AN OTHERWISE healthy 13-month-old boy was taken to the pediatrician for evaluation of "crying when in the sun," leathery appearance of the skin on the dorsum of the hands (Figure 1), and irritation and redness of the skin of the upper lip and bridge of nose. Five months later, when the child moved from a northern climate to Georgia, the mother noted marked worsening of the redness and sun-induced sensitivity of his skin. A clinical diagnosis of erythropoietic protoporphyria (EEP) was made. Laboratory studies showed a florescence (4+) of the red blood cells. Erythrocyte protoporphyrin level was 3.96 µmol/L (normal, <0.62 µmol/L). A biopsy specimen from an affected area of skin on the right dorsal hand is shown in Figure 2.