A 50-year-old woman with poorly controlled type 2 diabetes mellitus presents with a widespread eruption of firm, skin-colored to erythematous papules that have coalesced into annular plaques over her trunk and extremities. The lesions are asymptomatic. A biopsy of a papule shows palisading granulomas with necrobiotic collagen and mucin deposition in the upper dermis. What is the most likely diagnosis?
- A Necrobiosis lipoidica
- B Rheumatoid nodule
- C Generalized granuloma annulare ✓
- D Sarcoidosis
Correct answer: C. Generalized granuloma annulare
Explanation
Generalized granuloma annulare presents with widespread, often asymptomatic, skin-colored to erythematous papules forming annular plaques. It is strongly associated with diabetes mellitus, particularly when widespread. Histology shows palisading granulomas with central necrobiotic collagen and mucin. Necrobiosis lipoidica typically occurs on the shins and shows broad bands of necrobiosis. Rheumatoid nodules occur over pressure points. Sarcoidosis shows noncaseating epithelioid granulomas without mucin.
Reference: Andrews' Diseases of the Skin, 13th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.