Granuloma annulare (GA) is a common skin condition of unknown cause. It appears most often over knuckles and other joints or in places that are subject to frequent, mild injury such as the back of the hands or top of the feet. It is seen most often in older children and young adults.
The "rash" of granuloma annulare is symmetrical (appears on both sides of the body more or less evenly) and formed by skin colored bumps. The bumps often expand or join to form rings. The center of each ring may be a little depressed, pale or light brown.
The rash may be confused with ringworm.
Granuloma annulare usually has no other symptoms, but it may be tender. It may come and go, only to return again. Most cases clear up after a few years with or without treatment. Some patients develop multiple rings.
A biopsy may be necessary to confirm the diagnosis.
In most cases, treatment is not required except when the rash causes cosmetic concern. Treatment options include topical corticosteroids, corticosteroid injections, cryotherapy, or ultraviolet light therapy (PUVA).