Sun avoidance, avoidance of tanning booths, and usage of broad spectrum sunscreen that blocks both UVA and UVB. Identification and avoidance of the offending drug.
Pseudoporphyria
Harderoporphyria
Erythropoietic protoporphyria
Porphyria
Scurvy
Megavitamin-B6 syndrome
Hemosiderinuria
Hepatic porphyria