Phytophoto-dermatitis affecting the skin on the back of a woman's neck. Phytophoto-dermatitis is used to describe the skin inflammation in the region of actual contact with allergenic plant substances which is potentiated by the action of sunlight. Dermatitis is a rather general term used to describe the inflammatory reactions of the skin to external agents, as described in insindustrialins or in inscontactins dermatitis. The term eczema has a similar meaning but is applied to cases of systemic or constitutional dermatitis which result from endogenous causes.