T61.14 Scombroid fish poisoning, undetermined

Name of the Condition

• Common Name(s): Scombroid Fish Poisoning, Histamine Fish Poisoning
• Technical Terms: Scombroid Fish Poisoning, Undetermined

Summary

Scombroid fish poisoning is a foodborne illness caused by consuming fish with elevated levels of histamine. This condition typically results from improper handling or storage of certain fish species, leading to bacterial growth and histamine production. Symptoms usually appear within minutes to hours after ingestion and may mimic allergic reactions. The "undetermined" designation indicates the intent or circumstances of exposure are not specified.

Causes

The primary cause is consuming fish that has not been properly refrigerated or stored, allowing bacteria to convert histidine into histamine. Fish species prone to this include tuna, mackerel, mahi-mahi, and other dark-meat fish. Cooking or freezing does not reduce histamine levels, so contamination persists even after preparation.

Risk Factors

• Eating fish from unrefrigerated or poorly stored sources.
• Consumption of fish with high histidine content (e.g., tuna, mackerel).
• Inadequate food safety practices during handling or storage.
• Purchasing fish from unregulated or unverified suppliers.

Symptoms

• Gastrointestinal: Nausea, vomiting, diarrhea, abdominal cramps.
• Neurological: Headache, flushing, dizziness, palpitations.
• Dermatological: Urticaria (hives), itching, facial swelling.
• Respiratory: Wheezing or difficulty breathing (rare).

Diagnosis

Diagnosis is primarily clinical, based on a history of recent fish consumption and characteristic symptoms. Laboratory tests may confirm elevated histamine levels in leftover fish or patient samples, though this is not always necessary. Differentiation from allergic reactions or other foodborne illnesses may be required.

Treatment Options

Treatment focuses on symptom relief, including antihistamines for mild cases. Severe symptoms may require supportive care, such as intravenous fluids or medications for respiratory distress. Most cases resolve within 24 hours with appropriate management.

Prognosis and Follow-Up

Prognosis is generally good, with symptoms resolving spontaneously or with treatment. Follow-up is typically unnecessary unless complications arise or symptoms persist beyond 24 hours. Patients should avoid consuming improperly stored fish in the future.

Complications

Rare complications include severe respiratory distress, hypotension, or prolonged symptoms requiring hospitalization. These are more likely in individuals with pre-existing conditions or high histamine exposure.

Lifestyle & Prevention

• Ensure fish is refrigerated promptly after catch or purchase.
• Cook fish thoroughly, though this does not eliminate histamine.
• Avoid consuming fish with a peppery or spoiled taste.
• Practice proper food handling and storage to prevent bacterial growth.

When to Seek Professional Help

Seek medical attention if symptoms are severe (e.g., difficulty breathing, dizziness, or persistent vomiting) or if exposure to contaminated fish is suspected. Prompt evaluation can rule out other conditions and provide appropriate treatment.

Tips for Medical Coders

Use T61.14 for cases of scombroid fish poisoning where the intent or circumstances are undetermined. Document the clinical presentation, including symptom onset, fish consumption history, and any diagnostic findings. Ensure the code aligns with the provider's documentation of the exposure context.