Dermatitis caused by physical irritants.

Background Although physical irritant contact dermatitis (PICD) is a common occupational dermatosis, it is one of the least well understood because of its multiple types, lack of diagnostic test, and the many mechanisms involved in its production. Objectives To characterize the materials and mechanisms of physical irritation of the skin. Methods We did a retrospective analysis over the past 20 years of all patients with a diagnosis of PICD at St John's Institute of Dermatology Contact Dermatitis Clinic. Results Of the 29 000 patients who attended the clinic over the study period, 392 patients were diagnosed with PICD and of these, 335 files were analysed. Conclusions Our findings show that PICD accounted for 1.15% of all patients attending the contact clinic over the study period. Diverse occupations and materials were implicated. The most common cause of PICD was low humidity due to air-conditioning, which caused dermatitis of the face and neck in office workers due to drying out of the skin.