Scombroid is due to the ingestion of fish containing high levels of histamine due to spoilage after they are caught. Clinically it is similar to an acute hypersensitivity reaction. The fish most commonly implicated are tuna, kingfish, wahoo and mackerel from the Scombridae family.

Scombroid is similar to an acute hypersensitivity reaction, but because it results from only histamine it is not identical. The onset is over hours and it usually resolved after 6 hours.
The clinical effects are:
  1. Skin manifestations: diffuse erythema, flushing, itchiness and urticaria
  2. Gastrointestinal effects: nausea, vomiting, abdominal pain and diarrhoea.
  3. Cardiovascualr effects: hypotension
  4. Respiratory involvement: wheeze and bronchospasm.

Treatment is with H1 and H2-receptor antagonists and intravenous fluids.