Comments
INITIAL SYMPTOMS:
Visceral leishmaniasis: fever, weight loss, fatigue, pancytopenia, and hepatosplenomegaly; Cutaneous leishmaniasis: an ulcer develops at the site of the sandfly bite; [CCDM]
FINDINGS (VISCERAL):
VL may present abruptly with high fever simulating malaria and other acute infections. As a chronic disease, it presents with splenomegaly and weight loss. Some patients have peripheral lymphadenopathy. [Guerrant, p. 696-706] In VL, patients have splenomegaly, pancytopenia, hypergammaglobulinemia, and in some cases, fever spikes twice a day. [Merck Manual, p. 1380] Kala-azar means black fever, and some patients have hyperpigmentation of the face and trunk. Some patients have abdominal pain, and some have diarrhea secondary to intestinal infiltration. Epistaxis related to thrombocytopenia, may occur. Elevated liver transaminases are common. Rare complications are jaundice, cirrhosis and glomerulonephritis. [ID, p. 2312] Some patients with Kala-Azar have massively enlarged spleens, which are characteristically soft and nontender. Patients with advanced disease may have epistaxis, gingival bleeding, and petechiae of the extremities. Renal disease (acute renal failure and nephrotic syndrome) are common. Many patients become cachectic and die from pneumonia and other secondary bacterial infections. [PPID, p. 3096-7] The cause of the anemia is splenic sequestration, bone marrow infiltration, hemolysis, and bleeding. [Cohen, p. 1897] "Post-kala-azar dermal leishmaniasis consists of macular, papular and/or nodular skin lesions that occur weeks to years after apparent cure of systemic disease." [CCDM, p. 341]
FINDINGS (CUTANEOUS)
The incubation period for CL ranges from 2 weeks to several months or even years. In typical patients, CL develops slowly as a shallow, painless ulcer with raised borders. Satellite lesions may appear. Regional lymphadenopathy precedes or accompanies the skin ulcers in some cases. ML is limited to about 3% of people infected with L. brazilensis or related species. Mucosal lesions develop sometime between 1 month and 20 years after the primary skin lesion. [PPID, p. 3101] CL lesions are subacute; they do not reach maximum size in less than a week. The skin lesions heal without treatment in 90% of patients within 3 to 18 months. [Cecil, p. 2015] In the New World, skin lesions caused by Leishmania brazilensis may metastasize to mucosal tissues. Mucosal lesions can spread to the nose and palate to cause tissue destruction and disfigurement. [Merck Manual, p. 1379-80] Cause of death in ML is pneumonia, laryngeal obstruction, or secondary sepsis. [Cohen, p. 1897] ML can cause difficulty swallowing and aspiration pneumonia. [Harrison ID, p. 1190] Cutaneous lesions may have marked scaling (psoriasis-like) or warty hyperkeratosis. [ID, p. 2315]
EPIDEMIOLOGY:
There are 17 species of Leishmania distributed in Europe, Asia, Africa, and South and Central America. [Cecil, p. 2025] Inapparent infections are activated by malnutrition and AIDS. Transmitted by sand flies, the reservoirs are humans, foxes, jackals, and dogs. In Bangladesh, India, and Nepal, only humans are known to be reservoirs. [CCDM, p. 342] The main forms of leishmaniasis are: 1) new world cutaneous and mucosal; 2) old world cutaneous; and 3) visceral. VL is a common opportunistic infection among AIDS patients in southern Europe. [Guerrant] Most patients with VL develop immunity and never become symptomatic. [Harrison ID, p. 1184] In the western hemisphere, forest workers are at risk for CL. [CCDM, p. 339] Most sandfly bites occur from dusk to dawn. Travelers at risk for CL include ecotourists, bird watchers, Peace Corp volunteers, missionaries, military personnel, and construction workers. [CDC Travel, p. 226]
For updated text and symptoms of infectious diseases, see iddx.com.