Mollusc Allergies: Shellfish in disguise

Allergies come in all shapes and sizes. A mollusc allergy may be one of the few spoken about allergens, and can often get mixed up with shellfish allergies.

What is a Mollusc?

A mollusc is an invertebrate creature, most if not all molluscs have a soft body and the majority have some form of a calcareous shell. The most common types of molluscs are snails, slugs, mussels and octopuses. 

Their size can vary, and most molluscs prefer an aquatic or damp living environment.

What is a Molluscs allergy?

A mollusc allergy is a reaction to certain types of proteins found in molluscs. Your body encounters these proteins and it creates antibodies that attack the protein. This attack causes your body to form a reaction. The severity of the reaction can be related to the severity of your allergy. 

How do I know if I have a mollusc allergy?

You should always seek advice from your GP if you are concerned about suffering from any allergy. However, some signs you have a mollusc allergy can be seen after ingesting, or coming into contact with molluscs and having adverse or mild symptoms. Symptoms can involve anything from swelling of the tongue to rashes. 

More symptoms can include:

  • itching

  • Swelling of the lips, face, throat, or other parts of the body

  • Wheezing, congestion, or difficulty breathing.

  • Abdominal pain,

  • Dizziness, lightheadedness or fainting

What is the difference between a mollusc allergy and a shellfish allergy?

There are very few differences between a mollusc allergy and a shellfish allergy in regards to reactions. Some people may have allergic reactions to both types of creatures, or only one in particular. People may be severely allergic to molluscs, or only have a mild allergic reaction to them. 

Ultimately, as with any allergic reaction, it’s important to get treated for the symptoms straight away and ensure the foods you are eating do not contain the allergen or traces of the allergen. Visiting your GP should become a priority if you believe you may have any allergy or sensitivity to molluscs. 

How can I know what foods contain molluscs?

When looking at menus, or ingredient lists all allergens should be listed in bold. If you are unsure you can double-check with either the server or the manufacturer of the product you are looking to consume. The amount of avoidance of a particular allergen is a personal choice. If you have a mild sensitivity to molluscs you may be able to tolerate small traces of them in foods. If you are unsure, avoiding the allergen is always the safest practice.

For restaurants and hospitality industries it is important that your labelling systems are clear not only for your employees but also for your customers. Allergen Checker provides a 7 day free trial for our allergen labelling system. 

The information provided in this blog is purely informational. Please speak to your GP for further information on any concerns you have regarding allergies. Sources for information are: