Allergies to seafood are among the most common food allergies suffered by adults and older children. Seafood is a powerful allergen and can induce a life-threatening reaction called anaphylaxis, according to the Asthma and Allergy Foundation of America. Someone can have an allergy to one particular type of seafood or many types. Allergies to seafood run in families, with women more likely to have a seafood allergy than men. Once developed, an allergy to seafood is not likely to go away and may worsen over time. Seafood includes fish and shellfish, such as shrimp, lobster, conch, abalone, halibut, salmon and trout.
Nasal Congestion
Symptoms of an allergic reaction to seafood typically occur within minutes up to a few hours after eating the seafood, according to the Cleveland Clinic. Some people experience symptoms of nasal congestion while having a mild allergic reaction to seafood.
Gastrointestinal Upset
A mild allergic reaction to seafood can produce some gastrointestinal discomfort. Some people may experience nausea and diarrhea, according to MayoClinic.com. A stronger allergic reaction can produce abdominal pain and vomiting, along with diarrhea. The gastrointestinal symptoms mimic those that occur with food poisoning--the difference being that symptoms from an allergic reaction will occur every time seafood is consumed.
Itching and Hives
Some people with a seafood allergy may develop itching or a case of hives, according to the Cleveland Clinic. The severity of the itching and hives depends on the strength of the reaction: the more severe the reaction, the more severe the symptoms are.
Wheezing and Difficulty Breathing
People who suffer from a severe allergic reaction begin to wheeze and experience tightness in the chest, which can lead to difficulty breathing. Allergic reactions involve the immune system, which identifies some of the proteins in seafood as harmful and triggers an antibody response against them, according to MayoClinic.com.
Swelling
Another symptom that may be experienced during an allergic reaction to seafood is swelling of the mouth, lips, tongue and throat. Swelling may also occur in other parts of the body, and there may be a tingling feeling in the mouth, according to MayoClinic.com.
Dizziness and Fainting
Because dizziness, light-headedness and fainting may occur, the Cleveland Clinic recommends wearing a medical alert bracelet and carrying a medical alert card at all times.
Anaphylaxis
Although rare, some people with seafood allergies develop a life-threatening allergic reaction called anaphylaxis, according to CNN Health. The symptoms of anaphylaxis occur swiftly and include severe swelling of the throat, which causes airway constriction; rapid pulse; development of shock; a severe drop in blood pressure; and possibly loss of consciousness. Anaphylaxis is a medical emergency that requires immediate medical attention and a 911 alert. People with seafood allergies should read the labels on all foods to check for any offending ingredients.
