A 20-year-old man presents with alopecia involving more than 50 percent of his scalp. He has failed topical corticosteroids and intralesional injections. Which contact sensitizer is most commonly used as immunotherapy for extensive alopecia areata?

• A Cyclosporine
• B Dinitrochlorobenzene
• C Squaric acid dibutyl ester
• D Diphenylcyclopropenone ✓

Explanation

Diphenylcyclopropenone is the most widely used contact sensitizer for immunotherapy in extensive alopecia areata. It induces allergic contact dermatitis, which alters the local immune response around the hair follicle. Dinitrochlorobenzene is mutagenic and less preferred. Squaric acid is an alternative but less commonly used than DPCP. Cyclosporine is an immunosuppressant, not a contact sensitizer.

Reference: Bolognia Dermatology, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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