Porphyrias Flashcards
what are the three most common porphyria
1 - Porphyria cutanea tarda (PCT)
2 - Erythropoietic protoporphyria (EPP)
3 - Variegate porphyria
what are the different types of porphyria
- phototoxic skin porphyria
- blistering and fragility skin porphyria
- acute attack porphyria
- severe congenital porphyria
what enzyme is affected in PCT
Uroporphyrinogen decarboxylas
what is the typical presentation of PCT
blisters, fragility on hands and scalp hyperpigmentation hypertrichosis (excessive hair growth) solar urticaria morphoea (localized scleroderma)
what can happen to the skin in PCT on chest
tightens causing nipples to move closer
what investigations are done if PCT is suspected
Woods lamp
what is the general Mx for PCT
find underlying cause and treat that
what are causes of PCT
Alcohol
Viral hepatitis
Oestrogens
Haemochromatosis
what is the cause of EPP
build up of protoporphyin IX
what enzyme is defect in EPP
ferrochelatase
when do first signs of EPP occur
infancy or early childhood
what are the first signs of EPP
uncomfortable/painful burning sensation after sun exposure
what areas are commonly affected in EPP
tops of hands and feet, face, ears
what can happen to affected skin in EPP
become red, swollen and blister
pitted scars
crust, thickened skin
what investigations are done if EPP suspected
Quantitative RBC porphyrins
Fluorocytes
Transaminases
