Shellfish Allergy

Usually lifelong, allergies to shellfish cause an allergic reaction when you eat shellfish like marine animals with shells, such as shrimp, crab, and lobster, as well as octopus and squid. Shellfish allergy can occur only to certain kinds of shellfish, or you may have a multiple allergy to many shellfish foods.
Shellfish allergy can cause mild symptoms, such as hives, red and itchy skin or nasal congestion and more severe, even life-threatening symptoms such as anaphylaxis, which is an emergency situation, requiring immediate attention. For some people, even a tiny amount of shellfish can cause the most severe reactions.


Shellfish allergies (crustacean and mollusks) predominantly affect adults and are rare among infants and schoolchildren. In many continental countries, shellfish allergies are more predominant in adults, while in countries where shellfish is a basic dietary food source, seafood allergies are common among both adults and children. Approximately 60 percent of people with shellfish allergy experienced their first allergic reaction as adults. Shrimp, crab and lobster cause most shellfish allergies. Finned fish or scaly fish and shellfish (like mussels, oysters and shrimp, lobster) do not come from related families of foods, so being allergic to one group does not necessarily mean that you must avoid all seafood and fish products in general. To prevent a reaction, strict avoidance of shellfish and shellfish products is essential.

If you have a shellfish allergy, communicating your restrictions about which foods to avoid is the best step to treat your allergy.
Always read ingredient labels and ask restaurant employees to identify shellfish ingredients. Communication is the key for ensuring a safe, enjoyable allergen free meal. Use or “Food Allergy Translate App” or your “Personal Food Allergy Translate Cards” to gain better understanding!

Allergic reactions

There are two types of shellfish: crustacean (such as shrimp, crab and lobster) and mollusks (such as clams, mussels, oysters and scallops). Reactions to crustacean shellfish tend to be particularly more severe and more predominant. Interesting: Studies suggest that shellfish allergies tend to fall within groups. In fact, many people are only allergic to a single type of shellfish. For example, some people can eat oysters safely but they react to lobster. The Asthma and Allergy Foundation of America estimates that the majority of food allergy sufferers who have seafood allergies (scaly fish or shellfish) are adults.

Avoid foods

Many countries require that all packaged food products that contain fish products as an ingredient must list the word “Fish or Shellfish” on the label. However this is not the case in all countries. Many restaurants are especially not following such guidelines and no long-term solutions exist for informing guests with food allergies about the potential presence of the nine major allergens. Do not let that eating out becomes one of your top concerns.

As shellfish is one of the primary sources of dietary protein in many overseas countries (China, Thailand, Japan, etc), avoidance of such allergic proteins can often be frustrating and difficult. Allergies can be limited to a specific kind of shellfish or to all seafood in general. Whatever the case, you will want to make sure how to avoid these foods when dining abroad.

Avoid foods that contain shellfish or any of these ingredients:

  • Abalone, clam, cockle, conch, limpets, mussels, octopus, oysters, periwinkle, quahaugs, scallops, land and sea snails (escargot), squid (calamari), whelks
  • Antipasto
  • Barnacle
  • Caponata
  • Crab
  • Crawfish (crawdad, crayfish, ecrevisse)
  • Cuttlefish
  • Krill
  • Lobster (langouste, langoustine, Moreton bay bugs, scampi, tomalley)
  • Prawns
  • Shrimp (crevette, scampi)
  • Clams (cherrystone, geoduck, littleneck, pismo, quahog)
  • Cockle
  • Cuttlefish
  • Limpet (lapas, opihi)
  • Mussels
  • Lobster
  • Marinara sauce
  • Mollusks
  • Mussel
  • Octopus
  • Pizza Toppings
  • Prawn
  • Oysters
  • Periwinkle
  • Sea cucumber
  • Sea urchin
  • Scallops
  • Snails (escargot)
  • Squid (calamari)
  • Sushi
  • Whelk (Turban shell)
  • Special food supplements


Shellfish is found

Watch out for cross-contamination and hidden source of shellfish and shellfish derivatives.
If you have shellfish allergy, try to avoid seafood and fish restaurants or communicate your needs very clearly. Even if you order seafood-free item off of the menu, cross-contact may occur with huge possibility in a seafood restaurant.
Asian, Caribbean and Polynesian restaurants often serve dishes that use fish sauce as a flavoring. Exercise special attention and use our Food Allergy Translate App to clarify your food allergy message.

High risk countries

High risk countries to travel with shellfish allergy

  • Asian countries
  • Benelux
  • Caribbean
  • Croatia
  • Poland

With clear communication food allergies can be effectively managed!
According to experts and allergist the most effective and therefore best way to manage a food allergy is total avoidance. Novel solutions of communication seem to be a proven treatment for food allergies. Our Food Allergy Translate tools are contribution strategies to minimize your risk of accidents.

Eating out with food allergy!

Reduce your risk dramatically by using our Food Allergy Translate App or Personal Food Allergy Translate Cards to communicate your allergy alert in a foreign language.
Let the food service personnel know of your food allergy in advance. At least they should take extra care in preparing your meal!

Be prepared to communicate your needs in any restaurants. Let the restaurant/catering staff informed for avoiding the potential presence of the nine major allergens.

Asthma and Allergy Foundation of America 2005;
National Institutes of Health, NIAID Allergy Statistics;
National Report of the Expert Panel on Food Allergy Research, NIH-NIAID 2003;
American Academy of Allergy, Asthma and Immunology (ACAAI), Tree Nut Allergy;
Food Allergen Labeling and Consumer Protection Act of 2004;
Stanford Alliance for Food Allergy Research (SAFAR). California 2013;
Canadian Food Inspection Agency. 2009)