Kornel disease (cutaneous leishmaniasis) - Causes, Treatment & When to See a Doctor

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What is Kornel disease (cutaneous leishmaniasis)?

Kornel disease, more correctly called cutaneous leishmaniasis (CL), is a skin infection caused by protozoan parasites of the genus Leishmania. The disease is transmitted to humans through the bite of infected female sand‑flies (family Psychodidae). Once the parasite inoculates the skin, it multiplies within macrophages, leading to a slowly evolving skin lesion that can become ulcerative, disfiguring, or scar‑forming if left untreated.

The term “Kornel disease” is used primarily in some Eastern European literature and refers to the same clinical entity as CL. The condition is endemic in parts of the Middle East, Central and South America, the Mediterranean basin, and some regions of Asia and Africa. Although it is not typically life‑threatening, the cosmetic and psychosocial impact can be considerable, especially when lesions appear on the face or exposed areas.

Common Causes

Cutaneous leishmaniasis is not a single disease but a group of infections caused by several Leishmania species. The most frequent causative agents and related risk factors include:

• Leishmania major – common in Africa and the Middle East.
• Leishmania tropica – found in urban areas of the Middle East and Central Asia.
• Leishmania mexicana – endemic in Mexico, Central America, and parts of South America.
• Leishmania braziliensis – associated with mucocutaneous complications in South America.
• Leishmania infantum (L. chagasi) – can cause both cutaneous and visceral disease in the Mediterranean and Latin America.
• Living or traveling in endemic regions where sand‑flies thrive (dry, warm climates with sandy soil).
• Outdoor occupations or activities (farming, construction, military service) that increase exposure to sand‑fly bites.
• Living in poor‑quality housing with cracks or cracks in walls where sand‑flies rest.
• Immunosuppression (e.g., HIV infection, organ transplantation, systemic steroids) – can worsen lesion size and healing.
• Travel to endemic areas without protective measures – tourists and migrant workers are increasingly reported.

Associated Symptoms

While the primary manifestation is a skin lesion, patients often experience additional signs:

• Initial papule or nodule: a small, painless bump appears 1‑4 weeks after the bite.
• Ulceration: the papule can enlarge, become crusted, and develop a central ulcer with raised, indurated margins.
• Redness & swelling around the lesion.
• Satellite lesions – new nodules may develop nearby.
• Regional lymphadenopathy – tender lymph nodes close to the lesion, especially in L. braziliensis infection.
• Pruritus or burning sensation during lesion development.
• Scarring after healing, which can be hypertrophic or atrophic.
• Secondary bacterial infection – indicated by increased pain, purulent discharge, or expanding erythema.

When to See a Doctor

Prompt evaluation is essential to avoid complications and reduce scarring. Seek medical attention if you notice any of the following:

• New skin lesion that does not heal within 2–4 weeks, especially after travel to an endemic area.
• Lesion that is enlarging, ulcerating, or becoming painful.
• Signs of infection (pus, increasing redness, warmth, fever).
• Multiple lesions appearing simultaneously.
• Lesions located on the face, eyelids, or near mucosal surfaces.
• History of immunosuppression combined with a skin lesion.
• Any suspicion of mucocutaneous leishmaniasis (nasal or oral ulceration) – requires urgent care.

Diagnosis

Diagnosing cutaneous leishmaniasis involves a combination of clinical suspicion, travel/ exposure history, and laboratory confirmation.

1. Clinical Evaluation

• Detailed history of travel, residence, or work in endemic regions.
• Physical examination of the lesion’s size, shape, border, and base.
• Assessment for lymphadenopathy or mucosal involvement.

2. Laboratory Tests

• Skin scrape or biopsy – tissue is examined under microscopy after staining (Giemsa) to detect amastigotes (Leishman‑Donovan bodies).
• Culture – inoculation of lesion material into specialized media (Novy-MacNeal-Nicolle) to grow the parasite.
• Polymerase chain reaction (PCR) – highly sensitive DNA test that identifies the specific Leishmania species, guiding therapy.
• Serology – limited utility for cutaneous disease but may aid in differentiating visceral involvement.
• Montenegro skin test (Leishmanin test) – intradermal delayed‑type hypersensitivity test; a positive result supports exposure but not active disease.

