Shellfish Allergy: Symptoms, Awareness & Prevention for Canadians

A shellfish allergy is an immune response to proteins found in many marine foods such as shrimp, crab, lobster, clams, mussels, squid, and octopus. Some people react to only certain shellfish, while others react to many. Shellfish allergy is among the more common food allergies worldwide and can range from mild to more serious reactions.

First Aid & Workplace Relevance

Food allergies matter in Canadian workplaces, especially in food service, hospitality, childcare, healthcare, and recreation settings. Awareness supports safer menu planning, labelling, and first aid response, while reducing the risk of accidental exposures during travel, shared meals, or catered events.

Realistic Scenario

At a company picnic, an employee tried a seafood skewer without realizing it contained shrimp. Minutes later, they developed itching around the mouth and small hives on their neck. A trained first aid rescuer calmly checked for breathing difficulty, reassured the individual, and provided supportive monitoring while coworkers brought ingredient packaging to confirm the exposure. Symptoms remained mild, and the employee chose to go for medical assessment to review allergy history. The workplace later reviewed food labelling and event planning to improve safety.

Symptoms of Shellfish Allergy

Symptoms often begin within minutes to an hour after eating shellfish. They may range from mild to more pronounced depending on sensitivity and amount consumed.

Common symptoms may include:

• Itching, hives, or red patches on skin

• Tingling sensation around the mouth

• Nasal congestion, coughing, or wheezing

• Swelling of lips, face, tongue, or throat

• Abdominal pain, nausea, or vomiting

• Dizziness or lightheadedness

In some cases, exposure to allergens can lead to anaphylaxis, a severe allergic reaction that can interfere with breathing or circulation. Emergency care is required for suspected anaphylaxis.

How Shellfish Allergy Works

Food allergies occur when the immune system misidentifies specific proteins as harmful. Antibodies recognize the allergens and can trigger the release of chemical mediators such as histamine, which contribute to symptoms such as rashes, swelling, digestive upset, or respiratory difficulty.

First Aid Awareness & Management

Public allergy education often emphasizes:

• Avoiding known allergens through labelling, safe preparation, and food-sharing precautions

• Recognizing symptoms early and responding calmly

• Supporting the person’s breathing and comfort

Individuals who have been prescribed emergency medications for their allergies may carry them for personal use as directed by their healthcare professional. After a serious reaction, medical assessment is recommended to monitor for ongoing symptoms.

Prevention & Everyday Safety Tips

People with shellfish allergies manage risk through a combination of awareness and communication:

• Reading ingredient lists carefully

• Asking about cooking methods and cross-contamination risks at restaurants

• Informing hosts, coworkers, or food staff about allergies when appropriate

• Reviewing workplace or school allergy plans

• Considering travel preparations when visiting coastal or seafood-focused destinations

Even small traces of shellfish proteins can trigger reactions in some individuals, so prevention often focuses on attentiveness rather than avoidance of social settings.

FAQ

Can shellfish allergy develop later in life?
Yes. Some people develop shellfish allergies during adulthood, even if they previously ate shellfish without issues.

Are shellfish allergies the same as fish allergies?
No. Shellfish (e.g., shrimp, lobster, clams) and finned fish (e.g., salmon, cod) are different allergens. Some individuals react to one but not the other.

Can cooking remove shellfish allergens?
Heat does not reliably remove allergens. People with confirmed allergies still need to avoid exposure.

Do restaurants pose a higher risk?
Seafood restaurants can increase cross-contact risk due to shared surfaces, oils, or utensils. Asking questions and reading menus can help reduce exposure.

Is anaphylaxis common with shellfish?
Shellfish is a well-known trigger for severe reactions in some individuals. Rapid medical care is important for suspected anaphylaxis.

Educational Note

This content supports public and workplace allergy awareness and encourages informed steps to reduce accidental exposures and seek appropriate care when reactions occur.