Allergic contact dermatitis caused by amorolfine in a nail lacquer

Topical drugs containing amorolfine are frequently used for the treatment of mycosis. Many people use amorolfine to empirically treat suspected fungal nail infection with once or twice weekly application. Amorolfine is usually well tolerated; only minor localised adverse events have been reported. A 45‐year‐old, non‐atopic woman presented with itchy vesicles and blisters containing partly purulent fluid on her right first toe (Figure 1). She reported that she had been applying, for a couple of weeks, a nail lacquer containing amorolfine 5.0% that she had acquired to treat a suspected fungal nail infection. Cessation of this treatment and application of topical clobetasol dipropionate (twice daily) and oral amoxicillin/clavulanic acid (875/125 mg, twice daily for 7 days) led to resolution within 2 weeks. Six weeks later patch tests with the SIDAPA (Società Italiana di Dermatologia Allergologica Professionale e Ambientale) baseline series (Euromedical, Calolziocorte, Italy) and the nail lacquer “as is” were performed. Patch tests were applied on the back and left in occlusion for 2 days with Al Test (Euromedical) on Scanpor Tape (Norgesplaster, Vennesla, Norway). Readings performed at day (D)2, D4 and D71 showed a positive reaction to the nail lacquer. Subsequently, patch tests with all nail lacquer ingredients were performed with positive reaction to amorolfine 1.0% pet. Ten healthy subjects were patch tested with amorolfine 1.0% pet., with negative results.