Approach Considerations
Most cases of histamine fish poisoning are self-limited; duration is less than 6 hours. However, comorbid atopic conditions (ie, asthma) have been reported to extend course duration and severity. [19]
Bronchospasm is treated with oxygen and beta-adrenergic agents. Hypotension is treated with IV fluids and, rarely, pressors. Administration of epinephrine, because of the mistaken belief that the patient is experiencing an acute allergic reaction, will also result in rapid resolution of symptoms. [20]
Hospital admission is required only under exceptional circumstances. Criteria for admission are severe comorbidity or refractory toxicity that mandates respiratory or pressor support.
Most cases require no consultation for medical management. Consultation may be requested from the local health department to help confirm diagnosis. Contact the regional poison control center or a local medical toxicologist for additional information and patient care recommendations. Notify the local health department of any case of histamine fish poisoning, especially if the source was public, in order to help prevent additional cases.
Prehospital and Emergency Department Care
Prehospital care is primarily supportive. Emergency personnel may provide oxygen and monitor cardiac function as needed. Advanced life support personnel may use antihistamines and bronchodilators as appropriate.
In the emergency department (ED), if the patient has only minimal symptoms of histamine toxicity, reassurance and observation may be the only treatment necessary. If clinically necessary, obtain an ECG and institute intravenous access, oxygen, and cardiac monitoring. H1 and H2 blockers can provide symptom relief.
Consider use of activated charcoal only if the patient ate a large amount of fish, presents very early after the meal (within 1 hour), and can adequately protect his or her airway. Use of ipecac or gastric lavage is not recommended, as these can result in complications.
Bronchospasm is a rare manifestation of histamine toxicity. If it occurs, use standard treatment, as follows:
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Inhaled beta2-adrenergic agonists
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Inhaled ipratropium bromide (may be particularly useful for the treatment of histamine-induced bronchospasm)
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Epinephrine
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Corticosteroids
Extremely rare reported cases of myocardial dysfunction, ischemia, or infarction related to histamine fish poisoning exist [21] ; standard treatment for these complications should be used. One reported case documents successful treatment of a 36-year-old woman with severe myocardial dysfunction refractory to pressor support by using a biventricular assist device for 8 days. [22]
The vast majority of patients may be discharged from the ED with oral H1- and H2-blockers for the next 3-5 days. Headache often responds H2 blocker treatment. The patient may return to normal activity as tolerated.
Patients may express concern about future allergic reactions to fish and seafood. Reassure patients that their illness resulted from improper fish handling and storage, not from an allergic reaction.
Prevention
Proper refrigeration and transport prevents histamine fish poisoning. Fish should be chilled immediately after being caught; the goal is to achieve an internal temperature of 50°F (10°C) within 6 hours. The ambient storage temperature should be below 40°F (< 4.4°C) throughout the entire handling process. [14] Toxicity can result from the consumption of fresh fish that has been inadequately cooled and refrigerated, or of frozen fish that has been allowed to sit at room temperature for a prolonged time after thawing.
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Mackerel.
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An example of a typical histamine toxicity rash, in this case from tuna. Image courtesy of Amanda Oakley, MBChB, FRACP.
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An example of a typical histamine toxicity rash, in this case from tuna. Image courtesy of Amanda Oakley, MBChB, FRACP.
