Snapshot A 38-year-old recent immigrant from Brazil comes into the clinic with a 4-month history of painless, ulcerated plaques on his left arm. He denies fever, fatigue, or weight loss. Physical exam revealed ulcers of varying sizes on the left arm, covered with a yellow-white fibrinous material. There are no mucosal lesions, pallor, lymphadenopathy, or hepatosplenomegaly. A complete blood count and liver function test were within normal limits. HIV serology, AFB for lepra bacilli, and serum VDRL were all negative. Histopathological exam of a skin biopsy showed amastigotes inside histiocytes and inflammatory cells. (Cutaneous leishmaniasis) Introduction Definition a vector-borne disease transmitted by the sandfly and caused by Leishmania donovani, an intracellular protozoan parasite Diseases 2 clinical manifestations of leishmaniasis are cutaneous leishmaniasis visceral leishmaniasis ("kala-azar") Epidemiology Incidence rare in the United States and more common in Africa ETIOLOGY Pathogenesis the obligate intracellular parasite is transmitted to mammals via the sandfly the parasite binds to macrophages of the reticuloendothelial system within the macrophage (as amastigotes), the parasite undergoes binary fission and multiply until it lyses, releasing more parasite, which infect other cells, spreading the infection coinfection with HIV leishmaniasis accelerates the development of AIDS via cummulative immunosuppression stimulating the replication of the HIV virus Presentation Symptoms cutaneous leishmaniasis cutaneous lesions nontender ulceration nonpruritic diffuse cutaneous lesions can be seen in immunocompromised hosts lesions may be plaques, ulcers, and nodules diffuse lesions can appear similar to lepromatous leprosy visceral leishmaniasis darkening of the skin fever weight loss hepatosplenomegaly pancytopenia hypergammaglobulinemia leukopenia thrombocytopenia Studies Cutaneous leishmaniasis confirming the diagnosis Giemsa smear of a biopsy, dermal scraping, and/or needle aspirate allows for direct visualization of the amastigote culture polymerase chain reaction (PCR) Visceral leishmaniasis confirming the diagnosis Giemsa smear of a bone marrow aspiration (most commonly) or splenic puncture (high risk of hemorrhage) allows for direct visualization of the amastigote culture PCR Differential Lepromatous leprosy differentiating factors skin biopsy and PCR will demonstrate Mycobacterium leprae organisms results in sensory loss Treatment Conservative observation indication in immunocompetent patients with strictly cutaneous (no visceral, mucosal, or systemic involvement) disease that is spontaneously healing and known to be caused by Leishmania species Medical liposomal amphotericin B indication first-line treatment for visceral leishmaniasis Complications Complications from pancytopenia leukopenia secondary bacterial infection sepsis anemia fatigue pallor thrombocytopenia bleeding Prognosis Cutaneous leishmaniasis typically self-resolves in 3-6 months without therapy Visceral leishmaniasis a seriously progressive condition that can be lethal without treatment if untreated, death can occur within 2 years Co-infection with HIV leads to a severe and rapidly progressive fatal outcome