Current concepts of irritant contact dermatitis.

Correspondence to: Dr J S C English, Consultant Dermatologist, Queen’s Medical Centre, University Hospital, Nottingham NG7 2UH, UK; john.english@ mail.qmcuh-tr.trent.nhs.uk _________________________ C ontact dermatitis is an eczematous eruption caused by external agents, which can be broadly divided into irritant substances that have a direct toxic effect on the skin (irritant contact dermatitis, ICD) and allergic chemicals where immune delayed hypersensitivity reactions occur (allergic contact dermatitis, ACD). Contact urticaria is an immediate reaction from exposure to a substance and is mediated by either irritant or immunological mechanisms; it can resemble ICD but the onset is immediate and short lived. Many allergenic chemicals are also irritants and it is thought that ICD enhances the development of ACD. ICD is the commonest presentation of occupational skin disease. In industries where workers engage in wet work, almost all workers develop some degree of irritant contact dermatitis. Most workers with mild occupational irritant contact dermatitis do not seek medical attention and accept the condition as an occupational hazard. A better understanding of irritant contact dermatitis will lead to improved management of this common condition.