A 6-year-old male has painful edema and erythema of his posterior forearms, dorsal hands, and face several hours following sun exposure. He says a tingling and intense, painful burning sensation precede the rash when it occurs, starting immediately after sun exposure. These episodes recover in a few days. Episodes appear seasonal, with increased symptoms in the spring and summer months. Blood levels of protoporphyrin IX and metal-free protoporphyrin elevated, but no porphyrins are detected in the urine. Which of the following is the most likely enzyme deficient in this patient?
A. Porphobilinogen deaminase
B. Uroporphyrinogen decarboxylase
C. Coproporphyrinogen oxidase
D. Ferrochelatase
E. Protoporphyrinogen oxidase