Sun Health Flashcards
What are some characteristics of UVA?
“tanning rays”
photo reactions
What are some characteristics of UVB?
“burning rays”
vit D production
Which UV radiation is cancer causing?
UVC
How many new cases of skin cancer are there per year?
> 80 000
9000 will be melanoma, 1200 die
What is actinic keratosis?
skin condition by UV radiation
considered a precancer
occurs on sun-exposed parts of the body
rough, dry, scaly patches
What is the most common form of skin cancer?
basal cell carcinoma
-occurs on sun exposed parts of the body
What is the second most common skin cancer?
squamous cell carcinoma
-starts in epidermis, penetrates underlying tissue if not
treated
-occurs on sun exposed areas
-wart-like growth that crusts, red patch, elevated
What is the strategy used to identify melanoma?
ABCD
asymmetry
border (uneven edges)
color (various shades)
diameter (larger than 6mm)
What are phototoxic reactions?
drug becomes activated by sunlight
appears like a sunburn
fast onset (generally acute)
clears once the drug is discontinued
dose of drug matters (more is worse)
What are photoallergic reactions?
sun changes structure of drug and now drug is seen as an antigen
resembles eczema
takes 1-2 days to appear (chronic)
can move to unexposed skin
mainly topical drugs
dose of agent can be very small
Which drugs are phototoxic?
sulfas
tetracycline
NSAIDs
retinoids
What is an example of a photo-aggravated disorder?
rosacea
Which disorder is helped by sunlight?
psoriasis
True or false: UVB can reflect off of the sand or water
false
UVA can do that
What does SPF stand for?
sun protection factor
True or false: almost all sunscreens are broad-spectrum
true
Whats a reasonable strength of sunscreen?
30
anything higher is only micro-advancements
What does the SPF number tell you?
how long UV radiation would take to redden your skin when using the product vs the amount of time without any sunscreen
ex: SPF 30 means it would take 30x longer to burn than
without the sunscreen
What is an example of a sunscreen that works physically?
zinc oxide
Ideally how far in advance should we apply sunscreen before sun exposure? How often should it be re-applied?
30 minutes
Q2hrs
What is the official age for sunscreen use?
> 6 months
Which agent reduces the effectiveness of sunscreen?
DEET
Which agents have been promoted as tanning products?
beta carotene
canthaxanthin
dihydroxyacetone (DHA)
-pigmenting agent
-no SPF value
-reapply Q 2 days
What happens when you discontinue dihydroxyacetone?
color dissipates in 2 weeks
What is the most important thing you can do for sunburn? What are some other things you could do?
cool compress
others: dry skin lotion, aloe, lidocaine, voltaren, steroid
What are the de-pigmenting agents?
hydroquinone (Rx 5%, cosmetics 2%)
monobenzone (Rx only, more potent)
Describe characteristics of melasma.
appearance: brown patches on face, mainly women
cause: hormonal change? pregnancy? birth control pills?
sun exposure? (exact cause=unknown)
treatment: no cure, sunscreen can control it, hydroquinone
Describe characteristics of tinea versicolor.
appearance: uneven skin colour, scaling, white-to-pink or tan-
to-dark spots, more noticeable when tanned,
mainly teens or young adults
cause: fungus
treatment: anti-fungals
Describe characteristics of vitiligo.
appearance: loss of pigment in patches, any body part, milky-
white skin
cause: autoimmune (most ppl are in good health)
treatment: often none, avoid tanning, SPF for white patches,
disguising with makeup, DHA, tattoos
In terms of basal cell carcinoma, squamous cell carcinoma, and melanoma. Which is the worst?
melanoma
BCC<SCC<melanoma
If the minimal erythema dose protected was 40min and the minimal erythema dose unprotected was 10min, what is the SPF?
4
What is a classic spot that is often forgotten about when applying sunscreen?
ears
