Scombrotoxic fish poisoning

Synonyms: Scombroid or histamine fish poisoning

Overview
Scombrotoxic fish poisoning, also known as scombroid toxicity or scombrotoxic poisoning is a form of food poisoning. It is caused by histamine and histamine-like products of bacterial breakdown of seafood, inhibiting its metabolism. The exact aetiology is complicated as histamine is not generally absorbed via the gut and administration of oral histamine does not replicate the symptoms. Foods notably associated with it are:
 * Tuna
 * Mackeral
 * Bonito

Epidemiology and Demographics
Eating spoiled fish that have high levels of these histamines can cause in human disease.

Risk Factors
Symptoms may be more severe in patients taking certain medications that slow the breakdown of histamine by their liver, such as isoniazide and doxycycline.

Pathophysiology & Etiology
Scombrotoxic fish poisoning is caused by bacterial spoilage of certain finfish such as tuna, mackerel, bonito, and, rarely, other fish. As bacteria break down fish proteins, byproducts such as histamine and other substances that block histamine breakdown build up in fish.

History and Symptoms
Symptoms begin within 2 minutes to 2 hours after eating the fish.

The most common symptoms are:


 * rash
 * diarrhea
 * flushing
 * sweating
 * headache
 * vomiting

Burning or swelling of the mouth, abdominal pain, or a metallic taste may also occur. The majority of patients have mild symptoms that resolve within a few hours.

Treatment
Treatment is generally unnecessary, but antihistamines or epinephrine may be needed in certain instances.

Acknowledgements
The content on this page was first contributed by: C. Michael Gibson, M.S., M.D.