BOF: 2.34
A 50-year-old male presents with a blistering rash on the
dorsum of his hands on exposure to sunlight.
He drinks 30 units of alcohol per week and smokes 15
cigarettes per day.
On examination of his hands there are blisters, erosions
scars and milia. The skin is pigmented and fragile. There are no signs of
chronic liver disease and his liver and spleen are not palpable.
Investigations show normal haematology and routine
biochemistry.
Serum ferritin 1200 micrograms per litre
Genetic testing shows homozygosity for C282Y
In this patient the most effective treatment of the skin
condition would be:
a)
Desferrrioxamine
b)
Venesection
c)
Low dose chloroquine
d)
Penicillamine
e)
Dapsone
Answer:
b)
The clinical features suggest the patient has porphyria
cutanea tarda. This is essentially a liver disorder that presents with skin
manifestations. It is caused by an endogenous inhibitor of the hepatic
uroporphyrinogen decarboxylase enzyme. The inhibitor forms in the presence of
iron and an oxidative environment. The porphyrins that are formed become toxic
when exposed to sunlight. Where iron overload is the cause of the problem the
treatment of choice is venesection both for liver damage and the porphyria.
Revision Tip
Revise porphyria cutanea tarda
KEYS to SUCCESS in Medicine page 62
