Granuloma annulare is a chronic skin disease consisting of a rash with reddish bumps arranged in a circle or ring. Granuloma annulare is caused by inflammation in the dermis and is different from warts. It most often affects children, young and older adults and it is slightly more common in females (60/40 ratio).
The cndition is usually seen in otherwise healthy people. Occasionally, it may be associated with diabetes or thyroid disease. It has also been associated with auto-immune diseases such as systemic lupus erythematosus. The cause of granuloma annulare is currently unknown.
Aside from the visible rash, granuloma annulare is usually asymptomatic. Sometimes the rash may burn or itch. Patients usually notice a ring of small, firm bumps (papules) over the backs of the forearms, hands or feet, often centered around joints or knuckles. The bumps are caused by the clustering of T cells below the skin. Occasionally, multiple rings may be found. Rarely, granuloma annulare may appear as a firm nodule under the skin of the arms or legs. It also occurs on the sides and circumferential at the waist and without therapy can continue to be present for many years. Outbreaks continue to develop at the edges of the aging rings.