Leishmaniasis: A Reminder in the Face of Forgotten Travel

Abstract

Figure 2. Dermal lymphohistiocytic infiltrate with typical plasma cells (arrows). A 10-year old boy presented with a slowly growing (over 1 year) painless nodule on his left temple, pre-existing for 1 year (Figure 1). His general health was excellent; travel outside Germany was denied. The skin biopsy showed a diffuse granulomatous dermatitis mainly composed of epitheloid cells, and occasional multinucleated foreign body type giant cells. A granulomatous foreign body reaction after a ruptured epidermal cyst was diagnosed. After ineffective topical corticosteroid therapy, the first of a scheduled sequential excision was done. This specimen once more showed epitheloid granulomas now consuming the whole dermis. However, in contrast to the first biopsy, plasma cells were now spotted within the lymphohistiocytic infiltrate that prompted us to re-evaluate the diagnosis (Figure 2). Investigations for Borrelia and Mycobacteria were negative, but polymerase chain reaction revealed the presence of Leishmania donovani complex DNA. After confronting the patient and his mother with this result, the boy recalled a 2-week journey to a rural area near Barcelona, Spain, approximately 1 year before the skin lesion had occurred, thus, pointing at Leishmania infantum as the culprit infectious agent. Laboratory tests, clinical, and ultrasound investigations did not reveal any signs of systemic disease. Consequently, cutaneous leishmaniasis was diagnosed and topical 15% paromomycin/12% methylbenzethonium chloride in white petrolatum treatment under occlusion was initiated. After 2 months of treatment, the lesion completely resolved, leaving an atrophic scar.