Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

FD9 > 198 - Phototherapy > Flashcards

198 - Phototherapy Flashcards

1
Q

Most common short term adverse effect of phototherapy

A

Sunburn-like reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

UVB phototoxicity usually peaks at _____

PUVA reaction manifests at _____

A

12-24 hours

24-48 or even 72 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Long term follow up studies established an increased risk of _____ (3) for PUVA therapy

A

Lentigines
Squamous cell carcinoma
Possibly melanoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

UVB wavelength

A

290-320 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

UVB radiation types of DNA damage (4)

A
  1. Formation of pyrimidine dimers and 6,4-pyrimidine-pyrimidone photoproducts
  2. Conversion of trans- to cis-urocanic acid
  3. Conversion of tryptophan into 6-formylindololo[3,2-b]carbazole
  4. Generation of reactive oxygen intermediates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Breakdown product of histidine; present in large amounts in stratum corneum

A

Urocanic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Effect of cis-urocanic acid

A

Mediator of UVB-induced immunosuppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Increase in hydroxyvitamin D synthesis inversely correlates with baseline levels of

A

Trans-urocaninc acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

UVA wavelength

A

320-400 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Depth of penetration:

  1. UVA
  2. UVB
A
  1. Mid- or lower dermis (140 microns)

2. Epidermis and superficial dermis (14 microns)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Major biologic effects of UVA radiation are from

A

Generation of reactive oxygen intermediates in mitochondrial enzyme complexes during oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

UVA1 wavelength

A

340-400 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

UVA1 has immunoprotective properties via

A

Generation of heme oxygenase-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Major photochemical effect of psoralen photochemotherapy

A

Damage to DNA

  1. Intercalate with DNA
  2. Production of reactive oxygen intermediates such as singlet oxygen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Have 2 double bonds that can absorb UVA radiation

A

Psoralens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

UVB effect on:

  1. Effector T cells
  2. Regulatory T cells
A

Inhibits activation of effector T cells

Leaves the development of regulatory T cells unaltered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Major function of dendritic cells

A

Present antigen to T-lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Disruption of activities of dendritic cells through (2)

A

Direct effects of UVB

Indirectly through production of IL-10 and prostaglandin E2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

UV exposure significantly lowers levels of immunomodulatory factors such as _____, possibly reflecting a loss of Langerhans cells

A

Prostaglandin D2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Effect of phototherapy in cutaneous lymphoid infiltrates

A

Cell death by apoptosis of T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Effect of phototherapy on expression of CD54 and other adhesion molecules

A

Decreased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Facilitates T-cell binding to keratinocytes through its interaction with lymphocyte function-associated antigen-1 that is present on T cells; not normally present on epidermal keratinocytes

A

Intercellular adhesion molecule-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Effects on immune system provide an explanation for phototherapy’s efficacy in cutaneous diseases in which T-cell hyperactivity predominates such as

A

Psoriasis
Atopic dermatitis
Lichen planus
Cutaneous T-cell lymphoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Phototherapy for treatment of mast-cell mediated diseases

