How do cutaneous, visceral, and mucocutaneous leishmaniasis differ?

Leishmaniasis is a group of diseases caused by protozoan parasites of the genus Leishmania, transmitted to humans by the bite of infected sand flies. The three major forms differ primarily in the location of the infection and the severity of the symptoms.12

• Cutaneous Leishmaniasis: This is the most common form. The parasites remain localized at the site of the bite, typically on the face, hands, or legs, where they cause skin lesions that often develop into ulcers. These sores may last for months or years before healing, often leaving permanent scars.312
• Visceral Leishmaniasis (Kala-azar): This systemic and potentially fatal form occurs when infected macrophages carry the parasite through the blood to internal organs, primarily the liver, spleen, and bone marrow. Symptoms include fever, weight loss, anemia, and significant enlargement of the liver and spleen.124
• Mucocutaneous Leishmaniasis: Often a complication of New World cutaneous infections, this form occurs when the parasite spreads from the initial skin site to the mucous membranes of the nose, mouth, and throat. It can lead to severe tissue destruction in these areas.12