than the frequency of treatments.

Answer 222

It can deliver higher energy exclusively to affected areas while minimizing side effects.

Answer 223

It can decrease lesional skin thickness, improve skin elasticity, reduce sclerotic plaques, and increase passive range of motion.

Answer 224

60 to 130 J/cm² five times per week, with lower doses also being effective.

Answer 225

Treatment effectiveness.

Answer 226

It has been employed in children and adults with graft versus host disease who are resistant to or have relapsed on standard immunosuppressive regimens.

Answer 227

Regularly examine these patients due to their increased risk of skin cancer from immunosuppressive therapies.

Answer 228

Oral PUVA and UVA1, indicating a multi-faceted approach to managing this condition.

Answer 229

UVB phototherapy is an effective option for treating pruritus.

Answer 230

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**.

Answer 231

2 to 3 times weekly.

Answer 232

The excimer laser achieves the same grade of repigmentation as NB-UVB but at a lower total cumulative dose.

Answer 233

Combining a topical antioxidant gel with the excimer laser appears to have higher efficacy in terms of repigmentation.

Answer 234

UVA1 decreases lesional skin thickness, improves skin elasticity, reduces sclerotic plaques, and increases passive range of motion.

Answer 235

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.

Answer 236

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.

Answer 237

Medium dose and less-frequent treatments would be more effective.

Answer 238

UVA1 works partly through induction of MMP-1 and downregulation of transforming growth factor via the SMAD signaling pathway, which correlates with clinical improvement.

Answer 239

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.

Answer 240

UVA1 has led to modest improvement in the degree of induration and in mobility of the hands and legs.

Answer 241

Approximately 80% to 90% of patients improve within 2 to 5 weeks of phototherapy.

Answer 242

BB-UVB exposure to one-half of the body improves pruritus in both the exposed and unexposed sites, indicating a systemic effect.

Answer 243

Phototherapy is considered by some to be the most effective treatment for cholestatic pruritus.

Answer 244

PUVA has shown improvement in aquagenic pruritus in several patients, but maintenance treatments may be required.

Answer 245

Oral PUVA has been used to treat disabling, extensive morphea in children.

Answer 246

UVA1 has been used to treat acral scleroderma in patients with systemic scleroderma, leading to improvement in skin softening and increased finger movement.

Answer 247

The recurrence after successful UVA1 treatment was dependent on the duration of morphea prior to treatment, rather than morphea subtypes or Fitzpatrick skin type.

Answer 248

Combining PUVA with medium-potency topical corticosteroids is 3 times more effective than either treatment alone.

Answer 249

Oral and topical PUVA have been used for systemic scleroderma, with improvement in range of motion and contractures.

Answer 250

It is important to examine the patients regularly, as they have an increased risk of skin cancer from their immunosuppressive therapies.

Answer 251

Higher doses of UVA1 may cause tanning responses that interfere with treatment efficacy, suggesting a need for careful dose management.

Answer 252

The monochromatic excimer laser can deliver higher energy exclusively to affected areas while minimizing side effects, making it effective.

Answer 253

UVA1 is effective for vitiligo as it targets affected areas while minimizing side effects.

Answer 254

The ultimate rate of repigmentation is dependent on the total number of sessions rather than the frequency of treatments.

Answer 255

UVA1 does not cause repigmentation but accentuates the color difference by tanning the normal skin.

Answer 256

Medium dose and less-frequent treatments are recommended for better efficacy in softening sclerodermatous patches.

Answer 257

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.

Answer 258

Phototherapy is an effective option for pruritus associated with chronic renal failure, with a high response rate in patients.

Answer 259

UVB phototherapy has been combined with cholestryramine to enhance treatment efficacy for cholestatic pruritus.

Answer 260

UVA1 treatment has shown improvement in softening affected skin and increasing finger movement in patients with acral sclerosis.

Answer 261

NBUVB monotherapy shows significant improvement especially in patients with Fitzpatrick skin types IV through VI.

Answer 262

Regular follow-up is crucial due to the increased risk of skin cancer from immunosuppressive therapies in these patients.

Answer 263

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.

Answer 264

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.

Answer 265

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.

Answer 266

For chronic hand eczema, NBUVB and local baths are recommended.

Answer 267

Narrowband UVB (NB-UVB) and local bath PUVA are successful treatments.

Answer 268

Oral PUVA is preferred for hyperkeratotic eczema.

