Making sense of the porphyrias.

Patients with cutaneous porphyrias can be worrying for dermatologists. The diseases are rare enough to be unfamiliar, are associated with internal diseases, can have genetic implications, and are associated with incomprehensible biochemical pathways. In this review, I will try to explain why porphyrias occur, why they present as they do in the clinic, and provide a checklist for treating patients with porphyria.