(See also Introduction to Hypersensitivity Reactions and Inflammatory Skin Disorders Introduction to Hypersensitivity and Inflammatory Skin Disorders The immune system plays a vital role in maintaining the health of all the tissues of the body. The immune system reacts to invaders, such as microorganisms, foreign substances, or cancer cells... read more .)
The cause of granuloma annulare is not clear, but doctors suspect it is the result of an immune system reaction. Many disorders, infections, drugs, and environmental factors have been noticed in people who have granuloma annulare, but having granuloma annulare does not mean that another disorder is present.
Granuloma annulare occurs twice as often in women as in men.
The bumps are usually red but may be slightly bluish, yellowish tan, or the color of the surrounding skin, and a person may have one bump or several. The bumps may be tender but usually cause no pain or itching. They most often form on the feet, legs, hands, or fingers of children and adults. The bumps often expand outwardly to form rings. The center of each ring may be clear or be slightly sunken and sometimes pale or light brown. In some people, the rings become widespread.
Doctors usually diagnose granuloma annulare by its appearance.
A sample of skin may be removed and examined under a microscope (called a skin biopsy Biopsy Doctors can identify many skin disorders simply by looking at the skin. A full skin examination includes examination of the scalp, nails, and mucous membranes. Sometimes the doctor uses a hand-held... read more ) to confirm the diagnosis.
Most often, granuloma annulare heals without any treatment, so people who have no symptoms usually require no treatment. However, healing may take years.
Corticosteroid creams or corticosteroids injected into the rash may help clear it up. Alternatively, tacrolimus may be applied to the skin. Phototherapy Phototherapy Psoriasis is a chronic, recurring disease that causes one or more raised, red patches that have silvery scales and a distinct border between the patch and normal skin. A problem with the immune... read more (exposure to ultraviolet light) and cryotherapy Cold therapy (cryotherapy) Professional rehabilitation therapists treat pain and inflammation. Such treatment makes movement easier and enables people to participate more fully in rehabilitation. Techniques used include... read more (exposure to cold) are other treatments that may also be used.
Hydroxychloroquine, isotretinoin, dapsone, and cyclosporine are other drugs that may be effective if rings are widespread.
Other drugs that suppress the immune system, such as infliximab and adalimumab, may be used to treat granuloma annulare, but they may also trigger the disorder in some people.