Generalized granuloma annulare (GGA), also known as disseminated granuloma annulare, is characterized by widespread papules and/or annular plaques made up of firm, pink or skin-colored papules. These lesions are usually asymptomatic or only mildly pruritic. While granuloma annulare can present with more localized variants, the generalized form may involve any area of the body, most commonly the trunk and extremities. Often, these lesions have a predilection for the skin folds (ie, axillae and groin). Rarely, mucocutaneous involvement can occur.

In contrast to other variants of granuloma annulare, the generalized form has a bimodal distribution, predominantly affects children younger than 10 years and adults older than 40 years, has a more prolonged course, and is more resistant to treatment. Granuloma annulare does not favor any particular ethnicity or region. Disseminated disease occurs in approximately 15% of patients with granuloma annulare, with a greater incidence in females than males.

Although the etiology of granuloma annulare is poorly understood, there are rare reports of associations with infections, systemic diseases, hematologic malignancies, and solid tumor malignancies. In particular, hypothesized infectious associations are tuberculosis, HIV, Epstein-Barr virus, hepatitis B and C virus, and herpes zoster virus. Systemic diseases reported to have a connection with granuloma annulare are diabetes mellitus (see type 1, type 2) and thyroid disease. Chronic stress has been reported as a trigger. There have also been cases of granuloma annulare following trauma or insect bites. Familial cases have led to the hypothesis of an association with specific human leukocyte antigen (HLA) phenotypes. While these factors all may be initiators of granuloma annulare, the mechanism of lesion formation has many possibilities. Current hypotheses include a delayed-type hypersensitivity reaction, a cell-mediated immune response, a cytokine-mediated breakdown of connective tissue, or a primary degeneration of connective tissue with an ensuing granulomatous inflammation.