3. Imaging (Rare)

In cases where mucocutaneous disease is suspected, CT or MRI of the nasal cavity and sinuses may be ordered to assess tissue destruction.

Treatment Options

Treatment decisions depend on lesion size, location, species, patient immune status, and drug availability. The goal is to eradicate the parasite, accelerate healing, and minimize scarring.

1. Systemic Antileishmanial Medications

• Miltefosine (oral) – effective for many Old World species; usual dose 2.5 mg/kg/day for 28 days (FDA‑approved for leishmaniasis). Side effects: gastrointestinal upset, teratogenicity – not for pregnant women.
• Liposomal Amphotericin B – intravenous; preferred for L. braziliensis or immunocompromised patients. Dose: 3 mg/kg on days 1‑5, 10, 17, 24 (total 21 mg/kg).
• Pentavalent antimonials (e.g., Sodium Stibogluconate, Meglumine Antimoniate) – once the mainstay, now less used due to toxicity (cardiotoxicity, pancreatitis). Given 20 mg Sb⁵⁺/kg/day for 20‑30 days.
• Paromomycin (topical or intralesional) – an aminoglycoside that can be applied as a cream (15 % concentration) or injected directly into the lesion.

2. Local Therapies (for small, uncomplicated lesions)

• Cryotherapy – liquid nitrogen applied 2‑3 times weekly until the lesion resolves.
• Heat therapy – localized heating to 50‑55 °C for 30 seconds, repeated weekly; effective for many Old World species.
• Topical azoles (e.g., ketoconazole) – limited evidence; sometimes used as adjuncts.
• Intralesional antimonials – injection directly into the lesion (5‑10 mg Sb⁵⁺/ml) weekly for 3‑6 weeks.

3. Supportive & Home Care

• Keep the lesion clean; gentle washing with mild soap and water.
• Apply a sterile non‑adherent dressing to prevent secondary bacterial infection.
• Use over‑the‑counter analgesics (acetaminophen or ibuprofen) for discomfort.
• Avoid scratching or picking at the ulcer – this can worsen scarring.
• Sun protection (broad‑spectrum SPF 30+) once the lesion begins to heal, as UV exposure can darken scars.

4. Follow‑Up

Patients should be re‑evaluated 2‑4 weeks after initiating therapy to document response and adjust treatment if healing is inadequate. Most lesions improve within 4‑12 weeks of appropriate therapy.

Prevention Tips

Because infection requires a sand‑fly bite, preventive measures focus on vector control and personal protection:

• Use insect repellent containing DEET (20‑30 %), picaridin, or IR3535 on exposed skin.
• Wear protective clothing – long sleeves, long pants, and socks, especially during dusk and dawn when sand‑flies are most active.
• Sleep under insecticide‑treated bed nets if staying in endemic rural areas.
• Apply indoor residual spraying or use window screens to reduce indoor sand‑fly entry.
• Avoid outdoor activities during peak sand‑fly activity (dusk to early night).
• Environmental management: clear leaf litter, keep yards free of dog and rodent burrows, and use sand‑fly insecticide traps where appropriate.
• Travel advice: consult travel clinics before visiting endemic regions; they can prescribe prophylactic repellent and give region‑specific recommendations.
• Vaccination – currently no licensed vaccine for human CL, but ongoing research may change this in the future.

Emergency Warning Signs

Key Take‑aways

• Kornel disease is another name for cutaneous leishmaniasis, a parasitic skin infection transmitted by sand‑fly bites.
• It is endemic in many warm, arid regions; travel or residence in these areas is the main risk factor.
• Typical lesions begin as painless papules and may evolve into ulcerated sores that can scar.
• Diagnosis requires laboratory confirmation (microscopy, culture, PCR) plus a thorough exposure history.
• Treatment ranges from topical/local therapies for small lesions to systemic agents such as miltefosine or liposomal amphotericin B for larger or mucocutaneous disease.
• Prevention hinges on sand‑fly bite avoidance: repellents, protective clothing, bed nets, and environmental control.
• Seek immediate medical attention for signs of secondary infection, mucosal involvement, or severe drug reactions.

For up‑to‑date guidance, consult reputable sources such as the CDC, Mayo Clinic, and the World Health Organization. Always discuss individual cases with a qualified healthcare professional.

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