Evaluation of contact sensitivity to topical drugs in patients with contact dermatitis

Background and Design: Topical drugs are an important group of contact allergens. The present study aimed to evaluate contact sensitivity to topical drugs in patients with contact dermatitis. Materials and Methods: Between 2003 and 2008, 129 patients were followed up at the Department of Dermatology at Ankara University School of Medicine with clinically suspected contact sensitivity to topical drugs. In this study, the patch test reactions to the European Standard Battery and topical drugs used by the patients and medicament patch test results were evaluated. Results: Positive patch test reaction to one or more allergens was found in 80 (62.0%) of 129 patients included in the study. Sixty-one of the 80 patients (61/129, 47.3%) had positive patch test reaction to medicaments. Medicament sensitivity was detected in 37.9% (49/129) of subjects. Nitrofurazone was found to be the most common allergen (18.6%). Discussion: The present study showed that topical drugs are a frequent cause of allergic contact dermatitis. Therefore, the probability of contact sensitivity to topical drugs should also be considered in patients with the clinical diagnosis of allergic contact dermatitis and, suspected cases should be evaluated further with patch testing in order to find the responsible allergens.