T61.14XD Scombroid fish poisoning, undetermined, subsequent encounter

Name of the Condition

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

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 of ingestion is not specified, and "subsequent encounter" refers to a visit for care after the acute phase of treatment.

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 fish consumption and characteristic symptoms. Laboratory tests are not typically required but may rule out other conditions. A detailed dietary history is essential to confirm exposure to potentially contaminated fish.

Treatment Options

Treatment is generally supportive, focusing on symptom relief. Antihistamines may be used for mild cases, while severe symptoms (e.g., respiratory distress) may require additional interventions. Rehydration and monitoring are common in clinical settings.

Prognosis and Follow-Up

Most cases resolve within 24 hours with appropriate care. Follow-up is recommended to ensure symptoms have fully resolved and to address any lingering effects. Complications are rare but may occur in severe or untreated cases.

Complications

Rare complications include respiratory distress, hypotension, or prolonged gastrointestinal symptoms. Severe reactions may require hospitalization for monitoring and supportive care.

Lifestyle & Prevention

Preventive measures include proper refrigeration of fish, avoiding consumption of fish with signs of spoilage, and ensuring food safety practices during handling and storage. Educating on high-risk fish species and storage guidelines can reduce incidence.

When to Seek Professional Help

Seek medical attention if symptoms are severe (e.g., difficulty breathing, significant hypotension) or if they persist beyond 24 hours. Immediate care is advised for respiratory or cardiovascular symptoms.

Tips for Medical Coders

Document the intent of ingestion as "undetermined" when not specified. For "subsequent encounter," confirm the patient is in a post-acute phase of treatment. Ensure clinical documentation supports the diagnosis and encounter type to align with coding guidelines.