| • | classic distribution = dorsum of hands and face |
| • | always at least think of photo, when face is involved |
the five "P's" and connective tissue disease (it rhymes)
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pearl: tinea faceii can be "photosensitive" (often mistaken for LE or rosacea)
The photosensitivity work-up:
| • | check meds |
| • | labs – ANA, Ro, La, porphyrins |
| • | good porphyria screen = plasma levels: will be elevated in almost all porphyrias (if positive, can then check RBC, stool, urine) |
phototesting:
| • | chronic actinic dermatitis: UVB sensitive |
| • | photocontact and photo drug: UVA (except topical benadryl = UVB ) |
| • | porphyria: visible light |
history:
| • | only solar urticaria, EPP, and some drug photosensitivity has onset in 5 or 10 minutes and resolution over hour |
| • | PMLE typically “hardens” by summers end (and it re-occurs each year in spring or summer) |
SUMMARY/QUIZ:
Morphology = (guess the disease):
pruritic wheals solar urticaria
painful burning sensation with no visible signs (initially) EPP
blistering always leads to varioliforme scarring hydroa vacciniforme
| fragility or blistering with scarring PCT or pseudo-PCT (ddx also includes EBA, though it is acral rather than “photo-distributed”) |
| eczematous eruption accentuated or limited to exposed sites CAD vs. light aggravated endogenous eczema |
lack of pruritis and presence of discrete scaling plaques SCLE (vs. PMLE)
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Onset: |
Morphology: |
Age of Onset: |
Treatment: (sunscreen plus…) |
PMLE |
hours to days |
polymorphic |
young women |
PUVA, aminoquinilones |
Actinic Prurigo
(excoriated PMLE) |
hours to days |
excoriations, eczematization |
young girls (resolves in adolescence) |
low dose thalidomide (= drug of choice) |
Hydroa Vacciniforme
(scarring PMLE) |
hours to days |
scarring papulovesicles |
children (resolves in adolescence) |
Beta-carotene, anti-malarials |
Solar Urticaria |
minutes |
pruritic wheals |
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non-sedating H1 antihistamines |
EPP |
minutes |
burning |
childhood |
Beta-carotene |
SCLE |
hours to days |
psoriasiform plaques |
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stop the offending drug; |
CAD |
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eczematous |
elderly |
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