Risk factors for intraoperative immediate-type hypersensitivity reactions may require allergological evaluation. We report the case of a hairdresser with a positive history of penicillin hypersensitivity and anaphylactic shock during previous general anesthesia, whose in vivo and in vitro allergy tests were positive for neuromuscular blocking agents, opioids, and midazolam. Immediate-type hypersensitivity reactions to antibiotics and professional exposure to hairdressing products might induce simultaneous cross-sensitization to multiple drugs that are commonly used during general anesthesia.