Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Dermatology > Photodermatology > Flashcards

Photodermatology Flashcards

You may prefer our related Brainscape-certified flashcards:
Dermatology Board Prep flashcards
1
Q

define photodermatology

A

the study of the interaction between non-ionising radiation and the skin

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

list some benefits of UV exposure

A 
photosynthesis 
vit D synthesis 
heat
circadian rhythm 
bactericidal 
therapeutic and diagnostic uses 
vision
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

list some hazards of UV exposure

A 
sunburn 
eyes - conjunctivitis, keratitis, cataracts
photageing 
skin cancer
photosensitivity - photodermatoses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What bands of UV radiation pass through the ozone layer, and what bands are completely absorbed by the ozone layer

A

UVC - all absorbed by the ozone layer
UVB - some absorbed by the ozone layer
UVA - a little absorbed by the ozone layer

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

What UVR bands are we exposed to on earth

A

mainly UVA

some UVB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What UVR band is most likely to cause sunburn - UVA or UVB and why

A

UVB - it is most active

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

What band of UVR do sunbeds use

A

Fluorescent UVA

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

What band of UVR is used in phototherapy

A

narrow band UVB

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

In what conditions is UVA phototherapy used to treat

A

this is a new development for eczema, skin scleroderma

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

What is photochemotherapy

A

aka PUVA = psoralen + UVA

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

what is the role of psoralen

A

sensitises the skin to UVA

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

What is used 1st line in therapeutic UVR: UVB phototherapy or photochemotherapy?

A

UVB phototherapy

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

why is UVA Tx used second line to UVB phototherapy

A

with UVA there is an increased risk of skin cancer

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

How many Fitzpatrick skin types are there

A

six

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Type I Fitzpatrick skin type

A

only burns

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

Type II Fitzpatrick skin type

A

always burns, can tan

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

Type III Fitzpatrick skin type

A

tans, can burn

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

Type IV Fitzpatrick skin type

A

tans

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

Type V Fitzpatrick skin type

A

dark brown skin

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

Type VI Fitzpatrick skin type

A

black skin

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

What happens to cells in the epidermis when someone is sunburned

A

apoptosis of keratinocytes

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

Typical duration of onset of UVB “sunburn” erythema

A

2-4h, peak 12-24h

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

Typical duration of onset of PUVA erythema

A

onset 24h, peak 96h

24
Q

Mediators of UVB erythema

A

prostaglandins

25
Q

Mediators of UVA erythema

A

oxygen

26
Q

effect of sunlight on the immune system

A

causes immunosuppression

27
Q

how does sunlight cause immunosuppression

A

langerhan’s cell migrate from the BM to draining lymph nodes, and there is suppression of delayed hypersensitivity

28
Q

why is sunlight causing a suppression of delayed hypersensitivity particularly important?

A

important in the promotion of carcinogenesis

29
Q

what is photoageing also called?

A

solar elastosis

30
Q

list the 4 different categories of photodermatoses

A
  1. Immunological/Idiopathic
  2. Genetic
  3. Chemical photosensitivity
  4. Photoaggravated dermatoses
31
Q

List the different IMMUNOLOGICAL/IDIOPATHIC photodermatoses

A
  • polymorphic light eruption
  • actinic prurigo
  • solar urticaria
  • chronic actinic dermatitis
  • hydroa vacciniforme
32
Q

what is a polymorphic light eruption (PLE)

A

after a few hours of sun exposure, papules and vesicles develop, which resolve after a few days without scarring

33
Q

what type of hypersensitivity reaction is PLE

A

Type IV

34
Q

Tx of PLE

A

watch and wait - will resolve

UVB desensitisation (90% effective)

35
Q

Ix for PLE

A

UVA provocation test

36
Q

what is actinic prurigo

A

an idiopathic photodermatoses, that occurs in childhood (1st decade) with sore and red papules on the eyes, lips, end of nose that scars

37
Q

what antigen is associated with actinic prurigo

A

HLA DR4

38
Q

what is solar urticaria

A

an idiopathic photodermatoses that occurs within a few minutes of sun exposure.

39
Q

what type of hypersensitivity reaction is solar urticaria

A

type I

40
Q

Tx of solar urticaria

A

antihistamines

desensitisation

41
Q

what is chronic actinic dermatitis

A

an idiopathic photodermatoses that is essentially pho-exposed site eczema

42
Q

what type of hypersensitivity is chronic actinic dermatitis

A

type IV

43
Q

what bands of UVR is the person sensitive to in chronic actinic dermatitis

A

broadband - UVA, UVB and visible light

44
Q

who usually gets chronic actinic dermatitis

A

old men

45
Q

list the different GENETIC photodermatoses

A

xeroderma pigmentosum (the only one we need to know)

46
Q

what is xeroderma pigmentosum

A

autosomal recessive disease

- failure of DNA excision repair

47
Q

presentation of xeroderma pigmentosum

A

rapid photoageing of the skin and skin cancer

death in teen

48
Q

what type of skin cancer do people with xeroderma pigmentosum get

A

both melanoma and non-melanoma

49
Q

list the different CHEMICAL photodermatoses

A

exogenous - drugs

endogenous - porphyrias

50
Q

list the different drugs can induce photosensitivity

A

psoralens e.g. lime, celery

antibiotics

  • sulphonamides
  • tetracyclines
  • fluroquinolones

diuretics

  • thiazides
  • furosemide

NSAIDS

Quinine

Amiodarone

51
Q

What is phytophotodermatosis

A

a condition in children where they have been exposed to psoralens, then exposed to UVA light

52
Q

What can phytophotodermatosis be confused with

A

Non-accidental injury

53
Q

What is a photoaggravated dermatoses

A

a pre-existing skin disease that is aggravated by sunlight

54
Q

List the different PHOTOAGGRAVATED dermatoses

A 
eczema
psoriasis
rosacea 
pemphigus, pemphigoid 
erythema multiforme
55
Q

What are the mainstay investigations for photodermatoses

A 
monochromator phototesting 
UVA provocation test 
MED test (minimal erythema dose test) 
patch tests 
HLA status 
histology

(Depends on individual presentation)

Dermatology (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions