Contact allergy to antifungals: Results of a 12-year retrospective study

Background Contact allergy has been reported as a side effect of topical antifungals (TAFs), although most evidence has come from small case series. Objective To investigate the frequency and associated factors of contact allergy to TAFs. Methods We performed a retrospective analysis of the data of the Contact Allergy Unit of a University Dermatology Department between January 2009 and April 2021. From a cohort of 3788 patients tested in our unit, aimed testing was performed in 482 patients using TAFs from Chemotechnique Diagnostics (Vellinge, Sweden), allergEAZE, and, in some cases, commercial preparations 'as is'. Results Contact allergy to antifungals was found in 27 patients (0.71% of consecutively tested patients and 5.6% of those who had aimed testing). Foot and leg eczema were the clinical presentation in 12 (44.4%) and 10 (37.0%) patients, respectively. Positive reactions were observed mostly with econazole nitrate 1% alcohol (51.9%), miconazole 1% alcohol (48.9%), tioconazole 28% solution (40.7%), and clotrimazole 5% pet. (18.5%). Fifteen patients (55.6%) had sensitization to more than one antifungal. Conclusions Contact allergy to antifungals was uncommon and occurred mostly associated with foot dermatitis. Most patients were sensitized to more than one chemical, particularly to azoles, which may limit future choices of TAF treatment.