A person allergic to shellfish may notice a range of symptoms after eating or being exposed to the shellfish or type of seafood she is allergic to. The severity of symptoms will depend on how bad the allergic reaction is. Typical symptoms include itching, breaking out in a rash or hives, a flushed or red face, and swelling of the face or tongue. Trouble breathing, vomiting, diarrhea, or a general feeling of being ill are also possible reactions. In some cases, the allergic reaction is life threatening and immediate hospitalization is required.
Seafood falls into three categories: fish, crustaceans, and shellfish. If a person is allergic to shellfish, that doesn't necessarily mean she is allergic to foods that fall into the fish or crustacean category. She should not experiment to find out, however. Instead, it's important for her to make an appointment with her regular doctor who can refer her on to an allergist. The allergist will use skin and blood tests to confirm a shellfish allergy and check for other related allergies.
Shellfish allergies can develop at any age. Those who have family members who are allergic to shellfish are more likely to develop the allergy. It also develops more often in adults than it does in children.
While there is currently no treatment for this food allergy certain precautions can help the afflicted person avoid an allergic reaction. Avoiding shellfish is key, but it's also important to avoid touching the shellfish or seafood that causes the reaction and to stay away from fumes where people are cooking shellfish or seafood. A doctor or allergist may give those with a severe allergy an adrenaline injection pen. If a severe allergic reaction occurs and the person has trouble breathing, she should inject the adrenaline and go to the emergency room.
Some people may believe that an allergy to shellfish means the person is also allergic to iodine. There is no direct connection between the two, however. While a person could certainly be allergic to both iodine and shellfish, being allergic to one does not mean that person will be allergic to the other. Iodine allergies are rare, but if a person is worried she can mention it to her doctor before receiving any treatment involving iodine.
An easy way for those allergic to shellfish to ensure a food does not contain any shellfish is to check the ingredient label. The packaging should have a list that says "May Contain" or "May Contain Traces Of" and list certain foods. If shellfish or another seafood that causes an allergic reaction is listed, avoid the food. When in doubt, the questionable food should not be eaten.