A 40-year-old high functioning woman developed severe anaphylaxis to rocuronium immediately following induction for laparoscopic appendectomy. Circulation and oxygenation were rapidly restored, the operation was abandoned and a 2-day intensive care unit stay, intubated with an adrenaline infusion for upper airway swelling, followed. The abdominal condition resolved with conservative management over a 5-day inpatient stay. Despite apparent full recovery from anaphylaxis, after discharge she had difficulty resuming baseline activities of daily living. Ongoing profound neurogenic fatigue prevented return to professional duties for over a year. Cognitive dysfunction following rapid resuscitation from anaphylaxis was unexpected. This case report examines relevant literature.