• Caused by eating fish which have been improperly stored/refrigerated
    • Bacteria grow and convert histidine in fish via histidine decarboxylase to histamine and histamine-like substances responsible for symptoms[1]
    • Patient may complain that the fish tasted like pepper, metallic, or bitter
  • Frequently misdiagnosed as seafood allergy
  • Most common incidence in US is state of Hawaii, followed by Florida [2]


Ingestion of:

  • Fish
    • Tuna
    • Bluefish
    • Mahi-mahi
    • Herring
    • Mackerel
    • Skip-jack
    • Sardine
    • Bonito
  • Swiss cheese (contaminated)

Clinical Features

Urticarial rash

Differential Diagnosis

  • Ciguatera - similar clinical presentation, different fish

Acute allergic reaction

Erythematous rash


  • Generally clinical diagnosis
  • Consider if symptoms present in multiple patients who ate same fish



  • Typically see a prompt response to treatment with antihistamines
  • Generally may be discharged

See Also


  1. Craig SA, Zich DK: Gastroenteritis, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 92:p 1211-1222
  2. Nguyen T, Akhtar S. Gastroenteritis. In: Walls RM, Hockberger RS, Gausche-Hill M, et al., eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier Saunders; 2018:(Ch) 84:1129–1149.