How To Detect And Treat Granuloma Annulare
- Volume 17 - Issue 12 - December 2004
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Granuloma annulare (GA) is a benign inflammatory, self-limiting granulomatous dermatoses characterized by a variable clinical presentation of dermal and subcutaneous lesions. Although this condition may occur at any age, it is predominantly a disease of children ranging in age from 2 to 10 and adults who are younger than 30. GA is very common in young females as they are twice as likely to be affected than males. Foot involvement occurs in more than 70 percent of all patients with GA and hand involvement occurs in 60 percent of patients.
The lesions may spontaneously resolve in three months to many years, with the average remission occurring two years after onset. Recurrences are common but newer lesions tend to resolve sooner than the original lesions.
The cause of GA is unknown but traditionally has been hypothesized to be related to insect bites, sun exposure, viral infections, diabetes, thyroiditis and certain medications such as antibiotics, antiinflammatory agents and oral contraceptives. However, none of these suggested etiologic factors has been confirmed. Researchers have also proposed the possibility of a hereditary component in some cases but, again, the evidence is weak because of the low numbers of documented cases.
A Closer Look At The Clinical Variants Of Granuloma Annulare
There are several clinical variants of GA including localized GA (classical type), subcutaneous GA, generalized GA (disseminated type), nodular GA and perforating GA.
Localized GA. Localized GA is the most common type and it occurs in both children and young adults under the age of 30. This type is characterized by skin-colored or violaceous, well defined, 1 to 2 mm papules. These papules may expand into larger lesions that are arranged in a complete or half-circle configuration, measuring from 1 to 5 cm in diameter. The lesions are most common on the dorsa of the hands and feet, and on the extensor aspects of the legs. The center of the lesions may be erythematous and slightly depressed relative to their borders. These lesions may be solitary or multiple, with over half of all patients presenting with a single lesion. These lesions may improve in winter and worsen in the summer.
Subcutaneous GA. Subcutaneous GA consists of solitary or multiple asymptomatic lesions measuring 1 to 5 mm in diameter. They may coalesce or expand to several centimeters. The soft tissue masses are usually stable for months but they may enlarge rapidly over a period of a few weeks. Palpation of the lesion reveals small firm granular bodies that are very mobile under the skin. One will commonly see subcutaneous GA on the dorsa of the hands and feet. The most commonly reported site of involvement is the lower extremities (65 percent of all cases). These lesions are often on the pretibial surface and top of the foot. Clinicians may also see this condition on the palms and fingers, legs, buttocks and scalp. The deep dermal lesions are attached to fascia and are often mobile. Some of the larger lesions may be pruritic in nature.