Unblinded by the Lights

A 24-year-old man was transferred to the hospital for evaluation of jaundice and abdominal pain. He had a lifelong history of severe photosensitivity and wore long-sleeved shirts and sunscreen to limit sunburn. A 24-year-old man was transferred to the hospital for evaluation of jaundice and abdominal pain. He had a lifelong history of severe photosensitivity and wore long-sleeved shirts and sunscreen to limit sunburn. During the evaluation for abdominal pain, an initial upper endoscopy was negative. However, postendoscopy melena prompted a second look, which revealed multiple mucosal burns caused by the light source of the endoscope during the initial procedure (Panel A). Burns also developed on his fingers from the light source of a pulse oximeter (Panel B). A workup revealed elevated red-cell free protoporphyrin levels and elevated levels of porphyrin in . . .