Irritant contact dermatitis.

Irritant contact dermatitis (ICD) is the most common form of contact dermatitis. It represents the cutaneous response to the toxic/physical effects of a wide variety of environmental agents. Nowadays, it is recognized that irritancy does not represent a single monomorphous entity but rather a complex biologic syndrome with diverse pathophysiology and clinical manifestations. The clinical presentation is highly variable depending on several factors, including properties and strength of the irritant, dose, duration and frequency of exposure, environmental factors, and skin susceptibility. The pathophysiological mechanism depends on activation of the innate immune system and involves skin barrier disruption, cellular changes, and release of proinflammatory mediators that directly recruit and activate T lymphocytes. The diagnosis of irritant contact dermatitis is often clinical, and involves a comprehensive history and examination, as well as the exclusion of allergic contact dermatitis with patch testing. Recent advances in understanding the pathogenesis as well as better awareness of the clinical significance of ICD will lead to a improved care for our patients.