Symptoms, transmission, and current treatments for cutaneous leishmaniasis
What is cutaneous leishmaniasis?
Cutaneous leishmaniasis is the most common form of leishmaniasis. It is caused by over 15 different species of the protozoan parasite Leishmania, transmitted by infected female sandflies.
Although cutaneous leishmaniasis is not life-threatening, it can have devastating effects on local communities. It causes disfiguring skin lesions that can leave life-long scars and lead to severe social stigma, especially for women and children. Consequences include ostracism, less education, and economic loss. These effects are especially severe since cutaneous leishmaniasis mostly affects people who already have only limited resources.
Mucocutaneous leishmaniasis can present as a complication of cutaneous leishmaniasis and can occur several months or even years after skin ulcers heal. Lesions can lead to partial or total destruction of the mucosal membranes of the nose, mouth, and throat cavities and surrounding tissues, resulting in social stigma and disability. Unlike most forms of cutaneous leishmaniasis, mucocutaneous leishmaniasis is unlikely to heal on its own; in cases of severe mucocutaneous leishmaniasis, people who do not receive treatment can die.
What is the impact of cutaneous leishmaniasis?
- 600,000-1 million people infected every year
- Endemic in 87 countries
- In 2020 over 85% of new cutaneous leishmaniasis cases occurred in 10 countries: Afghanistan, Algeria, Brazil, Colombia, Iraq, Libya, Pakistan, Peru, the Syrian Arab Republic, and Tunisia
- Effectiveness of current treatments can be as low as 50%
Existing drugs have serious drawbacks in terms of safety, resistance, and availability. The drugs are not well tolerated, have to be taken for a long time, and are difficult to administer.
Pentavalent antimonials (sodium stibogluconate and meglumine antimoniate)
- 21 days of painful intramuscular injections at a hospital or clinic
- 1-2 applications to lesions per week for 3-7 weeks
- Effectiveness in some regions can be as low as 50%
- Toxic, with risk of serious cardiotoxicity leading to death
- Less effective in children under five
- Daily hospital or clinic visits make it difficult for people to access treatment
- Lengthy, arduous treatment has an economic impact on households, often causing caregivers of children with the disease and people from rural areas not to seek treatment or to discontinue treatment prematurely.
- 28-day, twice-a-day oral drug
- Low adherence due to side effects and length of treatment
- Cannot be used during pregnancy
- Developing resistance
- Not available in many countries
- Cannot be used during pregnancy or without contraception among women who can have children
What new treatments for cutaneous leishmaniasis are needed?
Patients need a safe, topical or oral, well tolerated, and affordable treatment that can:
- cure lesions quickly without leaving a deep scar, and
- be deployed within clinics for self-treatment without requiring follow-up by health workers.
In complicated cases, the addition of immunomodulators could enhance the efficacy of antiparasitic drugs.
What cutaneous leishmaniasis treatments are we working on?
We aim to make treatments safer, shorter and more affordable and effective. In the short term, better treatment regimens are being developed using existing treatments. In the long term, the goal is to develop an entirely new generation of all-oral drugs. We are focused on developing treatment for cutaneous leishmaniasis caused by L. tropica and L. braziliensis – because of the severity of these diseases and their impact.
Find out about our work developing treatments for cutaneous leishmaniasis
How do you get cutaneous leishmaniasis?
- Leishmania parasites are transmitted through the bites of infected female phlebotomine sandflies
- Factors that influence people’s risk of infection include poor housing and domestic sanitary conditions; malnutrition; climate and environmental change; and migration
What are the symptoms of cutaneous leishmaniasis?
Cutaneous leishmaniasis can present in different clinical forms, ranging from uncomplicated, self-healing skin lesions to debilitating, large, chronic or recurring lesions, disfiguring mucosal or muco-cutaneous lesions in the mouth or nose, or diffuse cutaneous leishmaniasis. Depending on the form and severity of the disease, cutaneous leishmaniasis can lead to severe social stigma and in some cases disability.
The sores typically progress from small bumps to open lesions with a raised border and central crater – or ulcer – which can be covered with scabs. The lesions usually are painless but can be painful, particularly if open sores become infected with bacteria.
How is cutaneous leishmaniasis diagnosed?
A suspected case of cutaneous leishmaniasis is confirmed by testing for presence of the parasite in the lesion using a variety of techniques. A rapid diagnostic test is commercially available, but it is not widely used and does not perform satisfactorily in all cases.
Last updated: March 2022
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