Background. Scombrotoxinism is an acute toxin-induced illness caused primarily by bacterial synthesis of histamine in decomposed fish. Case Report. Immediately after taking 2-3 bites of cooked salmon, a clerical worker developed oral burning, urticaria, and asthma. In the emergency department, she was diagnosed with "allergies"; scombrotoxinism was never considered. She then developed wide-ranging symptoms (e.g., chronic fatigue, asthma, anxiety, multiple chemical sensitivity, and paresthesiae) and saw many specialists (in pulmonology, otorhinolaryngology, allergy, toxicology, neurology, psychology, and immunology). During the next 500+ days, she had extensive testing (allergy screens, brain MRI, electroencephalogram, electromyogram, nerve conduction velocity, heavy metal screen, and blood chemistry) with essentially normal results. She filed a workers' compensation claim since this injury occurred following a business meal. She was evaluated by a Qualified Medical Evaluator (GL) on day 504, who diagnosed scombrotoxinism. Comment. Scombrotoxinism should be considered in all patients presenting to the emergency department with "oral burning" or allergy symptoms following "fish consumption." Initial attention to such history would have led to a correct diagnosis and averted this patient's extended illness. Specialist referrals and tests should be ordered only if clinically indicated and not for diagnostic fishing expedition. Meticulous history is crucial in resolving clinical dilemmas.