A little ingredient knowledge.Hover or tap to reveal the crab
START WITH THE SOURCE
Understanding shellfish allergy.
Shellfish covers crustaceans and molluscs. Crustaceans include shrimp and crab; molluscs include oysters, squid and abalone. Squid belongs here even without a visible shell.
A small amount of paste or stock can flavour an entire dish. Ask about the cooking base as well as obvious seafood pieces.
Use these ingredient and preparation checks alongside your personal allergy plan. Knowing the name is the first step; the complete recipe and handling matter too. If your avoidance needs are unclear, ask your allergy team before changing what you eat.
Recognise shrimp paste, dried shrimp and oyster sauce alongside whole shellfish. The source matters even when it has been ground or dissolved. These are selected examples, not an exhaustive list. Follow the ingredient into powders, mixtures and finishing additions.
Small additions can be dispersed throughout a sauce or broth. Check the original stock and seasoning even when the finished dish is described as meat or vegetables.
Check broths, curry pastes and mixed seafood preparations. Removing the prawns does not remove their cooking juices or ingredients already mixed into a sauce.
Read the full ingredients list each time, including the ingredients inside a mix or sauce. Keep the packet available if staff need to check it. A product name or front-of-pack claim cannot answer every ingredient question.
Use the labelling guidance for the country where the food is sold. The foods covered, wording and presentation of allergen information can differ. Do not assume a familiar brand has the same recipe everywhere.
For unpackaged food, ask for ingredient information from the person preparing it. If a name or translation is unclear, keep the original wording available rather than guessing from a partial translation.
Use a checked stock or seasoning made without the shellfish you avoid. Fish sauce is a different ingredient, but should not be assumed suitable without checking its formulation and your allergies. Check the replacement as carefully as the original. If you regularly replace a major food group, discuss nutritional needs with a dietitian.
In place of
Options to consider
What to check
Shellfish stock
Options to considerVegetable stock
What to checkCheck the complete blend and the ladle or pot used.
Shrimp paste or oyster sauce
Options to considerA recipe using mushroom or vegetable seasoning
What to checkConfirm the replacement has no shellfish ingredients; formulations differ.
Shellfish as the main ingredient
Options to considerA tolerated option such as tofu, beans or chicken
What to checkFish is not an automatic substitute. Match choices to your individual allergy plan.
03 / FOLLOW THE PREPARATION
Explain the allergy, then ask about the kitchen.
Ask about shared boiling water, fryers and serving tools. Your allergy plan should identify which shellfish groups or species need avoidance; the broad menu word “seafood” is not precise enough.
Ask staff to check the recipe and any bought-in ingredients with the kitchen. Include the sauce, garnish and finishing step in the conversation, and explain which ingredients you need to avoid.
Get a clear answer about both ingredients and preparation before ordering. If the kitchen cannot confirm them, choose another option. A translated card can support this conversation when you do not share a language.
Shellfish includes crustaceans, such as prawns and crab, and molluscs, such as mussels and squid. The name does not mean every animal has a visible shell. Your allergy plan should identify the groups or species you avoid.
Finned fish is a separate group. Allergy to shellfish does not by itself establish fish allergy or fish tolerance. Mixed seafood stock, shared fryers and serving tools still need checking.
Shellfish allergy concerns proteins, not iodine. Tell healthcare professionals about your actual previous reactions rather than labelling the allergy as iodine allergy. They can assess any medication or contrast concerns separately.
Shellfish ingredients can be dispersed through cooking liquid. Ask for a preparation made without the shellfish you avoid, including stock, pastes and extracts. Taking pieces out does not recreate a meal prepared without them.
Cooking does not reliably destroy seafood allergens. Discuss any exposure to cooking steam with your specialist too. A grilled, boiled or fried version should not be assumed suitable because its texture has changed.
