Red Man Syndrome is most closely associated with which antibiotic?

• A. Allergic reaction to penicillin
• B. Heat rash
• C. Pruritus with erythematous rash due to vancomycin
• D. IgE-mediated anaphylaxis

Answer: (C)

Red Man Syndrome is an infusion-related reaction caused by rapid IV vancomycin, due to histamine release from mast cells rather than an IgE-mediated allergy. It presents as pruritus with an erythematous, flushing rash—often on the face, neck, and upper chest—moderately distinct from true allergic reactions. Because it stems from the rate of infusion, slowing the vancomycin administration (and giving an antihistamine if needed) typically resolves the symptoms. This is not an IgE-mediated anaphylaxis and does not reflect a penicillin allergy; the rash described in Red Man Syndrome specifically points to vancomycin-related histamine release rather than a classic drug allergy.