Shedding light on a painful rash

We present a case of a rare inherited disorder--erythropoietic protoporphyria--with typical clinical manifestations. The diagnosis was suspected on the basis of a history of a light-sensitive rash and characteristic liver biopsy, and confirmed with genetic testing. The patient was followed up for more than 20 years, and ultimately developed the uncommon associated complication of liver cirrhosis. The clinical features, pathogenesis and management of erythropoietic protoporphyria are discussed herein.