Sarcoidosis is characterized by granulomas (a mass of red, irritated tissue) that may affect any organ system. The disease most commonly involves granuloma formation in the lungs. Other commonly involved organ systems include the lymph nodes, skin, eyes, liver, heart, nervous, musculoskeletal, renal (kidney), and endocrine systems.

Signs and symptoms of sarcoidosis are variable because of its ability to affect multiple organ systems. The skin is involved in 25% of sarcoidosis patients. Skin lesions are round to oval, reddish brown to purple, tender and firm. They may appear after a few days and last several months.

The exact cause of sarcoidosis is unknown. Genetic and environmental factors are suspected to play a part in the disease.

A biopsy of the affected area of skin is required for diagnosis of sarcoidosis. In addition to this simple procedure, a physician may order some blood tests and x-rays depending on the severity of the disease.

Treatment of sarcoidosis depends on the symptoms and organ systems involved for each individual patient. Limited, non-disfiguring skin lesions may be treated with topical or intralesional corticosteroids. For more advanced and chronic lesions immunosuppressants like methotrexate and azathioprine may be used. Surgical removal of the lesions may be attempted but they may come back. Other clinicians like an ophthalmologist, internist, and pulmonologist should be involved in the treatment and monitoring.