Scombroid fish poisoning, also called histamine fish poisoning, is an allergic-type reaction caused by eating fish contaminated with high levels of histamine.
High levels of histamine in fish occur when certain kinds of fish are not properly refrigerated, which causes an increase in bacteria in the fish, resulting in a breakdown of the flesh of the fish and the production of high amounts of histamine.
Histamines are heat-resistant, which means even if fish is properly canned or cooked, illness may still occur. Freezing, cooking, smoking, curing, or canning does not destroy the toxins.
Some contaminated fish will look, smell, and taste normal, but histamine-contaminated fish often has a bad smell, a metallic, sharp, or peppery taste, and a “honey-combed” appearance.
Common sources of scombroid fish poisoning include:
- Fish in the Scombridae family (tuna, mackerel, skipjack, amberjack, and bonito)
- Mahi mahi
- Bluefish
- Dolphin
- Marlin
- Escolar
What Are Symptoms of Scombroid Fish Poisoning?
Symptoms of scombroid fish poisoning begin within minutes to several hours after consuming contaminated fish and often resemble an allergic reaction.
Symptoms of scombroid fish poisoning include:
- Tingling and burning sensations around the mouth
- Swelling of the mouth
- Difficulty swallowing
- Facial redness or flushing
- Reddening or flushing of the neck, arms, and upper part of the body
- Sweating
- Nausea
- Vomiting
- Stomach pain
- Diarrhea
- Headache
- Heart palpitations
- Dizziness
- Rash
How Is Scombroid Fish Poisoning Diagnosed?
Scombroid fish poisoning is usually diagnosed based on symptoms combined with consumption of fish right before symptoms appeared.
In some cases, laboratory testing may be done on uneaten fish to confirm a diagnosis. Try to keep portions of the suspect fish. Carefully handle the fish, packaged and frozen, to prevent deterioration.
What Is the Treatment for Scombroid Fish Poisoning?
Symptoms of scombroid fish poisoning are mild and resolve within a few hours. Sometimes, symptoms can last for several days.
Most of the time, treatment is not needed for scombroid fish poisoning.
In severe cases or in people who have underlying medical conditions, antihistamines or epinephrine may be indicated.
How Do You Prevent Scombroid Fish Poisoning?
Scombroid fish poisoning may be prevented in some cases:
- Only purchase fish from reputable vendors
- Fish should be refrigerated at 41oF (5oC) or colder from the time of capture to the time it is cooked and eaten
- Toxic histamine levels can be produced within less than 6 to 12 hours without ice or refrigeration
- Do not consume fish with a bad odor or “honey-combed” appearance
- Histamines are heat-resistant, so cooking contaminated fish does not make it safe to eat
From 
https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/ScombroidFish%20Poisoning.aspx
https://www.fda.gov/food/seafood-guidance-documents-regulatory-information/scombrotoxin-poisoning-and-decomposition