A 24-year-old woman presents with recurrent tender dusky-red nodules on the posterior aspect of both lower legs during winter. Some nodules ulcerate and heal with depressed scars. She has a history of treated pulmonary tuberculosis. Biopsy shows lobular panniculitis with granulomatous inflammation. The most likely diagnosis is:

• A Erythema nodosum
• B Polyarteritis nodosa
• C Papulonecrotic tuberculid
• D Erythema induratum of Bazin ✓

Explanation

Erythema induratum of Bazin is a nodular tuberculid presenting as recurrent tender violaceous nodules on the posterior calves of young women, often ulcerating and healing with scars, classically worse in winter. Histology shows lobular panniculitis with granulomas and vasculitis. Erythema nodosum occurs on the shins, does not ulcerate, and heals without scarring. Papulonecrotic tuberculid presents as necrotic papules over extensor surfaces rather than calf nodules.

Reference: Rook's Textbook of Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.