Occupational Anaphylaxis to Piperacillin-Tazobactam in a Nurse: A Case Report.

Piperacillin-tazobactam is a widely used β-lactam antibiotic, yet occupational systemic anaphylaxis remains exceptionally rare. We report the case of a 26-year-old female nurse with persistent atopic dermatitis and previous history of allergic contact dermatitis to nickel and cobalt, who developed occupational anaphylaxis while preparing intravenous cefuroxime and piperacillin-tazobactam. She presented with acute erythematous papules, rhinorrhea, wheezing, dyspnea, and tachycardia, requiring treatment with intramuscular epinephrine, intravenous clemastine, and hydrocortisone, with complete clinical resolution. She later tolerated cefuroxime handling but developed a generalized rash following accidental skin contact with piperacillin-tazobactam powder. No cofactors were identified, and no reactions occurred outside the workplace. Skin prick testing was performed and elicited an exuberant positive response, with a wheal >20 mm, marked erythema, pruritus, and satellite vesicles after 15 minutes. Additional work-up showed positive specific IgE to penicilloyl G and amoxicillin, with negative latex and formaldehyde testing and normal baseline tryptase. This case supports piperacillin-tazobactam as a potential occupational allergen capable of inducing severe IgE-mediated reactions through non-therapeutic exposure, possibly via inhalation or skin contact during drug reconstitution. Early recognition, diagnostic confirmation, exposure avoidance, and workplace adjustments are essential to prevent recurrent reactions and reduce the risk of occupational disability. In selected cases transfer to a low-exposure work environment may be required. This case reinforces that non-therapeutic occupational exposure to piperacillin-tazobactam can lead to life-threatening IgE-mediated anaphylaxis, highlighting the need for increased awareness and structured preventive strategies in healthcare settings.