Scombroid poisoning occurs after the ingestion of fish that have been stored or processed inadequately, leading to high histamine levels in the body. It is is one of the most common causes of morbidity associated with fish intake.
The term “scromboidism” derives from the Scombridae fish family, that makes up 51 species, including mackerel, tuna, and bonito.
The amino acid, histainde, is found in fish cutis and intestines. Histidine is decarboxylated to histamine by primarily enteric gram-negative bacteria (e.g., Morganella morganii, Escherichia coli, Klebsiella species and Pseudomonas aeruginosa). When fish are incorrectly stored, more histamine is produced as a result of bacterial overgrowth. Histamine does not change the smell or appearance of the affected fish and his heat-stable, remaining present after cooking, freezing, canning or smoking.
- The most common cause is consuming fish from the Scombridae family
- Non-scombroid species such as herring, sardines, anchovies, and mahi-mahi have been implicated in the syndrome and occasionally the ingestion of cheese such as Swiss, Cheddar and Gouda
- Fish may be fresh, canned or smoked
- Improper refrigeration of the fish before and after cooking
- Outbreaks are most common in summer
- Symptoms begin within 10 to 90 minutes after ingestion
- Flushing, rash, urticaria (generally widespread erythema, usually lacking wheals), palpitations, headache, dizziness, sweating, and burning of the mouth and throat
- Gastrointestinal symptoms can include abdominal cramps, nausea, vomiting and diarrhoea
- Severe complications rarely occur: bronchospasm, respiratory distress and vasodilatory shock
- Rash lasts 2–5 hours
- Other symptoms usually disappear within 3–36 hours
Example clinical case
A 38 year old male presents to ED with an erythematous and widespread rash 30 minutes after eating sushi at a restaurant. He is light-headed and has vomited once. Below are 2 photographs and 1 video of his rash.
- Scombroid poisoning is frequently misdiagnosed
- Allergic reactions typically affect one person who has a history of specific allergy
- With scombroid poisoning, more than one person, often with no history of allergies, may be affected.
- The diagnosis is generally clinical
- Can be confirmed by measurement of histamine in spoiled fish
- Diagnosis supported by plasma histamine level or histamine metabolites (e.g., n-methylhistamine) in patient’s urine
- Most instances of scombroid poisoning are self-limited
- Specific therapies can include rapid-acting antihistamines (usually H1-receptor antagonists)
- Adrenaline and corticosteroids are generally not indicated
- Supportive care and monitoring
- Public health authorities should be notified to investigate the source and remove the product from distribution
References and Links
- Stratta P, Badino G. Scombroid poisoning. CMAJ. 2012 Apr 3;184(6):674.
- Byard RW. Death by food. Forensic Sci Med Pathol. 2018 Sep;14(3):395-401.
- Eyer-Silva WA, Arteaga Hoyos VP, Nascimento L. Scombroid Fish Poisoning. Am J Trop Med Hyg. 2022 Mar 21;106(5):1300.
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.