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Understanding Shellfish Allergies In Babies

February 10, 2022 4 min read

Affecting around 2%, or 6.6 million, Americans, shellfish allergies are among the nine most common food allergies in adults and children in the United States.

There are two groups of shellfish. Crustaceans, like shrimp, lobster, and crab, and mollusks like scallops, oysters, clams and mussels. Crustaceans, especially shrimp, cause the greatest number of allergic reactions, while mollusks are generally more tolerable.

With shellfish allergies presenting as a significant health concern, SpoonfulONE is here to help educate parents on the facts and statistics surrounding this food allergy.

How Common Is A Shellfish Allergy In Babies?

Affected by both genetic and environmental factors, a food allergy occurs when your child's immune system decides that a certain food is a "danger" to their health. Their immune system starts sending out immunoglobulin E (or IgE) antibodies that react to the food and cause an allergic reaction.

Shellfish is an allergy that is most common in adults, however, around 0.6-1% of children still suffer from this allergy. Though .6% may not seem like a lot, if you consider that up to 4 million babies are born in the United States each year, this adds up. 

And every year, food allergy rates are increasing. The CDC reports that the prevalence of food allergies in children has increased by 50% between 1997 and 2011, with as many as 6 million children in the United States developing some form of food allergy. 

What Does A Shellfish Allergy Look Like

Like other food allergens, these reactions can range from mild, like sneezing or itching, to severe, like swelling or anaphylaxis that results in difficulty breathing and a sudden drop in blood pressure that sends the body into shock. 

Most food-related shellfish allergy symptoms occur within minutes of eating or being exposed to shellfish proteins, but allergic reactions can still occur within 2-4 hours of ingestion. Signs that your baby has developed a shellfish allergy may include:

  • Stomach distress including vomiting, cramps, indigestion, or diarrhea
  • Difficulty breathing, wheezing, or shortness of breath
  • Repetitive cough, hoarse voice, or tightness in the throat
  • Hives, red skin, or swelling around the face, mouth, or tongue
  • Confusion, dizziness, or loss of consciousness
  • Weak pulse
  • In rare cases, anaphylaxis

If your child has shown a reaction to shellfish, you should have your pediatrician test for a food allergy. Common testing methods include a skin prick test, IgE testing, and an oral food challenge. 

Long-Lasting Effects Of A Shellfish Allergy

According to the ACAAI, about 40% of children with a food allergy are allergic to more than one food. In fact, studies have shown that children with an allergy to one type of shellfish are more likely to have an allergic reaction to another type of shellfish, such as crab, shrimp or lobster. While considered likely, it does not always mean they will not be able to enjoy other types of shellfish.

Furthermore, allergies to shellfish tend to last a lifetime and reactions can even occur when not ingesting the food, such as if you are close to shellfish being cooked, or if your food came in contact with shellfish.

A shellfish allergy is different than an allergy to fish, and you can still have a shellfish allergy and be able to enjoy finned fish like tuna, salmon, and cod. However, it is important to be careful of cross contamination which commonly happens in restaurants, markets, or manufacturing facilities where both shellfish and finned fish are served. 

Lastly, studies have shown that children with a food allergy are two to four times as likely to develop other allergic conditions, such as asthma or eczema, which can have long-reaching impacts on your little one’s quality of life. 

How To Manage Shellfish Allergies

Fortunately, most types of shellfish are rarely hidden in foods, and are easily identifiable on ingredient labels. As one of the most common allergens, the Food Allergen Labeling and Consumer Protection Act of 2004 requires that crustacean shellfish must be listed in the ingredient label. However, it does not require that mollusks be labeled in plain language, making mollusk allergies a little more difficult to manage. 

If your child has developed an allergy to shellfish, read labels carefully and be sure to entirely avoid shellfish and shellfish products altogether. 

Crustaceans include:

  • Crab
  • Lobster
  • Crayfish
  • Shrimp
  • Prawns 

Mollusks include:

  • Clams
  • Scallops
  • Oysters
  • Mussels
  • Squid/Octopus
  • Snails

Shellfish products can also be found in fish stock or seafood flavoring. As shellfish is often stored together in restaurants or food markets, cross contamination can be an issue. This goes the same for fish and shellfish products. 

If you find that your child is showing shellfish allergy symptoms to a specific type of shellfish, such as shrimp, you should consult an allergist before eating any other kind of shellfish.

How to Avoid A Shellfish Allergy in Babies

We know that no parent wants to see their child suffer from food allergies, but unfortunately, there is no guarantee that they can be avoided. 

However, there is still hope. Groundbreaking clinical studies, like LEAP and EAT, have taught us that babies who were given potentially allergenic foods as a regular part of their diet were less likely to develop a food allergy. 

According to the AAP and the USDA’s latest guidelines, you can (and should!) start introducing allergenic foods like shellfish to your baby alongside other solids. In fact, experts now consider it safe for your child to start allergen introduction as early as four months, rather than later in life. 

At SpoonfulONE, we believe regular, consistent exposure to common allergens in the diet throughout early childhood is key to staying healthy.