Primary cutaneous histoplasmosis

Primary cutaneous histoplasmosis is a rare form of histoplasmosis, a fungal infection caused by the Histoplasma capsulatum fungus. This form of histoplasmosis primarily affects the skin, without involving the lungs or other organs as in the more common forms of the disease.

Etiology

Primary cutaneous histoplasmosis is caused by the dimorphic fungus Histoplasma capsulatum. This fungus is found in soil and bird or bat droppings, particularly in certain geographic areas such as the Mississippi River valley and the central United States. Infection occurs when spores of the fungus are inhaled or come into contact with the skin.

Clinical Presentation

Patients with primary cutaneous histoplasmosis typically present with skin lesions that may be ulcerative, verrucous, or nodular in nature. The lesions are often solitary and may be located anywhere on the body, but are most commonly found on the extremities. Unlike disseminated histoplasmosis, patients with primary cutaneous histoplasmosis do not typically have systemic symptoms such as fever, weight loss, or malaise.

Diagnosis

Diagnosis of primary cutaneous histoplasmosis is made through a combination of clinical presentation, histopathological examination of skin biopsy specimens, and culture of the fungus from skin lesions. Immunohistochemistry and molecular diagnostics such as polymerase chain reaction (PCR) may also be used to confirm the diagnosis.

Treatment

Treatment of primary cutaneous histoplasmosis typically involves antifungal medications such as itraconazole or amphotericin B. Surgical excision of skin lesions may also be performed in some cases.

Epidemiology

Primary cutaneous histoplasmosis is a rare disease, with only a small number of cases reported in the medical literature. It can occur in individuals of any age, but is most commonly seen in adults. The disease is more common in individuals who have a history of exposure to soil or bird or bat droppings, particularly in endemic areas.

See Also

• Histoplasmosis
• Cutaneous mycosis
• Fungal diseases