What Are the Causes of Granuloma Annulare?

The ultimate causes of granuloma annulare are not known, but the condition is sometimes triggered by sun exposure, insect bites, tuberculin skin tests, vaccinations or infection, according to MayoClinic.org. Granuloma annulare is also sometimes found in association with diabetes thyroid disease, in which case it is usually widespread.

Granuloma annulare is a skin condition that manifests as rings of bumps that can be either colored like the surrounding skin or ruddy brown, MayoClinic.org says. These bumps most often appear on the hands and feet. There is more than one type of granuloma annulare, and different types most frequently affect different age groups. The condition does not usually cause pain or physical discomfort, and so the need for treatment is minimal. Any bumps usually go away on their own within two years, although medications can speed this process if they affect a person's appearance negatively.

It has been associated with other autoimmune diseases, such as systemic lupus erythematosus, Addison's disease and rheumatoid arthritis. Granuloma annulare is sometimes associated with other diseases, such as diabetes and thyroid disease.

The most common type of granuloma annulare is a localized manifestation, according to MayoClinic.org. These usually show up as circular or semicircular groups of bumps on the hands, feet, wrists or ankles, and are most common in young women. Generalized granuloma annulare is more common in adults, can cover a large amount of the body, and is more likely to itch. The subcutaneous form is most common in children, and causes firm lumps beneath the skin rather than on the surface.

The rash may disappear faster if treated with strong steroid creams and ointments. Other treatment options include direct injections of steroids on the rash, and freezing the bumps with liquid nitrogen.