Neomycin--a frequent contact allergen.

The incidence of allergic contact dermatitis from neomycin evaluated in relation to 1381 verified cases of allergic contact dermatitis showed a progressive increase (5.00, 7.69, 10.18%) over a three-year period (1990-1992). Sensitivity to neomycin was investigated with special reference to possible cross-reactions between neomycin and the allergens that are commonly used in the manufacture of cosmetic products. Contact sensitivity to neomycin was found to be present with the other diagnoses, such as atopic dermatitis, seborrhoeic dermatitis, hypostasic dermatitis and psoriasis vulgaris.