Round plaques like this one, each composed of many small erythematous papules, are classic for granuloma annulare. Large numbers of these lesions and widespread distribution is often associated with diabetes mellitus.
A 53-year-old woman complained about the sudden onset of a widespread itchy rash.
Key points: Physical examination disclosed innumerable annular (round) plaques, each composed of many small, erythematous papules. This is classic for granuloma annulare (GA). In this case, because of the large numbers of such lesions and widespread anatomic distribution, this would be called disseminated granuloma annulare.
Treatment: Because of the failure of topical and intralesional corticosteroids, the patient was treated with weekly exposures to an excimer laser (solitary wavelength 308 nm). Plaques gradually faded and itching subsided.
Note: Disseminated GA is often associated with diabetes mellitus. The patient was found to have elevated fasting and 2-hour postprandial blood glucose levels, as well as a markedly elevated hemoglobin A1c (8.5%).