Scombroid food poisoning
|Scombroid food poisoning|
|Classification and external resources|
However, it is often missed because it resembles an allergic reaction. It is most commonly reported with mackerel, tuna, bluefish, mahi-mahi, bonito, sardines, anchovies, and related species of fish that were inadequately refrigerated or preserved after being caught. The syndrome derived its name because early descriptions of the illness noted an association with Scombroidea fish (e.g., large dark meat marine tuna, albacore, mackerel); however, the Centers for Disease Control and Prevention (CDC) have identified other, nonscombroid vectors, such as mahi-mahi and amberjack. Scombroid syndrome can result from inappropriate handling of fish during storage or processing. One of the toxic agents implicated in scombroid poisoning is histidine, which is broken down into histamine. Other chemicals have been found in decaying fish flesh, but their association with scombroid fish poisoning has not been clearly established.
Unlike many types of food poisoning, this form is not brought about by ingestion of a bacterium or virus. Histidine exists naturally in many types of fish, and at temperatures above 16°C (60°F) on air contact it is converted to the biogenic amine histamine via the enzyme histidine decarboxylase produced by enteric bacteria including Morganella morganii (this is one reason why fish should be stored at low temperatures). Histamine is not destroyed by normal cooking temperatures, so even properly cooked fish can be affected. Histamine is a mediator of allergic reactions, so the symptoms produced are those one would expect to see in severe allergic responses.
Symptoms consist of skin flushing, throbbing headache, oral burning, abdominal cramps, nausea, diarrhea, palpitations, a sense of unease, and, rarely, collapse or loss of vision. Symptoms usually occur within 10–30 minutes of ingesting the fish and generally are self-limited. Physical signs may include a diffuse blanching erythema, tachycardia, wheezing, and hypotension or hypertension. People with asthma are more vulnerable to respiratory problems such as wheezing or bronchospasms. Symptoms of poisoning can show within just minutes, and up to two hours, following consumption of a spoiled dish. Symptoms usually last for about 10 to 14 hours, and rarely exceed one to two days.
The first signs of poisoning suggest an allergic reaction with the following symptoms:
- facial flushing/sweating
- burning-peppery taste sensations in the mouth and throat
- cold-like symptoms
The above symptoms can advance to:
- facial rash
- torso or body rash: The rash associated with scombroid poisoning is a form of urticaria, but most commonly does not include wheals (patchy areas of skin-swelling also known as hives) that may be seen in true allergies.
- edema (this is generalized if it occurs at all)
- short-term diarrhea
- abdominal cramps
In the worst cases, the poisoning may cause:
- blurred vision
- respiratory stress
- swelling of the tongue
Treatment is in the form of supportive care such as fluids and oxygen. H1 and H2 receptor (histamine receptors) blocking medications can also be given with some success. Oral antihistamines are very effective, showing improvement within 10–15 minutes.
- Clark RF, Williams SR, Nordt SP, Manoguerra AS (1999). "A review of selected seafood poisonings". Undersea Hyperb Med 26 (3): 175–84. PMID 10485519. Retrieved 2008-08-12.
- "Poisoning - fish and shellfish". MedlinePlus - National Institutes of Health's Web site. Retrieved 6 September 2012.
- Guss DA (1998). "Scombroid fish poisoning: successful treatment with cimetidine". Undersea Hyperb Med 25 (2): 123–5. PMID 9670438. Retrieved 2008-08-12.
- Overview at Clemson University
- Seafood Network Information Center
- Center for Disease Control: Food Poisonings from Marine Toxins
- DermNet reactions/scombroid