Irritant contact dermatitis (ICD) is a complex biologic syndrome with multiple clinical manifestations and a diverse pathophysiology, involving a combination of both exogenous and endogenous factors. The clinical spectrum of the ICD syndrome is broad and ranges from slight scaling and faint erythema to caustic burns, or to an eczematous condition clinically indistinguishable from ACD. The wide diversity in the morphology and temporal evolution of the clinical lesions allows for the definition of various clinical phenotypes of ICD.