Porphyrias Flashcards
Basic biochemistry of pathway that if is a defect/defiency in is a porphyria = ___-> ___
glycine and succinyl-CoA —> Haem
4 main groups of porphyrias
phototoxic skin porphyrias
blistering and skin fragility
acute attack (may have no skin involvement)
severe congenital porphyrias
an example of a phototoxic skin porphyria =
erythropoetic protoporphyria (EPP)
uroporphyrinogen decarboxylase (UROD) deficiency =
Porphyria cutanea tarda (PCT) type 1
2 typical features of porphyria presentation
blistering
skin fragility
Wood’s lamp is to investigate
fungal and bacterial infections
pigment conditions eg. vitiligo, PCT, EPP, ECP
underlying causes of PCT can be
alcohol, viral hepatitis, oestrogens and haemochromatosis
ferrochelatase deficiency that means protoporphyrin IX isnt converted to ___ =
EPP (erythopoeitic porphyria)
haem
EPP usually presents in ___ with ___
childhood
acute photosensitivity of the skin (pruritis, erythem, swelling, pain)
PBG deaminase deficiency =
causes PBG not to be converted to ___
acute intermittent porphyria
hydroxymethylbilane
Investigations for porphyrias
Wood's Lamp quantitive RBC porphyrins fluorocytes transaminases [Hb] red cell indices biliary tract US
management of porphyrias
6mnthly LFTs and RBC porphyrins visible light photprotection - sunscreens phototherapy avoid iron antioxidants prevent liver failure
