Acute abdominal pain and neurologic features of variegate porphyria and acute intermittent porphyria are similar - but urine becomes brown on standing in AIP and faecal protoporphyria is raised in VP.
Cutaneous lesions of VP, porphyria cutanea tarda, bullous and other photosensitivity disorders are similar. VP is distinguished by elevated faecal protoporphyrin and coproporphyrin.
Plasma fluorescence scanning helps differentiate variegate porphyria from acute intermittent porphyria, erythropoietic protoporphyria, congenital erythropoietic porphyria, porphyria cutanea tarda, and hereditary coproporphyria (1).
- (1) Hift RJ et al. Plasma fluorescence scanning and fecal porphyrin analysis for the diagnosis of variegate porphyria: precise determination of sensitivity and specificity with detection of protoporphyrinogen oxidase mutations as a reference standard. Clin Chem. 2004;50(5):915-23
Last reviewed 01/2018