Aetiology

• the aetiology is unknown. There are reports of granuloma annulare following trauma, malignancy, viral infections (including Herpes zoster, Epstein-Barr virus and HIV), skin bites and tuberculosis skin tests(1)
• association with diabetes mellitus is controversial
• condition is usually sporadic, but familial cases have been reported(2)

Reference:

• 1 Cyr PR. Diagnosis and Management of Granuloma Annulare. Am Fam Physician 2006;74:1729-34
• 2. Whelan JP, Zembovicz A. Case 19-2006 - A 22-Month-Old Boy with the Rapid Growth Subcutaneous Nodules. N Engl J Med. 2006;354(25):2697- 2704.