B55.1 Cutaneous leishmaniasis

Name of the Condition

• Cutaneous leishmaniasis

Summary

Cutaneous leishmaniasis is a parasitic skin infection caused by Leishmania protozoa. It is transmitted through the bite of infected sandflies and typically presents as localized skin lesions. The condition ranges from self-healing ulcers to chronic, disfiguring sores, depending on the parasite species and host immune response. It is the most common form of leishmaniasis and generally has a better prognosis than visceral or mucocutaneous variants.

Causes

Cutaneous leishmaniasis is caused by Leishmania parasites, which are transmitted to humans through the bite of infected female sandflies of the genus Phlebotomus (Old World) or Lutzomyia (New World). The parasites enter the skin during feeding, multiply within macrophages, and form localized lesions at the site of inoculation. Different Leishmania species are associated with varying clinical presentations and geographic distributions.

Risk Factors

• Exposure to sandfly habitats, such as rural or tropical regions where the insects breed.
• Immunocompromised states, including HIV/AIDS, organ transplantation, or chemotherapy.
• Malnutrition or other conditions that weaken the immune system.
• Travel to or residence in endemic areas, particularly in parts of Asia, Africa, Latin America, and the Mediterranean.

Symptoms

• Painless or mildly painful skin ulcers, often with a raised border, that may heal slowly.
• Lesions typically appear 1–4 weeks after a sandfly bite, starting as papules and progressing to nodules or ulcers.
• Ulcers may be single or multiple, with a dry, crusted base and surrounding erythema.
• Lesions commonly occur on exposed skin, such as the face, arms, or legs.

Diagnosis

Diagnosis is based on clinical presentation, exposure history, and laboratory confirmation. Microscopic examination of lesion scrapings or biopsies may reveal Leishmania amastigotes. Culture, PCR, or serologic testing can also be used to identify the parasite. Histopathology may show granulomatous inflammation with amastigotes in macrophages. In endemic areas, clinical diagnosis may be sufficient, but laboratory confirmation is preferred when available.

Treatment Options

Treatment depends on lesion size, number, location, and species of Leishmania. Small, single lesions may resolve spontaneously without treatment. For larger or multiple lesions, options include topical therapies (e.g., paromomycin ointment) or systemic medications (e.g., pentavalent antimonials, miltefosine). In some cases, cryotherapy or thermotherapy may be used. Treatment duration and choice vary by region and parasite susceptibility.

Prognosis and Follow-Up

Prognosis is generally good, with most lesions healing within months, though scarring or pigment changes may occur. Follow-up is recommended to monitor for healing, recurrence, or progression to mucocutaneous disease. Immunocompromised individuals may experience more severe or prolonged disease and require closer monitoring.

Complications

• Secondary bacterial infection of ulcers.
• Scarring or disfigurement, particularly on visible areas like the face.
• Rarely, progression to mucocutaneous leishmaniasis, which affects mucous membranes.
• Delayed healing in immunocompromised patients.

Lifestyle & Prevention

• Avoid sandfly bites by using insect repellent, wearing protective clothing, and sleeping under insecticide-treated nets.
• Stay in well-screened or air-conditioned accommodations in endemic areas.
• Avoid outdoor activities during peak sandfly activity (dusk to dawn).
• Promptly clean and treat any sandfly bites to reduce infection risk.

When to Seek Professional Help

Seek medical attention if you develop persistent skin ulcers after travel to an endemic area, especially if accompanied by fever, weight loss, or signs of infection. Immunocompromised individuals should seek care promptly, as they are at higher risk for severe disease.

Tips for Medical Coders

Document the specific type of leishmaniasis (cutaneous) and any associated details, such as lesion location, number, or treatment. Ensure the code B55.1 is used for cutaneous leishmaniasis and not confused with other leishmaniasis subtypes. Include exposure history or travel to endemic regions if available, as this supports clinical correlation. Verify that the diagnosis aligns with the code’s definition to ensure accurate coding.