1. Distribution: dorsal feet and hands; elbows and ankles

2. Annular configuration

3. Slowly evolving shapes and sizes

4. Violaceous color

Clinical Presentation

The primary lesion of granuloma annulare is a nonscaIing, dome-shaped or slightly flattened papule 3 to 6 mm in diameter. These papules may be skin colored, pink, or violaceous. Lesions on the lower extremities are more darkly colored than those located elsewhere. The multiple papules of granuloma annulare are typically arranged in the form of a ring. The size of these rings ranges from 1 to 8 cm in diameter. The individual papules that make up the border are closely set but may not be completely confluent. This can give a "beaded" appearance to the border. The depressed center of the ring is sometimes darker than the papular edge. Multiple rings are present in about half of the patients. Adjacent rings may grow together, forming a single larger lesion with a polycyclic configuration.

Lesions are most commonly found on the dorsal surface of the feet and on the dorsal surface of the hands and fingers. The extensor surfaces of the arms and legs (to include the elbows and knees) are also fairly frequently involved. Granuloma annulare occurs at any age, but the peak incidence occurs in children aged 4 to 12 years. Lesions are asymptomatic. A clinical diagnosis can be confirmed by biopsy.

Atypical clinical Presentations

Occasionally, adults will develop a disseminated pattern consisting of hundreds of small rings. The entire body may be involved, but there may be some predilection for sun-exposed surfaces. Subcutaneous lesions resembling rheumatoid nodules are occasionally seen in children. Very rarely, papules and nodules of granuloma annulare undergo ulceration (perforating granuloma annular). On some occasions, granuloma annulare simulates the appearance of necrobiosis lipoidica diabeticomm (NLD) to point where the two diseases cannot be distinguished either clinically or histologically.

Course and Prognosis

Individual ringed lesions grow in diameter and sometimes challge shapes over a period of weeks to months. The course of the disease is selflimited, and usually within 1 or 2 years trace of the lesions has disappeared.

Controversy exists as to whether or not there is a updationship between granuloma annulare and diabetes mellitus, most evidence favors the lack of a relationship.

Pathogenesis

The cause of granuloma annulare is unknown. The lesions histologically somewhat similar to those of NLD and rheumatoid nodules. Moreover, clinical overlap between gl"anuloma annulare and NLD certainly occurs. The significance of these observations is unknown. The location of granuloma annulare on the hands and feet and an occasional distribution on sun-exposed skin suggest that trauma of some sort plays an etiologic role. New lesions cannot experimentally be induced in this way, however. In fact, nonspecific truma, such as saline injections, sometimes causes resolution in established lesions. A role for immune complex formation and cells-immediated immune response in the pathogenesis of granuloma annulare has been suggested by some studies.

Therapy

There is no dependably effective treatment for granuloma annulare, Lesions may respond to high-potency topical steroids specially when they are used with occlusion, intralesionally injected steroids are somewhat more effective. Discomfort during injection and the development of postinjection atrophy, however, limit the usefulness of this latter approach. A number of other therapies including the use of psoralens-long-wave­length ultraviolet light (PUV A) and systemically administered chlorambucil and dapsone have been suggested, but proof of dlicacy has not been established.