Dermatology

Question 1

What are the 3 types of porphyria? How to diagnose?

Answer 1

1. Porphyria cutanea tarda - inhibition of 5th enzyme in heme bio synthetic pathway - uroporphyrinogen decarboxylase. Associated with haemochromatosis, hepatitis C, hiv, alcohol, tobacco, oestrogen. Shows painless blistering lesions in sun exposed areas. Has brownish red urine - shows elevated urine or plasma porphyrin for diagnosis. Treat the modifiable risk factor and iron chelation or hydroxychloroquine.
2. Acute intermittent porphyria - autosomal dominant, 3rd enzyme, porphobilinogen delaminate. Usually female, aged 18-45z has abdo pain, vomiting, afebrile tachy, weakness dysthesia, seizures. Supportive treatment and anticonvulsants. Cannot use phenytoin, valproate, carbamazepine, clonazepam. Intravenous heme is treamtent.
3. Protoporphyria - BM overproduction of protoporphyrin. Usually in childhood, stinging oedema of sun exposed skin. Can treat with oral beta carotene but only works in <1/3 of cases,