New World cutaneous leishmaniasis — DTM&H MCQ

Correct answer: D — Systemic antileishmanial therapy because mucosal disease risk is significant

The correct answer is D, systemic antileishmanial therapy because mucosal disease risk is significant. Belize lies within the range of Leishmania (Viannia) species, which are the New World subgenus most strongly linked to late mucosal leishmaniasis, and ear involvement (a cartilage-rich, poorly vascularised site) plus nodular lymphangitis are both recognised markers of a more aggressive, higher-risk presentation. Current UK and international travel medicine consensus (produced with UK leishmaniasis specialists) holds that local treatment can be considered for low-risk New World lesions, but systemic therapy is favoured when risk factors for mucosal spread are present, including head and neck location, multiple or large lesions, or acquisition in high-risk Andean/Amazon regions. Amastigotes on biopsy confirm active tissue infection, and species-directed systemic treatment (e.g. liposomal amphotericin B or pentavalent antimonials) reduces the risk of subsequent naso-oropharyngeal destruction, which local therapy does not reliably prevent. Why the other options are wrong: B. Topical antifungal cream for 4 weeks: Leishmania is a protozoan, not a fungus, so antifungals have no antileishmanial activity and would allow progression to mucosal disease. A. Cryotherapy without species consideration: cryotherapy is a local destructive method that ignores species and site risk, and using it indiscriminately in Viannia-endemic New World disease with head involvement risks treatment failure and mucosal dissemination. E. Oral flucloxacillin for lymphangitis: the lymphangitis here is due to nodular lymphatic spread of Leishmania, not bacterial cellulitis, so antistaphylococcal antibiotics do not address the underlying pathogen. C. Single-dose praziquantel: praziquantel is an antihelminthic used for trematodes and cestodes, and has no activity against Leishmania amastigotes. Key point: New World cutaneous leishmaniasis with head/neck (especially ear) involvement or nodular lymphangitis should prompt systemic, species-directed treatment because of the recognised risk of progression to mucosal leishmaniasis.

Reference: Blum J, Lockwood DN, Visser L, et al. Local or systemic treatment for New World cutaneous leishmaniasis? Re-evaluating the evidence for the risk of mucosal leishmaniasis. International Health 2012;4(3):153-163 (UK-authored consensus underpinning UK travel medicine practice). https://doi.org/10.1016/j.inhe.2012.06.004