PURPURIC PHOTOTHERAPY-INDUCED ERUPTION IN TRANSFUSED NEONATES - RELATION TO TRANSIENT PORPHYRINEMIA

Objective. Blue light phototherapy is commonly administered to neonate s as treatment of indirect hyperbilirubinemia, often in conjunction wi th blood transfusions to treat hemolytic anemia. We observed a distinc tive cutaneous complication of phototherapy in six neonates with hyper bilirubinemia. Methodology. We studied the clinical and histologic cha racteristics of the eruption, as well as the porphyrin levels in affec ted neonates. Five of the patients had erythroblastosis fetalis; the o ther had profound anemia from twin-twin transfusion. All of the neonat es developed purpuric patches at sites of maximal exposure to the phot otherapy lights, with dramatic sparing at shielded sites within 24 hou rs after initiation of the phototherapy. On discontinuation of phototh erapy, all eruptions cleared within 1 week. Examination of skin biopsy sections showed purpura without significant inflammation or keratinoc yte necrosis. Plasma porphyrins (copro- and proto-) were elevated in t he two patients in which they were assessed. Conclusions. The distribu tion of the eruption in areas exposed to light and presence of circula ting porphyrins suggest that porphyrinemia may underlie the light-indu ced purpuric eruption. Additional studies will be required to determin e definitively the mechanisms of both the purpuric phototherapy-induce d eruption and the development of increased blood porphyrin levels in these transfused neonates.