Leishmaniasis

Synonyms

Old World cutaneous leishmaniasis: oriental sore, Aleppo/Baghdad boil, Delhi boil.

New World cutaneous leishmaniasis: chiclero ulcer; uta; jungle yaws.
Mucocutaneous leishmaniasis: espundia.

Epidemiology

Approximately 1 million new cases of cutaneous leishmaniasis worldwide per year. Geographical distribution: cutaneous leishmaniasis (CL): Middle East and South America; mucocutaneous leishmaniasis (MCL): Central and South America.

Definition

Infection with Leishmania; a protozoan. Three typical clinical forms (see Classification).

Aetiology & Pathogenesis

Transmission by the female phlebotomus sandflies only. Depending on species and different animal reservoirs (for example wild rabbits and dogs for L. infantum), different clinical patterns occur (see Classification).

CL species:

the Old World: L. major, L. tropica, L. aethiopica, L. infantum
the New World: L. mexicana and L. brasiliensis
MCL species: L. braziliensis

Signs & Symptoms

CL: an erythematous papule at the site of the sting progresses within weeks to months to an ulcerated hyperkeratotic plaque. Occasional satellite papules are present. Usually the lesion heals spontaneously over a period of months with scarring. MCL: mutilating mucosal lesions (the nose or mouth mainly in New World infections).

Localisation

Usually on exposed sites (face, forearms, legs).

Classification

Different forms of cutaneous leishmaniasis include:

Self-healing localized cutaneous leishmaniasis.
leishmaniasis recidivans.
mucocutaneous leishmaniasis.
anergic diffuse cutaneous leishmaniasis.
disseminated leishmaniasis.
Post Kala-azar Dermal Leishmaniasis (PKDL): cutaneous manifestation observed in some visceral leishmaniasis patients after successful treatment (see 11.3.2).

Laboratory & other workups

Giemsa-stained smears (tissue impression smears, dermal scrapping or needle aspiration) or biopsy specimens: the presence of amastigote parasites; culture (Novy-MacNeal-Nicolle (NNN)medium); serology (ELISA and immunofluorescence studies), PCR assay.

Dermatopathology

Early lesions: amastigote parasites in dermal macrophages. The chronic form: granulomatous inflammation (tuberculoid-like granulomas).

Course

CL may resolve spontaneously; MCL: progressive course; potentially lethal due to secondary infections and aspiration pneumonia; visceral leishmaniasis: serious and progressive disease; if untreated, lethal in 75-95% of patients.

Complications

Diffuse cutaneous leishmaniasis, persistence of the infection, relapses, involvement of mucous membranes (L. braziliensis ) and systemic spread (L. donovani, L. infantum), particularly in immunosuppressed patients.

Diagnosis

Travel history and clinical features. Identification of a parasite in a smear preparation or skin biopsy, PCR assay or with culture.

Differential diagnosis

Tropical ulcers: infiltrates due to other causes; ecthyma in travellers.

Prevention & Therapy

Prevention: vector control, use of insect repellents, protective clothing, fine-mesh screens.

Therapy includes cryosurgery, local heat therapy, excision, topical paromomycin, intralesional or systemic antimony compounds, oral miltefosine and oral itraconazole. Cutaneous leishmaniasis of Old World subtypes is often self-limited.

Special

None.

2.4.1 Leishmaniasis