Clinical Presentation

The most common clinical presentation is single or multiple localized ulcers or nodules. Typically, ulcerative CL starts as a small, erythematous papule at the site where promastigotes, the infective form of the parasite, are inoculated by the bite of a sandfly. The incubation period is usually several weeks or months, but lesions can appear within a few days or several years after leaving an endemic area. In most cases, within a few weeks the papule enlarges, crusts over, and breaks down into a slow-growing ulcer up to several centimeters in diameter. The ulcer is shallow and well-defined, with a raised erythematous border and central granulation tissue. As the ulcer grows, patients develop a delayed hypersensitivity reaction to leishmanial antigens. Surrounding inflammation may be minimal or quite marked. The ulcer heals slowly, leaving a depressed, atrophic scar. Subcutaneous nodules with a sporotrichoid pattern and satellite lesions are common, mainly in the West. Lesions may be hyperkeratotic and do not always ulcerate. There may be involvement of proximal lymph nodes. Macules, papules, plaques, nodules, and psoriasiform, varicelliform, eczematous, and keloidal lesions are uncommon.