Correct answer: A.
Rationale
This patient has scromboid poisoning, which occurs when histidine is converted to histamine by bacterial enzymes in improperly refrigerated fish. Most cases in the United States are reported in Hawaii, Florida, and California and involve consumption of affected tuna, mackerel, mahi-mahi, sardines, herring, and other fish. Onset of symptoms occurs about 1 hour after eating the suspect fish; the patient may experience hot flashes, facial flushing, hives, upper body rash, perioral paresthesias or edema, palpitations, lightheadedness, nausea, vomiting, and abdominal pain. Symptoms typically resolve within 1 day, though some patients may experience a longer course. Supportive care and either oral or intravenous administration of antihistamines may be used to improve symptoms. Evaluation of airway patency is also important. Scromboid poisoning may be prevented by immediate refrigeration of fresh fish to below 40°C.
Although ACE inhibitor induced angioedema may cause facial swelling, the time course of the disease and associated risk factors favor scromboid poisoning. Ingestion of Bacillus cereus or Staphylococcus aureus would not be expected to cause flushing, tachycardia, and upper body rash. Ciguatera poisoning has a less immediate onset of symptoms, is associated with neurologic symptoms, and has a more protracted course. This patient is not likely to have an allergy to seafood.
Reference
Hungerford JM. Toxicon. 2010 Aug 15;56(2):231-43.
