Porphyria

Key Information

Appropriate Tests

 

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, if hereditary form suspected.

Protoporphyria (u)

Porphyrins red cell.

Acute intermittent porphyria (a)

Porphobilinogen urine, Porphyrins urine. Porphobilinogen deaminase, 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)

Urine ALA (5-aminolaevulinate).

Uroporphyrinogen synthetase. Lead, to exclude lead toxicity as the cause.