Photosensitivity genodermatoses, porphyrias

Sunlight has many biological effects. If the average or low dose of light produces more pronounced, intense, or unusual acute or chronic skin symptoms, it is called photosensitivity. Rarely, photosensitivity is due to a genetic abnormality. Genophotodermatoses result in photosensitivity due to mutations in proteins with a protective function against light, while porphyrias result in the accumulation of phototoxic metabolites. Most of them also have a genetic background. The present report describes these diseases in the light of the latest literature data but does not cover diseases associated with melanin synthesis, which also results in photosensitivity.