Phototoxicity (photoirritation) is a chemically, light-induced tissue response to a photoreactive chemical, that does not involve the immune system.
Phototoxic reactions can occur in any patient who receives sufficient quantities of a drug and is exposed to enough light. Common phototoxic reactions are sunburns to the exposed areas of the skin, and hyperpigmentation to the same areas.
ICH guideline S10-Guidance on photosafety evaluation of pharmaceuticals (EMA, 2012)
Phototoxicity: Its mechanism and animal alternative test methods (Toxicological Research, 2015)
Drug-induced photosensitivity: Clinical types of phototoxicity and photoallergy and pathogenetic mechanisms (Frontiers in Allergy, 2022)
Drug-induced photosensitivity—From light and chemistry to biological reactions and clinical symptoms (Pharmaceuticals (Basel), 2021)