Answer 269

Bath PUVA is more beneficial for dyshidrotic eczema.

Answer 270

Localized UVA1 has similar efficacy to cream PUVA for chronic vesicular dyshidrotic eczema.

Answer 271

Determining the minimal urticarial dose is crucial as it helps to initiate treatment at a dose lower than this threshold to minimize exacerbations.

Answer 272

NB-UVB is considered effective and well-tolerated in patients with chronic urticaria who have failed first-line antihistamine regimens.

Answer 273

NB-UVB may have greater penetration into the dermis and larger systemic immunosuppressive effects compared to BB-UVB, which has a higher relapse rate.

Answer 274

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.

Answer 275

PUVA therapy offers rapid and intense pigment induction at relatively low UVA doses.

Answer 276

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.

Answer 277

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.

Answer 278

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.

Answer 279

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.

Answer 280

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.

Answer 281

PUVA therapy has been reported to induce lichen planus and lichen planus pemphigoides in patients undergoing treatment for other skin conditions.

Answer 282

There is a potential risk of exacerbating or triggering these conditions.

Answer 283

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.

Answer 284

NB-UVB therapy is typically administered 3 times per week on nonconsecutive days for patients with lichen planus.

Answer 285

NB-UVB is effective for both conditions: ## Footnote - 65% complete response for pityriasis lichenoides et varioliformis acuta - More than 85% complete response for pityriasis lichenoides chronic.

Answer 286

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.

Answer 287

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.

Answer 288

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.

Answer 289

It relieves pruritus and decreases urinary histamine levels.

Answer 290

Serum tryptase levels trended downward during PUVA therapy, suggesting it may be used as a surrogate marker for response in some patients.

Answer 291

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.

Answer 292

The mechanism of action of PUVA in granuloma annulare is unclear, but selective elimination of pathogenic cells may be one explanation.

Answer 293

The recommended first-line therapy for chronic plaque psoriasis is NB-UVB.

Answer 294

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.

Answer 295

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.

Answer 296

Oral PUVA is reserved for patients with telangiectasia macularis eruptiva due to specific treatment considerations.

Answer 297

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.

Answer 298

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.

Answer 299

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.

Answer 300

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.

Answer 301

The mechanism of action of PUVA in granuloma annulare is unclear, but selective elimination of pathogenic cells may be one explanation for its effectiveness.

Answer 302

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.

Answer 303

The first-line therapy for chronic plaque psoriasis is NB-UVB.

Answer 304

The treatment for chronic plaque psoriasis is NB-UVB.

Answer 305

Long-term methotrexate use, defined as 36 or more months, in combination with PUVA may increase the risk of lymphoma.

Answer 306

In vitiligo, the earliest sign of response to therapy is perifollicular repigmentation, indicating the effectiveness of the treatment.

Answer 307

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.

Answer 308

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.

Answer 309

Phototherapy stabilizes mast cell membranes, decreases histamine release, and induces mast cell apoptosis.

Answer 310

Phototherapy increases reactive oxygen species (ROS), IL-1, IL-6, and MMP-1, leading to collagen degradation.

Answer 311

Phototherapy causes acanthosis, thickening of the stratum corneum, and stimulates cytokeratins 15 and 10.

Answer 312

Phototherapy stimulates melanogenesis.

Answer 313

Melanocytes are cells that produce melanin, contributing to skin pigmentation.

Answer 314

Phototherapy stimulates melanogenesis and contributes to skin repigmentation.

Answer 315

Phototherapy is effective in atopic dermatitis, psoriasis, lichen planus, and cutaneous T-cell lymphoma.

Answer 316

Phototherapy is effective in mast cell-mediated diseases, sclerotic skin diseases, and some photodermatoses.

Answer 317

Phototherapy increases IL-10, cyclooxygenase-2, and prostaglandin E2, while decreasing dendritic cell activity and promoting T-cell apoptosis in lymphoid infiltrates.

Answer 318

Phototherapy stabilizes mast cell membranes, decreases histamine release, and induces mast cell apoptosis, influencing allergic responses and inflammation.

Answer 319

Phototherapy increases reactive oxygen species (ROS), IL-1, IL-6, and MMP-1, leading to collagen degradation and potential skin remodeling effects.

Answer 320

Phototherapy stimulates keratinocytes, leading to acanthosis, thickening of the stratum corneum, skin 'hardening', and repigmentation.

Answer 321

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.