pimpinellin/erythema

Investigations on light reactions in a patient with vitiligo are presented. The minimal erythema dose (MED) in the UVB area was approximately 1/3 of that in persons of skin type II. The application of furocoumarins (psoralens) increased light tolerance by 1 MED at 300-310 nm. Action spectrum studies

Contact with plants can cause phototoxic or rarely photoallergic reactions. Phototoxic dermatitis (photophytodermatitis) occurs after contact or ingestion of plants containing furocumarins i.e. psoralens and followed by sun exposure. Skin lesions develop usually after 24-48 hours with erythema,