Shellfish allergy is the most common food allergy among American adults. A 2019 national survey led by Ruchi Gupta at Northwestern estimated that about 2.9% of US adults have it, more than milk or peanut. It is also an allergy that often shows up later in life. According to FARE, roughly 60% of people with shellfish allergy had their first reaction as adults.
Most people with this allergy know to skip the shrimp cocktail. The harder cases are dishes where shellfish has been ground, fermented, and stirred into a sauce, and shrimp paste is the best example.
What Is Shrimp Paste, Exactly?
Shrimp paste is made from tiny shrimp or krill that are salted, fermented, and then dried or ground into a thick paste or block. It has a strong, savory smell that mellows once it is cooked into a dish. Cooks use it the way an Italian kitchen might use anchovies, as a background layer of depth.
It goes by many names depending on the region: kapi in Thailand, belacan in Malaysia, terasi in Indonesia, and bagoong alamang in the Philippines. Korean cooking uses a related ingredient, salted fermented shrimp called saeujeot.
Where Shrimp Paste Hides
- Thai curry pastes. Many traditional red, green, and Panang curry pastes include shrimp paste as part of the base. FDA recall records include curry sauces pulled for undeclared shrimp.
- Kimchi. Traditional recipes often use salted shrimp or other seafood, and kimchi products have been recalled for undeclared shrimp.
- Sambal and chili pastes. Some sambals and dipping sauces such as Thai nam prik are built on shrimp paste.
- Fried rice and stir fries. Dried shrimp and shrimp paste show up in many Southeast Asian and Chinese dishes, including XO sauce.
- Stocks and soup bases. Seafood stocks, bouillon, and hot pot bases may contain shrimp, crab, or krill.
- "Seafood flavoring." FARE lists this as a possible shellfish source.
Why It's So Easy to Miss
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The label covers half the family. US law treats crustacean shellfish (shrimp, crab, lobster, crayfish) as a major allergen and requires the label to name the species. Under FDA's current allergen labeling guidance, mollusks such as clams, oysters, mussels, scallops, squid, and octopus fall outside that rule. The EU, by comparison, requires both crustaceans and molluscs to be declared. If your allergist has told you to avoid mollusks too, a US "Contains" statement will only help with half of that list.
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The two groups can overlap. The main shellfish allergen is a muscle protein called tropomyosin, and it is similar across many species. Cross-reactivity within crustaceans is high. Between crustaceans and mollusks the estimates vary widely, and much of the data comes from self-report. Your allergist is the right person to sort out which groups you need to avoid.
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It disappears into the dish. Once a curry has simmered, shrimp paste is part of the flavor, with no visible pieces of shrimp to spot.
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Kitchens share equipment. Shared fryers, woks, and grills are common in seafood restaurants. FARE also notes that steam from cooking shellfish can carry the protein, which matters for people who react strongly.
Two Myths Worth Clearing Up
Iodine. Many people with shellfish allergy have been told to worry about iodine or the iodinated contrast dye used in CT scans. The AAAAI traces this idea to an untested survey from the 1970s. Iodine is an essential element that every body needs, and the allergy is to tropomyosin. A 2025 consensus from the American College of Radiology and the AAAAI confirmed that shellfish allergy is no special reason to avoid contrast. Do tell your care team about any past reactions to contrast itself.
Glucosamine. This joint supplement is often made from shellfish shells. In small oral challenge studies, shrimp-allergic people tolerated it. The studies were small, though, and some clinicians still advise caution after a severe reaction. Shellfish-free versions exist, and your allergist can help you decide.
How to Protect Yourself
- Ask about shrimp paste by name at Thai, Malaysian, Indonesian, Filipino, Vietnamese, and Korean restaurants. A server who says a curry has "no shrimp" may be thinking of the visible ingredients.
- Know which shellfish group you react to. Ask your allergist whether you need to avoid mollusks, and if so, read ingredient lists closely, since the "Contains" line will leave them out.
- Check jarred curry pastes, kimchi, and sauces every time. Recipes vary by brand and change over time.
- Carry your epinephrine. Adult-onset food allergies can be severe.
- Use ForkSure to get a quick read on a dish before you order or eat. ForkSure flags crustacean shellfish as one of the Big 9.
The Bottom Line
Shrimp paste carries a lot of flavor in very little volume, which is why it ends up in so many sauces and pastes where nobody sees it. Add a labeling rule that covers crustaceans and leaves out mollusks, and it is easy to see how people with shellfish allergy get caught off guard. Asking about specific ingredients by name, and knowing your own allergy in detail, closes most of that gap.
Stay safe, and when you need help, scan it with ForkSure.