Medicament contact allergy

During a two-year period contact allergy to topically applied medicaments in the urban population of Malmö was investigated prospectively by patch testing patients with suspected products and their ingredients as well as with standard allergens. Contact dermatitis to specified medicaments was diagnosed in 40 of 408 patients with a positive patch test, and to standard allergens of medicament nature in a further 123 patients. Medicament contact allergy therefore constituted 40% of all allergies observed. This is equivalent to an annual incidence of 43/100,000. Among responsible products the leading antigens were ethylenediamine, phenylbutazone, myristyl alcohol, chlorocresol and cincocaine. In comparison with patients having other contact allergies the present material of medicament contact allergy was characterized by a rather high mean age (57 years), a higher percentage of males, a higher percentage of lower leg and anogenital dermatitis, and a lower percentage of hand dermatitis. A secondary spread occurred in half the cases of lower leg and anogenital dermatitis.