Seafood and shellfish allergies are quite common and often thought to be intertwined, though this is not always the case. Shrimp and oysters are both shellfish, but shrimp are crustaceans and oysters are mollusks. Having an allergy to shrimp does not automatically mean you also have an allergy to oysters. Shellfish allergies affect about 2.3 percent of the population. The results of a 2004 telephone survey published in the "Journal of Allergy and Clinical Immunology" showed that 38 percent of the respondents reported crustacean allergies and 49 percent reported being allergic to mollusks. Only 14 percent were allergic to both. Understanding which kind of shellfish will cause an allergic reaction allows you to avoid those that are a danger to you without sacrificing those that are safe.
There are over 300 different kinds of shrimp, which come in all colors ranging from dull brown to luminescent. Shrimp are an excellent source of heart-healthy omega-3 fatty acids, as well as offering vitamins B-12 and D, copper, iron, magnesium, phosphorus and zinc. Shrimp allergies often develop later in life, and once they develop they do not go away. While allergies to crustaceans like shrimp are the most common and do not mean you are also allergic to mollusks like oysters, it's best to get tested for a mollusk allergy to be safe.
Oysters are found throughout the world's oceans, living in colonies called beds or reefs that are located in shallow waters. The oysters you eat can produce pearls, though they are not true pearl oysters, which are a different species. Oysters can be eaten raw or cooked, though their rich and delicate salty flavor is often not enough reward for tolerating their definitely slimy texture, which novelist and comedian Carrie Fisher once compared to "elephant boogers." Oyster allergies present with the same symptoms as shrimp or other food allergies.
Food allergies, according to the University of Maryland Medical Center, are caused when someone who has a genetic sensitivity to a specific allergen comes in contact with a food containing that allergen. True food allergies, rather then sensitivities that trigger mild reactions involving the skin and the intestines, manifest symptoms within two hours of coming in contact with the food. Symptoms include a metallic taste in your mouth, runny nose, itching, eczema or hives, dizziness, difficulty breathing or swallowing and stomach problems like nausea, vomiting and diarrhea. Anaphylactic shock is an extreme reaction that requires medical attention, so get help if you experience swelling of your throat, trouble breathing, an elevated pulse rate or a bluish tint to your nails and skin.
Seafood restaurants, even those that are the most diligent about food hygiene, can have cross-contamination in their kitchens. If you are allergic to shrimp and ordering anything – even a non-seafood dish – in a seafood restaurant, mention your allergy to the staff. They will ensure your meal does not come into contact with shrimp.
- Glycemic Index: Shrimp Nutrition Facts
- National Geographic: Oyster (Ostreidae)
- University of Maryland Medical Center; Food Allergy; David Zieve, MD, MHA, and David R. Eltz; March 2010
- American College of Allergy, Asthma and Immunology: Shellfish Allergy
- "Journal of Allergy and Clinical Immunology"; Prevalence of Seafood Allergy in the United States . . . ; S.H. Sicherer et al.; July 2004
- Global Gourmet; Little Known Facts About Oysters; Ilene Polansky