Challenges in Diagnosing Biopsy-Negative Cutaneous Leishmaniasis and Role of Systemic Therapies

Cutaneous leishmaniasis (CL) typically manifests as one or more chronic, non-healing skin ulcers, often with raised borders and central necrosis, accompanied by erythema. These lesions are most commonly seen on exposed areas. However, the clinical presentation of CL can vary based on factors such as the <i>Leishmania</i> species, the host's immune response, and the region of infection. Biopsy typically confirms the diagnosis of CL by identifying amastigotes, the intracellular form of the parasite, in tissue samples. However, there are rare instances where a biopsy fails to detect the amastigotes, resulting in a negative biopsy despite a clinical presentation highly suggestive of CL. This scenario complicates the diagnostic process and may lead to delays in proper treatment. We present the case of a middle-aged gentleman from a desert region of the country who had several weeks of hand lesions unresponsive to antibiotic therapy. Although a biopsy of the lesions was negative, he was clinically diagnosed with CL based on positive <i>Leishmania</i> serology and the gross appearance of the lesions. There was no evidence of systemic involvement on bone marrow biopsy, and the lesions significantly improved with treatment using amphotericin B and miltefosine.