JAAD Possible Questions Flashcards
What is the spectrum for visible light
400-700
UVR range
10-400 nm
Red and blue light spectrums and which penetrate the skin deeper
Red 625-700
Blue 400-500
Red penetrates the full thickness of skin
What % of VL is reflected by skin surface
4-7
Which has higher energy - blue or red light
Blue light
How far does RL and BL penetrate
RL is 6-50 nm
BL 0.5 - 1 mm
Epidermal thickness
30-100 um
Epidermal and derma thickness
0.5-6 mm
VL is implicated in what photodermatoses commonly
Solar urticaria
Cutaneous porphyria (makes sense Soret band)
Less commonly PMLE and CAD
PMLE - what light is commonly implicated
UVA alone most commonly
But UVB and uncommonly VL can xause
CAD - which light is associated with severe exacerbation
UVB the worst
Mostly UVB UVA and rarely VL
What are the UV ranges
UVB 290-320 UVA2 320-340 UVA1 340-400 VL 400-700 IR 700- mm
5 main types of organic filters (chemical filters)
PABA Benzophenones Salicylates Cinnamates Other
What part of sunscreen protects against visible light
Tinted sunscreens: blends of iron oxides and titanium oxygen pigment
Because the chemical and physical blockers dont cover visible light
What does broad spectrum sunscreen mean
> 370 nm
At least 90% of the products total absórbance must be at or above this wavelength when measured using UV wavelengths ranging from 290-400 nm
What does SPF measure
Erythemogenic effect of UVB and a lesser extent UVA2
For this - 2 mg/cm^2 applied working out to be 30 mL for the entire body surface
Why does oxybenzone suck
It is the most common sunscreen allergen
If bleached coral
What are some non topical forms of photprotection
Polypodium leucotomas extract - ? For melasma
Nicotinamide
Afámelanotide: analogue of alpha melanocyte stimulating hormone. Approved for EPP
