Dissemination in cutaneous leishmaniasis. II. Satellite papules and subcutaneous induration.

In a field study of cutaneous leishmaniasis (CL) due to Leishmania major, zymodeme Lon-4, in an endemic focus in Saudi Arabia, 80 patients in a group of 643 patients (12.44%) were found to have multiple, inflammatory, satellite papules (SP) around one or more CL lesions. The SP often appeared to erupt after commencement of antileishmanial treatment. They showed a range of morphology and pathology, and comparisons with corresponding CL lesions showed important differences. Amastigotes were seen in only one of seven biopsy specimens. Another morphologic feature, subcutaneous induration (SCI), was noted on routine palpation in 20 patients in the same patient group (3.11%). The SCI either was radiating all around the lesion and appeared as an "iceberg nodule" or was present as a "tonguelike" process proximal to the CL lesion. Amastigotes were seen in four of nine biopsy specimens of SCI. SP and SCI represent reactions to local dissemination of the parasite or its antigenic products, and as morphologic features aid in the clinical diagnosis of CL.