Both cutaneous and mucocutaneous forms generally yield normal laboratory values, although complete blood counts may show mild anemia, leukopenia, or thrombocytopenia.3 US travelers may consult numerous physicians before leishmaniasis is diagnosed. The median time from recognition of skin lesions to drug treatment is 112 days.4
Lab results
The patient’s complete blood count with differential, electrolytes, creatinine, liver function tests, and electrocardiogram were within normal limits. An infectious disease consultant suggested direct microscopic visualization of skin biopsies, dermal scrapings, and needle aspirates using Giemsa and Leishman stains, but these failed to reveal any parasitic organisms. It was thought these results were most likely false negatives.
In the best situation, the diagnosis of leishmaniasis is confirmed by isolating, visualizing, and culturing the parasite from infected tissue. Dermal scrapings or needle aspirates may reveal Leishmania amastigotes using a Giemsa stain. Early in the course of localized disease, Leishmania organisms may be numerous and found readily within the cytoplasm of macrophages. However, biopsy specimens from old lesions (>6 months), partially or incompletely treated, are frequently negative.
In vitro culture of the parasite from tissue samples using Nicolle-Noy-McNeal medium is often obtained to aid in diagnosis and to identify Leishmania species. With successful culture, the parasite can be sent to the Centers for Disease Control for speciation. New, rapid tests for leishmaniasis are being developed.
Treatment
Although 90% of skin lesions caused by cutaneous leishmaniasis heal spontaneously to form atrophic scars, the infectious disease consultant recommended treatment to prevent development of disfiguring mucocutaneous disease (level of evidence [LOE]=5)—otherwise, immunity may not be complete and skin ulcers can recur.
Experts believe it is important to treat cutaneous leishmaniasis if a species known or suspected of being capable of converting to the mucocutaneous disease form—eg, New World L braziliensis—is present. These lesions may appear months or even years after the initial exposure, and can be refractory to further treatment. However, surgical excision usually is not recommended because of the risk of relapse and further cosmetic disfigurement.3
Yearly follow-up to evaluate for recurrence or evolution of mucocutaneous leishmaniasis is crucial; early treatment of this form of the disease is more efficacious and can yield more favorable outcomes by limiting potential facial involvement (LOE=5).