Cutaneous porphyria in a neonate with tyrosinaemia type 1

A term infant born to consanguineous parents presented at birth with hypogl ycaemia, thrombocytopenia, coagulopathy and hyperbilirubinaemia associated with polycythaemia due to delayed cord clamping. Despite phototherapy and c orrection of polycythaemia by partial exchange transfusion, coagulopathy, h ypoglycaemia and conjugated hyperbilirubinaemia persisted, suggesting hepat ic failure. Metabolic work-up led to the diagnosis of tyrosinaemia type 1 o n day 4. Two - (2-nitro-4-trifluoromethylbenzoyl) - 1,3 cyclohexanedione (N TBC) treatment, started on day 5, resulted in progressive clinical improvem ent and unambiguous biochemical response. Severe skin purpuric lesions occu rred in areas exposed to phototherapy. These resolved slowly after its disc ontinuation. Urine analysis sampled just before and 6 days after starting N TBC treatment showed high levels of type I coproporphyrin isomers. Such fin dings do not seem directly related to tyrosinaemia type 1 where succinylace tone inhibits delta-aminolevulinic acid (delta-ALA) dehydratase and where t he accumulation of delta-ALA results in neurotoxicity without photosensitiv ity. Conclusion We describe a cutaneous form of porphyria in a neonate presentin g with severe liver failure due to tyrosinaemia type I. This porphyria is t entatively attributed to a secondary accumulation of coproporphyrins due to cholestasis, as reported in the bronze baby syndrome and recently describe d in neonates with purpuric phototherapy-induced eruption, rather than to a primary defect of porphyrin metabolism. The hypothesis of a direct effect of tyrosinaemia type 1 on porphyrin excretion is also discussed.