RESUMEN
BACKGROUND: Porphyria cutanea tarda (PCT) is rare in childhood and association with bone marrow transplant has occasionally been reported. PATIENTS AND METHODS: A 13-year-old boy was referred to our department for bullous lesions on sun-exposed areas. His past medical history revealed acute biphenotypic leukaemia with complete remission after allogeneic hematopoietic stem cell transplantation (unrelated donor). Complications of bone marrow transplant comprised anaemia (treated by blood transfusions), primary cytomegalovirus (CMV) infection, pulmonary aspergillosis and acute digestive graft-versus-host disease. The diagnosis of type I sporadic PCT was based on high levels of porphyria and normal erythrocytic uroporphyrinogen decarboxylase activity. The bullous lesions disappeared on bleeding, but the patient subsequently developed sclerodermiform lesions. DISCUSSION: An association between PCT and bone marrow transplant has been reported previously in two independent cases, of which one involved a child. The causative role of bone marrow transplantation in the development of PCT could be related to several triggering factors: primary CMV infection, hepatotoxic drugs, blood transfusion and possible chronic hepatic graft-versus-host disease. CONCLUSION: We report the second case in a child of type I PCT associated with bone marrow transplantation. This new case reinforces the hypothesis of a non-random relationship between the two conditions.