Shellfish allergy is one of the most common food allergies running a close second to peanuts and other tree nuts. Most people who have a shellfish allergy will have a reaction of some kind to all types of shellfish, although one will probably give a more severe reaction over all the others. Shellfish include ocean fish that have shells such as lobster, crab and shrimp. And since the mainstay of the diet for octopus and squid is crab they also can cause problems for individuals who have shellfish allergies.
Other shellfish include abalone, clams, crawfish, oysters, scallops and mussels. Take care when ordering fried foods at a restaurant since many establishments will use the same oil to fry shrimp, chicken and french fries. Shellfish can also be used for flavoring in some processed foods so read labels carefully.
For the most part individuals who suffer from an allergic reaction to this shellfish will have mild symptoms such as nasal congestion or hives. In some instances the culprit will be gastrointestinal reaction that results in vomiting and subsequent swelling in the face. Other more severe symptoms will lead to anaphylaxis. In fact, shellfish and peanuts are the most common food allergies that lead to life-threatening anaphylaxis.
Many individuals who are allergic to shellfish develop their allergy in their 20s and 30s however it is possible for individuals into the mid-70s to develop an allergy to shellfish. If you believe that you’ve had an allergic reaction following a meal it is important to confirm this allergy with your physician and take steps to avoid reactions in the future.
Individuals who are highly sensitive to shellfish may react to the aerosolized protein when the fish is being cooked. It is wise to stay away from steam tables or stove tops when shellfish is being prepared. Even if you choose a meal without shellfish eating at a restaurant that serves seafood as their predominant menu items are considered high risk because of the possibility of cross contamination.
The symptoms of shellfish allergy can include the skin problems such as hives or eczema, swelling of the lips, face and tongue, wheezing or trouble breathing, abdominal pain accompanied by diarrhea, nausea or vomiting, dizziness or lightheadedness and a tingling in the mouth.
Although an anaphylactic reaction is rare it will be life-threatening and will interfere with breathing. Anaphylaxis is a medical emergency that requires immediate treatment. Symptoms can include airway construction which makes it difficult to breathe, a severe drop in blood pressure which can result in shock were losing consciousness, rapid pulse and lightheadedness.
A shellfish allergy shares similar symptoms with a reaction to food poisoning when the food has developed toxins or bacteria and prepared incorrectly. However, unlike food poisoning an allergy does affect the immune system and happens each time you eat a particular type of food.
Individuals who have family members who have allergies to anything are added and increased risk of developing a shellfish allergy as they grow older. It is most commonly diagnosed in adults and most common in women. When a shellfish allergy is found in children it is more common in boys.
At some point an allergy to iodine and shellfish became linked together in public knowledge. There is actually no relationship between an iodine allergy and a variety of seafood allergies. However, it is also possible for an individual to be separately allergic to both protein molecules so it is best be treated and diagnosed by an allergist who can determine the best possible treatment modalities available in your specific situation.
MayoClinic: Shellfish Allergy
American College of Allergy Asthma and Immunology: Shellfish Allergy
Cleveland Clinic: Shellfish Allergies
Food Allergy Initiative: Shellfish Allergy
Journal of Allergy and Clinical Immunology: Prevalence of seafood allergy in the United States determined by a random telephone survey
KidsHealth.org: Shellfish Allergy