A102-18 A Critical Care Cascade: Iatrogenic Systemic Botulism Complicated by Biphasic Anaphylaxis and Airway Compromise

Background Botulism is a rare but serious neuroparalytic syndrome caused by botulinum neurotoxin. Although Clostridium botulinum infection is the classic source, systemic botulism can rarely occur after therapeutic or cosmetic botulinum toxin injection. The FDA warns that onabotulinumtoxinA (Botox) may spread beyond the injection site, causing generalized weakness, dysphagia, and respiratory failure. Despite widespread use, confirmed systemic cases in the United States remain exceedingly rare. Case Presentation A 40-year-old woman with chronic migraine presented with one day of blurred vision, diplopia, dysphagia, slurred speech, and upper-extremity weakness. One day earlier, she had received cosmetic botulinum toxin injections; twelve weeks before, she had undergone Botox therapy for migraine prophylaxis. Neurologic exam revealed bilateral ophthalmoplegia, dysarthria, and symmetric proximal weakness (2/5). Imaging excluded stroke. Electrodiagnostic studies showed low compound muscle action potentials and a decremental response on low-frequency stimulation, consistent with a presynaptic neuromuscular junction disorder. Serum botulinum toxin testing was not performed, but the combination of clinical features, EMG findings, and recent exposure supported the diagnosis of iatrogenic botulism. She received botulinum antitoxin (BAT) promptly. Fifteen minutes into the infusion, she developed urticaria, lip swelling, and wheezing consistent with anaphylaxis. The infusion was stopped, and intramuscular epinephrine was administered with resolution. Two hours later, she experienced recurrent anaphylaxis requiring repeat epinephrine. Subsequently, her voice became hoarse with drooling and poor secretion control. Concern for progressive laryngeal edema prompted elective intubation for airway protection. She was treated with nebulized epinephrine and intravenous dexamethasone. ICU course was complicated by aspiration pneumonia, but she improved gradually and was extubated on day 3. Over two weeks, her bulbar and limb weakness resolved, and she was discharged to rehabilitation. Discussion Rare systemic toxicity: Systemic botulism after cosmetic or therapeutic injection is exceptionally uncommon. Early clinical recognition and electrodiagnostic confirmation are essential for initiating timely antitoxin therapy. Biphasic anaphylaxis to BAT: Equine-derived BAT is the standard of care, yet biphasic reactions such as recurrence after apparent resolution are rarely reported. Extended monitoring and readiness for repeat epinephrine dosing are critical. Dual airway compromise: Airway obstruction resulted from both neuroparalytic weakness and anaphylaxis-induced laryngeal edema, necessitating early elective intubation and multidisciplinary critical care. Clinical implications: This appears to be the first reported case of iatrogenic systemic botulism complicated by biphasic anaphylaxis and airway edema. It underscores the need for rapid diagnosis, prompt BAT administration, vigilance for delayed hypersensitivity, and proactive airway management as botulinum toxin use expands.