Diagnosis: Granuloma annulare
Granuloma annulare is a benign inflammatory skin condition classically described as annular papules and plaques. The lesions typically range from skin-colored to violaceous in appearance. There is no racial predilection for this condition.
There are 4 variants of granuloma annulare:
- The localized form—which our patient had—accounts for approximately 75% of cases.1 Lesions are typically found on the lateral or dorsal surfaces of the hands and feet. Most cases of localized granuloma annulare occur in young adult women.2
- The generalized (disseminated) form involves a number of lesions, and thus, is more widespread (FIGURE 2). Lesions tend to appear on the extremities and the trunk.
- The perforating form is rare, and occurs in both localized and generalized granuloma annulare. Papules may develop into lesions that exude a thick and creamy or clear and viscous fluid.
- The subcutaneous form presents as asymptomatic solitary lesions or in clusters that are most commonly found on the lower extremities—often on pretibial areas. The lesions with this form of granuloma annulare are deeper than the localized form, so there is more swelling, and less surface definition.
Anecdotal reports link condition to diabetes
Although the cause of granuloma annulare is unknown, it has been linked with trauma, thyroid disease, viral infection, malignancy, and diabetes mellitus. Some reports suggest that the lesions are the result of a delayed type hypersensitivity reaction. Of note: Our patient had type 2 diabetes mellitus, something we only discovered while doing a work-up for his lesion. Though largely based on anecdote and case reports, retrospective studies have supported this association.3,4