Granuloma Annulare (GA)

Granuloma annulare is a common skin problem for which several clinical variants exist. The two most common variants are the localized form and the generalized form. Other clinical variants include micropapular, nodular, linear, perforating, patch or interstitial, and deep forms. Females are more commonly affected than males. Granuloma annulare can occur in any age group, but the localized form is usually seen in patients in the first three decades of life while the generalized form is seen in patients in the fourth through seventh decades. The cause of GA is unknown.

In the two most common forms of GA, localized and generalized, the lesions are flesh to pink to violaceous bumps or plaques. Most frequently the lesion assumes a ring-shaped or annular configuration that tends to enlarge centrifugally. Rarely, the rings over 5 cm in diameter may be observed. In the localized form, the lesions appear mainly over the joints on hands and fingers, arms and ankles.

In the generalized form, there may be hundreds to thousands of small red or tan bumps in a symmetric distribution on the trunk and extremities. Diabetes may be increased in the generalized form. Upon healing, the red color turns to brown before the lesions eventually disappear. Granuloma annulare does not lead to scar formation and it usually has no symptoms.

Granuloma annulare can resolve spontaneously without treatment after months to several years (within two years in half of the cases) and therefore observation and reassurance may be the treatment of choice. Topical corticosteroids with our without occlusion or intralesional corticosteroid injections are sometimes beneficial in localized GA. Various oral medications have been tried with varied success in the generalized form and are reserved for severe cases.

Smith MD, Downie JB, DiCostanzo D. Granuloma annulare. Int J Dermatol 1997;36:326.
Muhlbauer JE. Granuloma annulare. J Am Acad Dermatol. 1980;3:217-30.

Celeste Angel, D.O.
Department of Dermatology
Philadelphia College of Osteopathic Medicine/Frankford Hospital
Philadelphia, Pennsylvannia