Concomitant Subtypes of Granuloma Annulare in a 66-Year-Old Female: A Case Report.

Granuloma annulare (GA) is a benign, self-limited inflammatory skin condition with an unknown etiology. Although it usually presents with characteristic clinical features, a biopsy may be necessary in atypical cases to differentiate it from other granulomatous diseases. We describe a case of a 66-year-old female with two concomitant subtypes of GA, presenting with distinct clinical features but exhibiting similar histopathological findings. The patient had extensive, pruritic erythematous-violaceous lesions on her lower abdomen, buttocks, and proximal thighs, which had been progressing over the course of one year. Biopsies from the abdominal and thigh lesions showed typical histopathological features of GA, with mucin deposition, histiocytic infiltrate, and granulomatous formations. Treatment with oral antihistamines and medium-potency topical corticosteroids effectively controlled the itching but did not alter the lesion's appearance. Five months later, the patient developed new, pruritic, skin-colored, confluent papules on the internal face of her left arm, and a subsequent biopsy confirmed annular GA. Although the patient did not follow the prescribed dapsone treatment, the lesions spontaneously regressed within a year. This case emphasizes the importance of recognizing less common presentations of GA, which can mimic other, more concerning conditions. While various therapeutic options have been explored, none guarantee complete remission; however, GA typically resolves on its own over time. A better understanding of the disease's pathogenesis and the development of targeted treatments are warranted to improve management strategies for GA.