Summary about Disease
Scombroid poisoning, also known as histamine poisoning, is a foodborne illness that results from eating spoiled fish. Certain fish species, when not properly refrigerated, can develop high levels of histamine due to bacterial growth. This histamine, when ingested, causes an allergic-like reaction.
Symptoms
Symptoms typically develop rapidly, within minutes to hours after eating the contaminated fish. Common symptoms include:
Skin flushing (especially on the face and upper body)
Sweating
Headache
Nausea
Vomiting
Diarrhea
Abdominal cramps
Burning sensation in the mouth
Hives or rash
Itching
Dizziness
Rapid or forceful heartbeat
Causes
Scombroid poisoning is caused by eating fish that contain high levels of histamine. This occurs when certain fish species, typically dark-meat fish, are not properly refrigerated. The bacteria that grow on the fish produce an enzyme that converts histidine (an amino acid) in the fish to histamine. Fish commonly associated with scombroid poisoning include:
Tuna
Mackerel
Mahi-mahi
Bonito
Anchovy
Herring
Marlin
Medicine Used
Treatment is primarily focused on alleviating symptoms. Medications used may include:
Antihistamines: To block the effects of histamine. Diphenhydramine (Benadryl) and cimetidine (Tagamet) are commonly used.
H2 Blockers: Such as Cimetidine.
Epinephrine: In severe cases with difficulty breathing or low blood pressure, epinephrine (an adrenaline shot) may be necessary.
Bronchodilators: If bronchospasm (narrowing of the airways) occurs.
IV Fluids: For dehydration resulting from vomiting or diarrhea.
Is Communicable
Scombroid poisoning is not communicable. It is not contagious and cannot be spread from person to person. It is solely caused by consuming contaminated fish.
Precautions
The best way to prevent scombroid poisoning is to:
Ensure fish is properly refrigerated or frozen: Fish should be kept at or below 40°F (4°C).
Purchase fish from reputable sources: Ensure the fish has been handled and stored correctly.
Cook fish thoroughly: While cooking will kill the bacteria, it does not destroy the histamine that has already formed.
Avoid fish that smells or tastes unusual: A peppery or metallic taste can be a sign of histamine.
Be cautious when eating fish that has been improperly stored: Even if it looks and smells normal, histamine levels may be high.
How long does an outbreak last?
Scombroid poisoning is not typically considered an "outbreak" in the traditional sense. It's usually a case-by-case occurrence affecting individuals or small groups who have eaten the same contaminated fish. Symptoms usually resolve within a few hours to a day with or without treatment.
How is it diagnosed?
Diagnosis is typically based on:
Clinical History: A person developing symptoms consistent with scombroid poisoning shortly after eating fish.
Symptoms: Characteristic symptoms such as flushing, headache, nausea, vomiting, and rash.
Response to Treatment: Improvement of symptoms after antihistamine administration supports the diagnosis.
Fish Testing: If available, testing the suspect fish for histamine levels can confirm the diagnosis. However, this is often not practical in most cases.
Timeline of Symptoms
Within minutes to a few hours after eating contaminated fish: Onset of symptoms.
Initial symptoms: Flushing, sweating, headache, nausea, burning sensation in the mouth.
Followed by: Vomiting, diarrhea, abdominal cramps, hives, itching, dizziness, rapid heartbeat.
Resolution: Symptoms usually resolve within a few hours to 1-2 days.
Important Considerations
Scombroid poisoning can mimic an allergic reaction to fish, but it is not a true allergy.
Even small amounts of histamine-containing fish can cause symptoms in susceptible individuals.
Individuals who have previously experienced scombroid poisoning may be more sensitive to histamine in the future.
Cooking the fish does not eliminate the histamine.
If you suspect scombroid poisoning, seek medical attention, especially if symptoms are severe or if you have underlying health conditions.