Q111: Secondary photosensitization occurs after the ingestion of: - Veterinary Public Health, Pharmacology & Toxicology - ICAR AIEEA PG 2024 - Veterinary Science | Agrigyan

Secondary (hepatogenous / type III) photosensitization is caused by hepatic damage or bile duct occlusion that impairs the excretion of phylloerythrin (a photodynamic porphyrin breakdown product of chlorophyll produced by ruminal microbes). Ingestion of Lantana camara contains hepatotoxic triterpenes (Lantadene A and B) that induce severe cholestasis and hepatopathy, leading to toxic phylloerythrin retention in skin capillaries. Hypericum and Fagopyrum cause primary (type I) photosensitization.