New World cutaneous leishmaniasis in Adult
Cutaneous leishmaniasis results from infection of the skin with obligate intracellular parasites of the Leishmania genus. The parasites are transmitted by the bite of infected female phlebotomine sandflies (species in the Lutzomyia genus in the New World and in the Phlebotomus genus in the Old World). The World Health Organization (WHO) estimates that 1.5 million new cases of cutaneous leishmaniasis occur each year, and leishmaniasis is on the WHO's list of neglected tropical diseases. Children are more frequently affected due to increased exposure to sandflies and underdeveloped immune systems. Over 90% of the cases occur in the following countries:
Afghanistan, Algeria, Iran, Iraq, Pakistan, Saudi Arabia, and Syria.
Brazil and Peru.
In economically developed countries, infection is commonly associated with travel and immigration patterns. In addition, climate change may be altering patterns of acquisition. In Texas, for example, endemic leishmaniasis may be more common than travel-acquired disease due to more favorable environmental conditions for leishmaniasis vectors and reservoirs.
NWCL typically is a zoonotic disease with various mammalian reservoir hosts, including dogs, rodents, opossums, bats, armadillos, and others. Humans are incidental hosts of infection. The most common leishmanial species that cause NWCL include those in the Leishmania subgenus (eg, Leishmania mexicana, Leishmania amazonensis, etc) and the Viannia subgenus (eg, Leishmania braziliensis, Leishmania panamensis, Leishmania guyanensis, etc). All species associated with NWCL can cause localized cutaneous disease. Mucocutaneous leishmaniasis is most commonly caused by L braziliensis and L panamensis and can be life-threatening. Leishmania infantum can also cause visceral disease.
The appearance and evolution over time of the skin lesions of NWCL can vary widely. Typically, the primary lesion starts as erythema at the site of a sandfly bite. Thereafter, it evolves, over weeks to months, from a papule to a nodule, which may then ulcerate. Some lesions persist as nodules or plaques. Lymphangitis that ascends the lymphatic chain (sporotrichoid spread) and lymphadenopathy (sometimes bubonic) can be seen; the latter may precede the presence of skin lesions. Pruritus, pain, and bacterial superinfection may also be present. Systemic symptoms are rarely seen. Ultimately, over months to years, lesions may heal without therapy, leaving hypopigmented, atrophic scars.
Reactivation of infection, typically first noted at the margins of scars, can occur months, or sometimes years, after clinical resolutions of lesions.
Mucosal leishmaniasis occurs simultaneously with localized cutaneous leishmaniasis or, more commonly, years after infection. Unlike localized cutaneous leishmaniasis, mucosal disease does not heal on its own and can be fatal.
Diffuse cutaneous leishmaniasis (DCL) is a rare variant caused by L mexicana and L amazonensis. It occurs in the context of leishmanial-specific anergy and is manifested by disseminated, nonulcerated nodules.
B55.1 – Cutaneous leishmaniasis
402141004 – American cutaneous/mucocutaneous Leishmaniasis
- Furuncle / carbuncle
- Cutaneous tuberculosis
- Buruli ulcer
- Mycobacterium marinum infection
- Infection with other atypical mycobacteria
- Basal cell carcinoma
- Squamous cell carcinoma
- Foreign body reaction
- Traumatic ulceration
- Arthropod bite