Shellfish Allergy

Overview

Shellfish allergy is an atypical response by the body's immune system to proteins found in certain marine animals, including crustaceans and mollusks. Examples of shellfish are shrimp, crabs, lobster, squid, oysters, scallops, and snails. Shellfish allergy is a common type of food allergy, and it can cause a range of symptoms, from mild reactions like hives or a stuffy nose to severe and potentially life-threatening reactions. If you suspect you have a shellfish allergy, it's essential to consult with a healthcare provider for proper testing and guidance on avoiding future reactions.

Understanding the disease

Symptoms

The symptoms of shellfish allergy can vary from person to person, ranging from mild reactions to severe and potentially life-threatening allergic reactions. Some common symptoms of shellfish allergy include:

• Hives
• Itchy, irritated skin
• Nasal stuffiness (congestion)
• Swelling of the lips, face, tongue, and throat, or other parts of the body
• Wheezing or trouble breathing
• Coughing and choking or a tight feeling in the throat
• Belly (abdominal) pain, diarrhea, nausea, or vomiting
• Dizziness, lightheadedness, or fainting
• Anaphylaxis (a severe, potentially life-threatening allergic reaction that requires immediate medical attention) It is important to talk to a healthcare provider if you suspect you have a shellfish allergy, as tests can help confirm the allergy and guide you in avoiding future reactions.

Risk Factors

You are at increased risk of developing shellfish allergy if allergies of any type are common in your family. While people of any age can develop shellfish allergy, it is more common in adults, particularly women. A family history of allergy, asthma, or other allergic conditions can also increase the risk of developing a shellfish allergy.

Development

Shellfish allergy develops when the body's immune system mistakenly identifies a certain protein in shellfish as harmful, causing an immune system overreaction. The immune system produces immunoglobulin E (IgE) antibodies to protect against this allergen. When a person comes in contact with the shellfish protein again, these antibodies signal the immune system to release chemicals such as histamine into the bloodstream, leading to an allergic reaction. The various types of shellfish, including crustaceans and mollusks, contain different proteins, and an individual may be allergic to one or multiple types of shellfish.

Assessment and Diagnosis

Triage

You should see a doctor if shellfish allergy is suspected when you experience symptoms shortly after eating shellfish or coming into contact with it. These symptoms may include hives, itchy skin, nasal stuffiness, swelling of the face and throat, wheezing, abdominal pain, diarrhea, nausea, vomiting, dizziness, or a tight feeling in the throat. If you experience severe symptoms, such as difficulty breathing, a fast heartbeat, or a loss of consciousness, seek emergency treatment immediately, as this may indicate anaphylaxis, a potentially life-threatening allergic reaction.

Diagnosis

To diagnose a shellfish allergy, your healthcare provider will likely start by asking about your symptoms and performing a physical exam to rule out other medical problems. A history of allergic reactions shortly after exposure to shellfish can indicate an allergy, but symptoms could also be caused by other factors such as food poisoning. Allergy testing is the most reliable way to confirm the cause of your symptoms, so your provider may recommend skin prick tests or blood tests to measure your immune system's response to shellfish proteins. In some cases, medically supervised food challenges may be necessary to confirm the diagnosis. If you have a severe allergic reaction (anaphylaxis), you should carry an epinephrine injection at all times and seek emergency medical care after using it.

Management and Treatment

Home Remedies

If you have a shellfish allergy, it is important to avoid all shellfish and products containing shellfish. In case of a reaction, you should seek medical attention immediately.

Treatment

There are two main treatments for shellfish allergy: avoidance and epinephrine (adrenaline) injection. Avoiding all shellfish and products that contain shellfish is the only way to prevent an allergic reaction. It's important to read food labels carefully and be cautious when dining out, as cross-contamination can occur. In case of a severe allergic reaction (anaphylaxis), an epinephrine (adrenaline) injection is required. If you are at risk of having a severe allergic reaction to shellfish, you should always carry injectable epinephrine (Auvi-Q, EpiPen, others). After administering the injection, seek immediate medical attention and go to the emergency room. An anaphylactic reaction to shellfish is a medical emergency that requires prompt treatment.

Preparing for medical consultation

Preparing for an appointment for a shellfish allergy involves taking certain steps to ensure a productive and safe visit. Here are some suggestions:

1. Make a list of your symptoms: Before your appointment, create a list of symptoms you have experienced after consuming shellfish. This will help you discuss your allergic reactions in detail with your healthcare provider.
2. Note the severity of your reaction: Be prepared to describe the severity of your allergic reaction, including any symptoms you experienced, how long they lasted, and whether you needed medical attention.
3. Keep a food diary: Maintain a food diary for a few weeks before your appointment, noting any instances where you suspect you may have consumed shellfish or shellfish products. This will help your healthcare provider understand your dietary habits and potential triggers.
4. Learn your allergy symptoms: Familiarize yourself with the common symptoms of a shellfish allergy, such as hives, itching, swelling, stomach cramps, diarrhea, and difficulty breathing. This knowledge will help you recognize an allergic reaction and report it to your healthcare provider.
5. Bring your medications: Bring a list or the actual medications you currently take for your allergies, asthma, or other related conditions. This will help your healthcare provider understand your medical history and provide appropriate advice or treatment recommendations.
6. Prepare questions: Write down any questions or concerns you have about your shellfish allergy, such as how to avoid shellfish, what to do in case of an allergic reaction, or if there are any new treatments available.
7. Inform your healthcare provider about recent exposure: If you have been exposed to shellfish recently or suspect you have had an allergic reaction, inform your healthcare provider before your appointment. This will help them prepare for your visit and provide appropriate guidance.
8. Follow your healthcare provider's advice: After your appointment, follow your healthcare provider's advice regarding your shellfish allergy. This may include avoiding shellfish, carrying an epinephrine auto-injector, and monitoring your symptoms. Remember that it is important to consult with a healthcare professional for tailored advice and guidance specific to your individual needs.