Granuloma annulare is a skin condition that begins with red, smooth, ring-shaped lesions that can enlarge to form patches, which may be tender. The patches of granuloma annulare can occur anywhere over the body, but areas of minor trauma and constant friction, such as the backs of hands and feet, knees, and elbows are most frequently affected. What causes granuloma annulare remains unknown.
Who's At Risk
Granuloma annulare is most common in young children and teens, though it can occur in anyone. Females are more likely to be affected. Granuloma annulare also tends to occur within family members. Trauma, viruses, sun exposure, and specific drugs (such as allopurinol) have all been thought to predispose a person to developing this rash, though this has not been confirmed.
Signs and Symptoms
Granuloma annulare occurs most frequently over the joints or in areas that experience mild injury. The most common locations for granuloma annulare include:
- Backs of the hands and tops of the fingers
- Tops of the feet
- Around the elbows
- Around the knees
The lesions of granuloma annulare are usually found in the same areas on both sides of the body (symmetrically).
Granuloma annulare appears as small (1–3 mm), skin-colored or pink bumps. These bumps, which are smooth rather than scaly, may occur singly or in groups. Each bump may expand in size, leaving a shallow indentation in the center, which may be lighter or darker than your normal skin. Alternatively, several small bumps may merge to form a ring, 1–5 cm in diameter. Healed lesions of granuloma annulare do not leave scars.
Granuloma annulare does not usually have any symptoms, though some individuals may experience itching.
Rarely, granuloma annulare may be widespread, known as generalized granuloma annulare. Generalized granuloma annulare tends to appear in adults over 30 years old. The condition may consist of hundreds to thousands of 1–2 mm bumps, which appear on the arms, legs, and upper trunk. These skin-colored or pink bumps may be quite itchy.
Because granuloma annulare does not usually have symptoms, it may go unnoticed for many months. If, however, the lesions are itchy, an over-the-counter cortisone cream may be helpful.
When to Seek Medical Care
If you have bumps or ring-shaped lesions on your skin for more than several weeks, it is probably a good idea to have them evaluated by a dermatologist or by another health care provider who can distinguish them from conditions such as ringworm or insect bites, including Lyme disease.
Treatments Your Physician May Prescribe
If the diagnosis of granuloma annulare is not obvious, the doctor may want to perform a skin biopsy. The procedure involves:
- Numbing the skin with an injectable anesthetic.
- Sampling a small piece of skin by using a flexible razor blade, a scalpel, or a tiny cookie cutter (called a "punch biopsy"). If a punch biopsy is taken, a stitch (suture) or two may be placed and will need to be removed 6–14 days later.
- Having the skin sample examined under the microscope by a specially trained physician (dermatopathologist).
Once the diagnosis of granuloma annulare is confirmed, you and your physician may decide not to treat it. Up to 70% of cases of granuloma annulare go away by themselves (spontaneous resolution) within 2 years, even without treatment. However, up to 40% of people may experience a return of the lesions (recurrence), usually at the same sites of the original rash.
If the lesions of granuloma annulare are uncomfortable or unsightly, the physician may recommend one of the following:
- A prescription-strength steroid or cortisone cream
- Steroid injections directly into the lesions
- Freezing with liquid nitrogen (cryosurgery)
- Non-steroid topical anti-inflammatory creams such as tacrolimus or pimecrolimus
- Treatment with carbon dioxide laser
Generalized granuloma annulare is more stubborn, with fewer cases of spontaneous resolution and more recurrences. In addition, more aggressive medications may be used:
- Oral steroids, such as prednisone
- Oral retinoids, such as isotretinoin
- Ultraviolet light
- Other oral medications such as potassium iodide, dapsone, nicotinamide, pentoxifylline, hydroxychloroquine, or cyclosporine
Bolognia, Jean L., ed. Dermatology
, pp.1460-1463. New York: Mosby, 2003.
Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine
ed, pp.980-984. New York: McGraw-Hill, 2003.