In most cases, granuloma annulare causes no symptoms, or a just mild itch at the start of any new area. It can be tender if knocked.
In most patients, patches occur on only one or two sites of the body, often on bony areas such as the backs of the hand, elbows or ankles. Each patch consists of tiny bumps arranged in a ring.
Typically, the rings slowly grow to 1 or 2 inches across but become flatter and rather more purple in colour as they do so, and then gradually fade. Patients can develop a more widespread rash, but this is rare. A deeper form of the condition, called subcutaneous granuloma annulare, may also occur on rare occasions, particularly in children. It manifests as firm lumps under the skin.
The diagnosis of granuloma annulare is usually based on the appearance of the skin lesions. In some instances, especially in the less common types, a skin biopsy helps to prove the clinical diagnosis. A urine test for sugar is often performed too, as there is a slightly increased risk of diabetes for those with the less common, widespread type of granuloma annulare.
Granuloma annulare usually goes away by itself in about 2 years after onset; however, this cannot be predicted accurately on an individual basis.