Granuloma annulare and autoimmune thyroiditis in primary care: A case report

Abstract

INTRODUCTION: Granuloma annulare (GA) is a benign, self-limiting, skin condition of unknown cause. Disease associations have been reported, however limited evidence exists exploring the significance of the associations. GA may be caused by trauma, insect bites, tuberculosis skin tests, or various viral infections. Due to similarity of appearance to other skin conditions with round lesions, clinicians should be aware of GA and its typical clinical manifestation. PURPOSE: Describe a case of generalized GA associated with autoimmune thyroiditis in a 62-year old female and review the etiology, clinical presentation, diagnosis, patient-specific screening, and treatment of localized and generalized GA. CASE PRESENTATION: A 62-year old female with hypothyroidism presented with multiple red, round lesions of varying size distributed on her elbow, hand, legs, and ankle; lesions were present for two years. She was diagnosed with tinea corporis ("ring-worm") by other providers but antifungal treatment was ineffective. Her diagnosis of generalized GA was made via biopsy at the outpatient clinic and treated with a topical steroid cream. Follow-up was advised. DISCUSSION: The cause of GA is unknown. Lesions are characteristically annular, red, non-itchy, and smooth. Among the various subtypes, localized GA is the most common clinical presentation followed by generalized GA. Diagnosis can be made clinically or with biopsy. Attention to other underlying causes is warranted, so additional laboratory tests may be appropriate in specific cases. No treatment guidelines currently exist but topical and intralesional steroids are the mainstay of treatment for localized GA. However, hydroxychloroquine (Plaquenil®), a medication used to treat rheumatoid arthritis, lupus, and malaria, may be first line treatment for generalized GA. CONCLUSION: GA is a self-limited skin condition of unknown cause diagnosed by clinical presentation or biopsy and treated with topical steroids. GA should be considered in the differential diagnosis for patients with smooth, red, round lesions, especially if the patient has a history of autoimmune thyroiditis.