Erythropoietic Protoporphyria: Initial Diagnosis With Cholestatic Liver Disease.

The porphyrias are a group of rare metabolic disorders that result from defects in heme biosynthesis. Erythropoietic protoporphyria (EPP) is the most common inherited porphyria in children and is diagnosed in most individuals after the onset of cutaneous manifestations. Hepatobiliary disease affects the minority of individuals with EPP and usually manifests in patients with an established diagnosis of EPP. We report on a classic but rare case of EPP that masqueraded as cholestasis. An 8-year-old boy was referred to the Hepatology Clinic after an abrupt onset of jaundice with a longstanding history of dermatitis. The diagnosis of EPP was established with liver biopsy, which revealed dense, dark-brown pigment in hepatocytes and Kupffer cells that, on polarization, displayed bright-red birefringence and centrally located Maltese crosses. Plasma total porphyrins and erythrocyte protoporphyrin were elevated and confirmed a diagnosis of EPP. We hope to raise awareness of this diagnosis among pediatricians, hepatologists, and pathologists and increase the consideration of EPP in patients with cholestatic liver disease and chronic dermatitis. [ABSTRACT FROM AUTHOR]