Porphyria
Last updated: Saturday, 07, August, 2010
| 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 - 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. |