porphyrias Flashcards
what is porphyrias
group of diseases in which substances called porphyrins build up negatively affecting the skin or nervous system
what is the most common porphyrin
haem
what are the general symptoms of porphyrias
acute phytotoxicity
blistering
skin fragility
what is the treatment of porphyrias
behavioural avoidance clothing sunscreen hardening the skin (PUVA) chromophore removal
what is Normal cutaneous photosensitivity
sunburn
what is used to classify response to sunlight
Fitzpatrick scale
where would white, freckled skin be on the Fitzpatrick scale
type 1
where would deep black skin be on the Fitzpatrick scale
type 6
what causes Erythopoietic protoporhyria (EPP)
deficiency in ferrochelatase
what type of mutation causes Erythopoietic protoporhyria (EPP)
X-linked dominant
what are the symptoms of Erythopoietic protoporhyria (EPP)
acute photosensitivity swelling pain mild anaemia hepatobiliary disease (gallstones, liver failure)
what can repeated exposure to the sun in Erythopoietic protoporhyria (EPP) cause
scarring
hyper or hypo-pigmentation
lichenification
what is the treatment of Erythopoietic protoporhyria (EPP)
spectrophotometer
quantitative RBC porphyrins
fluorocytes
transaminases
what is the treatment of Erythopoietic protoporhyria (EPP)
genetic counselling LFTs and RBC porphyrins every 6 months photo-protection measures UVB phototherapy anti-oxidants iron avoidance
what is Porphyria cutanea tarda (PCT)
the most common type of porphyria
what causes Porphyria cutanea tarda (PCT)
mutation in uropophyrinogen decarboxylase. responsible for the 5th step in harm production
what are the symptoms of Porphyria cutanea tarda (PCT)
onychosis blistering/erosion of exposed skin hyperpigmentation hypertrichosis solar urticarial hardened patched skin (morphea) liver problems
what are the investigations for Porphyria cutanea tarda (PCT)
woods lamp
spectrophotometer
what is the treatment of Porphyria cutanea tarda (PCT)
establish and treat underlying cause
relieve skin discomfort
what causes acute intermittent porphyria
deficiency of porphobilinogen deaminase
what are the symptoms of acute intermittent porphyria
severe and poorly localised abdominal pain urinary issues (pain, retention, incontinence) psychiatric signs
what are the investigations of acute intermittent porphyria
urine and serum will show raised pophobilinogen
RBC assay
what is the treatment of acute intermittent porphyria
haemtin and haeme arginate
