Scombroid Poisoning • LITFL • CCC Toxicology

OVERVIEW

Scombroid poisoning occurs after the ingestion of fish with high histamine levels due to improper processing or storage
One of the most common causes of morbidity associated with fish intake

CAUSE

First described in scombroid fish of the suborder Scombroidea (e.g., tuna and mackerel) but occurs in other dark-fleshed fish too (e.g., sardines and anchovies)
fish may be fresh, canned or smoked
improper refrigeration before processing
storage of the fish at room temperature after cooking.
Histamine is heat-stable and remains present after cooking, freezing, canning or smoking.
Outbreaks are most common in summer.

CLINICAL FEATURES

Histamine does not change the smell or appearance of the affected fish
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 diarrhea.
Severe complications rarely occur: bronchospasm, respiratory distress and vasodilatory shock
rash lasts 2–5 hours
other symptoms usually disappear within 3–36 hours

DIFFERENTIAL DIAGNOSIS

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.
Histamine produced by the decarboxylation of histidine in the muscle of the fish is primarily responsible for the condition. The decarboxylation process is induced by enzymes produced by primarily enteric gram-negative bacteria (e.g., Morganella morganii, Escherichia coli, Klebsiella species and Pseudomonas aeruginosa) found in the fish’s cutis and intestines.

INVESTIGATIONS

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

MANAGEMENT

Most instances of scombroid poisoning are self-limited

Specific therapy

rapid-acting antihistamines (usually H1-receptor antagonists) often used
Adrenaline and corticosteroids are generally not indicated

Supportive care and monitoring

Disposition

public health authorities should be notified to investigate the source and remove the product from distribution

References and Links

LITFL

Journals

Stratta P, Badino G. Scombroid poisoning. CMAJ. 2012 Apr 3;184(6):674. doi: 10.1503/cmaj.111031. PMC3314039.

Critical Care

Compendium

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Chris Nickson

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.

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