Pustular allergic contact dermatitis to isoconazole nitrate.

The topical imidazole antimycotics are widely used and are an infrequent cause of contact allergy. We report on a woman, who developed an unusual clinical picture of allergic contact dermatitis, namely papulo-pustular reaction, evoked by an isoconazole nitrate-containing cream. The histopathologic changes included subcorneal pustules, spongiosis, and an inflammatory infiltrate composed mainly of lymphocytes and some eosinophils and neutrophils. The patient demonstrated a severe vesicular reaction to isoconzole nitrate as is and at an imidazoles concentration of 0.5%. No cross-reactivity with other imidazole antimycotics was noted.