Porphyria

Porphyria

Porphyria	Consult pathologist regarding appropriate specimens. If patient has intermittent symptoms, specimens for porphyrin analysis should be collected during a symptomatic period. Skin biopsy of lesions may suggest porphyria and can exclude other causes of bullous and scarring lesions. Specific porphyrin disorders may have the following manifestations: (a) acute neurological porphyrias - abdominal pain, constipation, hypertension, neuropathy, psychiatric symptoms; (s) photosensitive skin fragility with scarring; (u) solar urticaria - pruritus, erythema and swelling with ultimate scarring. Coproporphyrinuria may occur in cholestasis, and poisoning with heavy metals (eg lead, mercury) or certain chemicals (eg hexachlorbenzene).
Porphyria cutanea tarda (s)	Porphyrins - urine . Porphyrins - faeces only occasionally required. Uroporphyrinogen decarboxylase - red cells , if hereditary form suspected.
Protoporphyria (u)	Porphyrins - red cell .
Acute intermittent porphyria (a)	Porphobilinogen - urine , porphyrins - urine . Porphobilinogen deaminase - red cell , for confirmation of diagnosis and in asymptomatic family members.
Porphyria variegata (s,a)	Porphyrins - urine , porphobilinogen - urine ; porphyrins - faeces .
Hereditary coproporphyria (s,a)	Porphyrins - urine , porphobilinogen - urine ; porphyrins - faeces .
Congenital erythropoietic porphyria (s)	Porphyrins - urine and porphyrins - red cell .
Plumboporphyria (a)	5-aminolaevulinate - urine . Porphobilinogen synthetase - red cell . Lead - blood , to exclude lead toxicity as the cause.