Kimura disease is a rare, noncancerous, chronic condition that causes the tissue under the skin of the head or neck to become swollen. Masses generally appear in a person's mid-20s and the disease mainly affects Asian men. Kimura disease is diagnosed by a surgical biopsy and the cause of the disease is unknown. Treatment includes surgery, medication, or a combination of the two. However, the masses tend to develop again after treatment. Because this condition rarely causes health problems, people with Kimura disease have a good outcome.

The cause of Kimura disease is unknown, but it appears to be due to an abnormal immune response.

Masses on the head and neck usually appear in a person's late 20s to early 30s. Most individuals with Kimura disease have no other symptoms. The masses are not painful, but may get bigger over time without treatment. About 20 to 60 percent of people with Kimura disease have kidney disease including nephrotic syndrome (increased protein in the urine).

Kimura disease can be diagnosed by a surgical biopsy. Diagnosis is important because Kimura disease can look like other more serious conditions such as other immune system disorders, drug reactions, infections, or specific types of cancer.

There is no cure for Kimura disease, but surgery or medications can be used to remove or shrink the masses. Surgery followed by low dose radiation therapy appears to be the treatment resulting in the longest period of remission. Radiation therapy alone has also been used to treat the masses seen in Kimura disease. Steroids (such as prednisone), taken by mouth or via an injection in the skin, can shrink the masses but the mass often reappears after treatment is stopped. Steroids can also be used to treat the kidney disease. Other, less common, treatments include medications that decrease swelling and increase blood flow (such as oral pentoxifylline), medications that suppress the immune system (such as cyclosporine), radiotherapy, and a combination of several medications and steroids.

Individuals with Kimura disease should be followed to watch for the recurrence of the masses and for kidney disease. Kimura disease has not been associated with cancer or an increased risk for cancer. Masses are not painful or associated with other symptoms, but they can significantly affect the appearance of the face and neck or cause dental issues.