In addition to avoiding each type of shellfish, be wary of products that often contain shellfish or that are prepared alongside shellfish:
• Supplements – Glucosamine, which is a supplement used to treat arthritis symptoms, is typically made from the shells of crustaceans. Most people are not allergic to the shell, but check with your doctor before you use this supplement or look for the vegetarian variety. Omega-3 supplements are often made from seafood so be sure to read the label.
• Sauces – Avoid Worcestershire sauce, some salad dressings, and other sauces containing shellfish.
• Imitation shellfish – Although this is not real shellfish, imitation shellfish often contains extracts from shellfish for flavoring.
• Asian foods – Many Asian foods including Chinese, Thai, Japanese, Vietnamese, and Malaysian contain shellfish or use fish sauces. Be careful of these types of restaurants where even a dish without shellfish may not be safe. Cross-contamination can occur if your dish is prepared in the same area, using the same utensils, or stored in the same refrigerator with shellfish, or if your plate touches a plate containing shellfish on the way to your table.
Read the labels
The only way to avoid contact with shellfish is to read the labels on all products that might contain shellfish. Because shellfish is one of the top eight food allergens in the United States, the Food and Drug Administration requires food manufacturers to clearly label all products containing shellfish. You need to be wary of products that are made by the same company as products containing shellfish. Cross-contamination can take place if foods that do not contain shellfish are prepared in the same facility, or using the same equipment, or are packaged on the same line as foods containing shellfish.