Crab, along with other shellfish, is one of the seven foods that causes 90 percent of food allergies, notes AskDrSears.com. A numb tongue is an indication that you are sensitive to crab and should consult a physician for testing. Food allergies can vary in severity, even within one person, so you need to know for sure if you are allergic to avoid future, potentially more severe, reactions.
Crab Allergy
You could be allergic to just crab or to all shellfish, including shrimp, squid and lobster. Your immune system reacts to a protein in the crab and releases chemicals called histamines in an attempt to help protect you. These histamines cause varying symptoms, among them a swollen tongue. Other symptoms of an allergy include swelling of other parts of your face, wheezing, fainting, itching, vomiting and diarrhea. In serious cases, an allergy to crab can cause anaphylactic shock, which is characterized by a comprised respiratory system. This could lead to death. You are at a greater risk of developing this complication if you have asthma or react to a very small amount of crab.
Risk
If others in your family have an allergy to shellfish, or crab in particular, you are more likely to have a shellfish allergy, too. If your mother and father have food allergies, you have a 75 percent chance of having one yourself. If only one parent has an allergy, you have a 30 to 40 percent chance of having one, reports the University of Maryland Medical Center. If no one else in your family has a food allergy, you still have a 10 to 15 percent chance of developing one to crab or other foods. Some food allergies, such as those to eggs or milk, are often outgrown as you become an adult; shellfish is an allergy that tends to persist into adulthood. You can develop a food allergy at any time -- you are never too old.
Indication and Strategy
A tongue that swells within minutes of consuming crab is a strong indication that you have an allergy. Your doctor may conduct a skin-prick or blood test to confirm your allergy. If you are allergic, you should avoid crab – even small amounts. Having an allergy to crab increases the chances that you are allergic to other types of shellfish.
Treatment
If you do accidentally eat crab and experience a swollen tongue, your doctor may recommend that you take an over-the-counter antihistamine. Because you never know how severe your reaction may be, you should not rely on antihistamines to protect you against a crab allergy. Eliminating the food from your diet is the safest strategy.
