Environmental dermatitis: changing patterns.

Patch tests in 1000 cases of contact allergic dermatitis observed between 1972 and 1978 are recorded in detail, and compared in general with patch tests in a previously recorded 1000 cases of contact allergic dermatitis between 1964 adn 1972. The routine use, since 1974, of patch tests as advised by the International Contact Dermatitis Research Group has increased the detection of dermatitis caused by nickel, paraphenylene-diamine and related dyes, formaldehyde and perfumes (balsam of Peru), which indicates that aimed patch tests alone may be inadequate. The number of cases of dermatitis caused by antifungal agents and topical antihistamines decreased after Commonwealth and State legislation prohibiting their use was passed.