A 26-year-old Turkish man reports recurrent painful oral aphthae occurring more than three times yearly for five years, recurrent genital ulcers leaving scars, and tender red nodules on his shins. A needle prick on the forearm produces a papulopustular lesion at 48 hours. What is the most likely diagnosis?

• A Behcet disease ✓
• B Sweet syndrome
• C Erythema multiforme
• D Herpes simplex infection

Explanation

Recurrent oral aphthae are the mandatory feature of Behcet disease, and the combination with genital scarring ulcers, erythema nodosum-like lesions, and a positive pathergy test satisfies international diagnostic criteria. Pathergy, an exaggerated nonspecific skin hyperreactivity to prick injury, is characteristic of Behcet disease and also of pyoderma gangrenosum. Herpes simplex causes grouped vesicles that culture positive, while Sweet syndrome presents as oedematous plaques with fever and neutrophilia rather than recurrent aphthae.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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