A

PUVA

UVA-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
PUVA vs UVA1 effects on mast cells
PUVA - stabilize mast cell membranes | UVA1 - apoptosis of mast cells
26
Phototherapy for treatment of sclerotic skin diseases
PUVA | UVA-1
27
UVA downstream effect on collagen
Activation of matrix metalloproteinase-1 resulting in degradation of collagen
28
UVA increases the production of _____ (2) which are stimuli for MMPs
IL-1 | IL-6
29
Effect of phototherapy on the epidermis
Acanthosis | Thickening of the stratum corneum
30
Effect of phototherapy on keratinocytes has been exploited for the management of
Chronic photosensitivity disorders
31
Phototherapy stimulatory effects on melanogenesis (decrease/increase) the efficacy of phototherapy
Decrease
32
Markers for stem cell activation in the follicular and interfollicular epithelium
Cytokeratins 15 and 19
33
Phototherapy devices generate light by the conversion of _____ energy into _____ energy
Electrical | Electromagnetic
34
Generate UVR by passing electric current though a thin tungsten filament, which, in turn, generates heat and light
Incandescent lamps
35
Tungsten filament is sealed in a quartz envelope that contains a halogen (bromide or iodine)
Quartz halogen lamps
36
These lamps can emit wavelengths within the UV, visible, and infrared ranges
Quartz halogen lamps
37
Used in situations that require visible light such as phototesting and photodynamic therapy
Incandescent lamps/quartz halogen lamps
38
When a high voltage is passed across 2 electrodes in the presence of a gas, the electrons of the gas become excited. When the gas electrons return to their ground state, light is emitted.
Arc or gas discharge lamps
39
Example of a metal halide lamp
UVA1
40
High-pressure arc lamps typically contain _____ or _____, whereas low-pressure arc lamps use _____.
Mercury, xenon gas | Fluorescent material
41
Broadening of spectral output of discharge lamps done through (2)
Altering the gas pressure | Addition of metal halides
42
Most commonly used sources of therapeutic UVR
Fluorescent lamps
43
Chemicals called phosphors/fluorophores absorb and then reemit light. The light that is reemitted is of lower energy (and thus longer wavelength)
Fluorescent lamps
44
Examples of fluorescent lamps
311 nm NB-UVB | Broadband UVB and UVA
45
UVB combined with the topical application of coal tar as treatment for psoriasis
Goeckerman therapy
46
Approximately two-thirds of the output is in the UVB range and the rest is primarily in the UVA
BB-UVB
47
Wavelengths that most efficiently clear psoriasis
Approximately around 313 nm
48
Wavelengths most efficient at causing erythema and nonmelanoma skin cancer
Less than 300 nm
49
NB-UVB light sources emit only wavelengths between
308 and 313 nm
50
Initial starting dose of BB-UVB and NB-UVB is determined through (2)
Minimal erythema dose | Empirically based on Fitzpatrick skin type
51
MED is determined by exposing six 1-cm2 areas of skin on the _____ or _____
Inner aspect of the forearm | Lower back
52
MED reading after _____ hours for NB-UVB
24
53
Phototherapy is initiated at _____% of the smallest UV dose that results in uniform erythema over the entire area
50-70
54
Maximum NB-UVB dose
2000-5000 mJ/cm2
55
8-methoxypsoralen preparations
Micronized form | Dissolved form
56
8-MOP micronized form administration
0.6 mg/kg 120 minutes prior
57
8-MOP dissolved form administration
0.4 to 0.6 mg/kg 90 minutes prior
58
More commonly employed preparation of 8-MOP
Dissolved
59
Micronized vs dissolved form of 8-MOP
Dissolved preparation: Absorbed faster Yields higher and more reproducible serum levels
60
MPD (minimum phototoxic dose) reading after _____ hours for oral UVA
72
61
Benefits of bath PUVA vs oral
Circumvents GI side effects and possible phototoxic hazards to the eyes
62
Initial exposure dose for NB-UVB and oral PUVA
50-70% of MED/MPD
63
Initial exposure dose for bath PUVA
30% of MPD
64
Tolerance is rapidly lost when exposures cease, requiring downward adjustments of dose after as little as _____ week to avoid burns
1
65
More than _____ BB-UVB treatments is associated with a modest, but significant, increase in squamous cell carcinoma and basal cell carcinoma
300
66
Carcinogenic risk of a single PUVA treatment is approximately _____ times greater than a single UVB treatment
7
67
8-MOP acute side effects
Nausea and vomiting
68
8-MOP acute side effects more common with which preparation?
Liquid
69
Contraindicated in individuals who have been treated with PUVA
Cyclosporine
70
_____ used concurrently with PUVA reduce the risk of SCC
Oral retinoids
71
Relative contraindication for further PUVA therapy
Personal or family history of melanoma | History of more than 200 PUVA treatments
72
Recommended first-line therapeutic agents for moderate to severe psoriasis in HIV-positive patients
Phototherapy and antiretrovirals
73
NB-UVB dose associated with decrease in serum folic acid levels
>118.16 J/cm2 in 36 treatments
74
BB-UVB dose associated with decrease in serum folic acid levels
110-220 mJ/cm2 in 7-22 treatments
75
Special considerations regarding phototherapy in elderly
Erythema lasts longer and peaks later | Photoadaptation may be decreased
76
First line therapy (phototherapy) for chronic plaque psoriasis
NB-UVB
77
Application of calcipotriol prior to phototherapy leads to _____ (2)
Unwanted degradation of vitamin D3 | Increases MED
78
Topical medication that should not be used during phototherapy because it blocks UVB penetration
Salicylic acid
79
Polymorphism in genes encoding _____ are associated with PUVA sensitivity
Glutathione S-transferases
80
Long-term methotrexate, defined as 36 or more months of use, in combination with PUVA may increase the risk of
Lymphoma
81
Should not be applied within 2 hours of phototherapy
Calcipotriol
82
UVA1 is a therapeutic alternative for treatment of acute exacerbations of
Atopic dermatitis
83
Earliest sign of response to phototherapy in vitiligo
Perifollicular repigmentation
84
Cosmetically acceptable treatment success in vitiligo is defined as
Greater than or equal to 75% repigmentation
85
First-line phototherapy in localized vitiligo
308-nm excimer laser
86
Type of phototherapy that does not cause repigmentation
UVA1
87
Recurrence after successful UVA1 treatment of morphea was dependent on
Duration of morphea prior to treatment
88
Phototherapy for photodermatoses typically initiated
1 month before the anticipated intense sun exposure
89
Type of phototherapy not particularly effective in preventing solar or other forms of urticaria
UVA1
90
_____ PUVA is preferable for patients with hyperkeratotic eczema and _____ PUVA is more beneficial for dyshidrotic eczema
Oral | Bath

FD9 (108 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions