Delayed Hypersensitivity to Intralesional Meglumine Antimoniate for Cutaneous Leishmaniasis.

Intralesional injection of pentavalent antimonials is a recommended treatment of cutaneous leishmaniasis (CL). We describe an allergic response to meglumine antimoniate after intralesional treatment of a CL lesion. A 61-year-old male resident of the United Kingdom developed an enlarging, nontender nodule on the right earlobe. Histological analysis and polymerase chain reaction testing confirmed a diagnosis of CL. Intralesional therapy with meglumine antimoniate was initiated, and two infiltrations were completed. After each administration, localized swelling and erythema were noted, and after the second infiltration, an urticarial rash also appeared on the patient's hands. An immunological hypersensitivity reaction, with mixed Type I and Type IV features, was suspected, and treatment was discontinued. The patient declined further treatment, and the lesion gradually resolved, with full recovery 36 months after the first treatment. Recent travel history suggested Spain as the most likely country of acquisition. This report also reviews the literature on allergy to antimonial drugs. The prevalence of pentavalent antimonial hypersensitivity varies considerably between studies, likely due to differences in reporting of adverse events. Clinicians treating leishmaniasis should be aware of this adverse effect of antimonials, which may require use of alternative therapies.