Cutaneous leishmaniasis — DTM&H MCQ

Correct answer: C — Intralesional sodium stibogluconate

The correct answer is C, intralesional sodium stibogluconate. This is a solitary, painless, ulcerating nodular lesion typical of Old World cutaneous leishmaniasis (Leishmania major in Sudan), confirmed by amastigotes on slit-skin smear. For a single, uncomplicated cutaneous lesion not overlying cartilage or near the eye, intralesional pentavalent antimonial injection is the treatment of choice because it delivers high local drug concentration directly to the parasite-laden macrophages while avoiding the toxicity of systemic antimony. Dermnetnz notes that intralesional injections may be used for a single lesion or a few small lesions of cutaneous leishmaniasis, reserving systemic therapy for complicated disease. This targeted approach achieves high cure rates with minimal systemic exposure, appropriate for an otherwise well child with isolated facial disease away from critical structures. Why the other options are wrong: D. Oral fluconazole for 6 weeks: has some trial evidence specifically for L. major but is not first-line UK/WHO practice and gives inferior, inconsistent cure rates compared with antimonials. B. Cryotherapy with liquid nitrogen: may be used as adjunct or for very small lesions but is not curative alone for a 2 cm ulcerated nodule and does not address the parasite burden as reliably as intralesional antimony. A. Systemic liposomal amphotericin B: reserved for visceral leishmaniasis, mucosal disease, immunosuppressed patients, or multiple/complicated cutaneous lesions; unnecessary systemic toxicity and cost for a single accessible facial lesion. E. Oral miltefosine for 28 days: used mainly for New World cutaneous leishmaniasis with mucosal risk or when local therapy is contraindicated (e.g. lesion over cartilage); not first-line for uncomplicated Old World disease. Key point: A single, uncomplicated Old World cutaneous leishmaniasis lesion away from critical structures is treated with intralesional pentavalent antimonial (sodium stibogluconate), reserving systemic agents for multiple, mucosal, or complicated disease.

Reference: DermNet NZ, Sodium stibogluconate (clinical use in cutaneous leishmaniasis), https://dermnetnz.org/topics/sodium-stibogluconate