Given the concern for mucocutaneous leishmaniasis with this particular species, otolaryngology was consulted; however, the patient did not demonstrate mucocutaneous disease. Because of the elevated risk for persistent disease with L panamensis, systemic therapy was indicated and administered: IV amphotericin B 200 mg on days 1 through 5 and again on day 10. Improvement in the ulcer was seen after the 10-day regimen was completed.
Comment
Leishmaniasis can be broadly classified by geographic region or clinical presentation. Under the geographic region system, leishmaniasis can be categorized as Old World or New World. Old World leishmaniasis primarily is transmitted by Phlebotomus sandflies and carries the parasites Leishmania major and Leishmania tropica, among others. New World leishmaniasis is caused by Lutzomyia sandflies, which carry Leishmania mexicana, Leishmania braziliensis, Leishmania amazonensis, and others.6
Our patient presented with cutaneous leishmaniasis, one of 4 primary clinical disease forms of leishmaniasis; the other 3 forms under this classification system are diffuse cutaneous, mucocutaneous, and visceral leishmaniasis, also known as kala-azar.3,6 Cutaneous leishmaniasis is limited to the skin, particularly the face and extremities. This form is more common with Old World vectors, with most cases occurring in Peru, Brazil, and the Middle East. In Old World cutaneous leishmaniasis, the disease begins with a solitary nodule at the site of the bite that ulcerates and can continue to spread in a sporotrichoid pattern. This cutaneous form tends to heal slowly over months to years with residual scarring. New World cutaneous leishmaniasis can present with a variety of clinical manifestations, including ulcerative, sarcoidlike, miliary, and nodular lesions.6,7
The diffuse form of cutaneous leishmaniasis begins in a similar manner to the Old World cutaneous form: a single nodule spreads widely over the body, especially the nose, and covers the patient’s skin with keloidal or verrucous lesions that do not ulcerate. These nodules contain large groupings of Leishmania-filled foamy macrophages. Often, patients with diffuse cutaneous leishmaniasis are immunosuppressed and are unable to develop an immune response to leishmanin and other skin antigens.6,7
Mucocutaneous leishmaniasis predominantly is caused by the New World species L braziliensis but also has been attributed to L amazonensis, L panamensis, and L guyanensis. This form manifests as mucosal lesions that can develop simultaneously with cutaneous lesions but more commonly appear months to years after resolution of the skin infection. Patients often present with ulceration of the lip, nose, and oropharynx, and destruction of the nasopharynx can result in severe consequences such as obstruction of the airway and perforation of the nasal septum (also known as espundia).6,7
The most severe presentation of leishmaniasis is the visceral form (kala-azar), which presents with parasitic infection of the liver, spleen, and bone marrow. Most commonly caused by Leishmania donovani, Leishmania infantum, and Leishmania chagasi, this form has a long incubation period spanning months to years before presenting with diarrhea, hepatomegaly, splenomegaly, darkening of the skin (in Hindi, kala-azar means “black fever”), pancytopenia, lymphadenopathy, nephritis, and intestinal hemorrhage, among other severe manifestations. Visceral leishmaniasis has a poor prognosis: patients succumb to disease within 2 years if not treated.6,7
Diagnosis—Diagnosing leishmaniasis starts with a complete personal and medical history, paying close attention to travel and exposures. Diagnosis is most successfully performed by polymerase chain reaction analysis, which is both highly sensitive and specific but also can be determined by culture using Novy-McNeal-Nicolle medium or by light microscopy. Histologic findings include the marquee sign, which describes an array of amastigotes (promastigotes that have developed into the intracellular tissue-stage form) with kinetoplasts surrounding the periphery of parasitized histiocytes. Giemsa staining can be helpful in identifying organisms.2,6,7