Shellfish Allergy Screen

Testing for Allergies:

Clam, Crab, Crawfish/Crayfish, Lobster, Octopus, Prawns/Shrimp, Scallop, Squid




What is a shellfish allergy?

It’s your body mistakenly seeing shellfish as a threat, and reacting to it.

What are the symptoms?

A range of symptoms ranging from vomiting, wheezing and coughing to swelling of lips and tongue, hives and, in worst cases, anaphylaxis.

Which shellfish?

Crustaceans (lobster, crab, shrimp prawns) are the main triggers for allergy, but you may also be allergic to squid, octopus, scallop and more.

How do I know if I have it?

A simple blood test is all you need. Book yours now.

Did You Know?

Shellfish is the most dangerous food allergen, responsible for more emergency hospitalisations than any other food type.

What is a shellfish allergy?

A shellfish allergy, like all food allergies, is triggered when your body’s immune system mistakenly treats certain foods (or rather, the proteins in them) as a threat. In response to that ‘threat’ your body releases chemicals which result in a wide range of symptoms, some of which can be life threatening.

Any allergy will usually be triggered by eating the shellfish. But it may also be triggered by touching it or simply smelling it or breathing vapour from cooking it.

Having a shellfish allergy does not automatically mean that you will be allergic to all fish. It is common to be allergic to fish but not shellfish and vice versa.

Shellfish allergies are most commonly triggered by crustaceans (crab, shrimp, lobster, prawns), although they can also include molluscs and other sea creatures including scallop, squid and octopus.

What are the symptoms of shellfish allergy?

A shellfish allergy can affect many areas of the body, often at the same time. Symptoms may include:

  • Wheezing and shortness of breath
  • Persistent coughing
  • Vomiting
  • A raised, red, itchy rash anywhere on the body (hives)
  • Swelling around the face, particularly the eyes, lips, tongue and roof of the mouth
  • Dizziness

In the most severe cases, a shellfish allergy can trigger anaphylaxis. This combination of breathing difficulties and feeling faint is commonly called anaphylactic shock and it can be fatal if left untreated. If you suspect anaphylaxis, dial 999.


The simplest ‘treatment’ is to avoid shellfish. Take particular care when ordering seafood in restaurants, as staff may not always know every ingredient used in the dish. Foods you buy in shops and stores should be clearly labelled as containing shellfish.

If you are at risk of a serious allergic reaction, talk to your GP about carrying an adrenaline auto-injector, which can help reduce the severity of an anaphylactic reaction.

How do I get tested?

Better2Know’s shellfish allergy testing covers a wide range of shellfish and molluscs including:

  • Clam
  • Crab
  • Crawfish/Crayfish
  • Lobster
  • Octopus
  • Prawns/Shrimp
  • Scallop
  • Squid

The simple blood test results in a positive or negative result. Whilst a positive result will not confirm the severity of any allergic reaction, a negative reaction will confirm you are safe to eat that particular seafood type.

To book your test contact Better2Know by calling the number displayed above on this page and speak to a member of our team.