Shellfish Allergy

Shellfish Allergies Are Usually More Common In Adult

What is Shellfish Allergy ?

Shellfish allergy is immunologically mediated reaction to shellfish which occurs within minutes to hours after taking shellfish. Even a small amount of food is sufficient to trigger allergy symptoms. In some individuals, a food allergy can cause severe allergy symptoms or even a life-threatening reaction called anaphylaxis.

Shellfish are not a kind of fish, but are simply water-dwelling animals. There are several kind of species including various species of molluscs, crustaceans, and echinoderms. Within the shellfish family, the crustacean group (shrimp, lobster and crab) causes the greatest number of allergic reactions. Many shellfish-allergic people can eat mollusks (scallops, oysters, clams and mussels) with no allergic reaction. Although true cross-reactions among shellfish are rare, they appear because various types of shellfish are often stored together in few restaurants and markets, causing cross-contamination.

Though most of the food allergy is usually more common in children but fish allergy is more common in adult. Shellfish allergies most frequently develop in adulthood.

Symptoms of Shellfish Allergy

The most common symptoms include:

Tingling sensation or itching in and around the mouth
Swelling of the lips, tongue, face, throat or other parts of the body
Hives, itching or eczema
Cough, wheezing or trouble breathing
Nasal congestion
Abdominal pain, nausea, vomiting, diarrhea
Dizziness, lightheadedness or fainting
Anaphylaxis

Causes of Shellfish Allergy

In food allergy, our immune system recognizes food as a harmful substance and react against it leading to symptoms of food allergy.

In Shellfish Allergy, our immune system recognize Shellfish as a harmful substance and react against it. After a sensitization phase, when shellfish is introduced for second time the body produces huge number of immunoglobulin E (IgE) antibodies to neutralize the protein (allergen) in shellfish. Cross linking reaction lead to degranulation of mast cell releasing large number of powerful chemical mediators including histamine and other chemicals leading to sign and symptoms of allergic inflammation.

Diagnosis of Shellfish Allergy

Till date there is no ideal test for shellfish allergy.

Clinical features of Shellfish allergy is very from person to person and in each episode of reaction the symptoms may be different. A surprising thing on shellfish allergist is that people who are allergic to shellfish don’t necessarily have to eat it to develop allergic reaction. They may react if they simply breathe fumes, or if their food came in contact with shellfish. A physician should consider the following:

Symptoms. Tell your physician /allergist, the symptoms you are experiencing.
Family history of allergies. Tell your physician whether other family members are suffering from any form of allergic disorders.
A physical examination. To find out any urticarial lesion in the body and to exclude other cause of similar symptoms.
A skin prick test. A skin prick test using food allergen can be performed. Expertise in this regard is necessary to perform skin test. A positive prick test is only indicate the people is sensitized to particular food allergen tested.
A blood test. A blood test can be performed to measure the allergen-specific immunoglobulin E (IgE).
Elimination diet.
Oral food challenge.

Treatment of Shellfish Allergy

Avoidance is the best preventive measure.

However an individual may unknowingly come in contact with the food and lead to allergic reaction.

For mild to moderate allergic reaction: over-the-counter or prescribed antihistamines are helpful.

For severe allergic reaction: If there is severe reaction or anaphylaxis one must inject adrenaline/ epinephrine in appropriate dosage. If someone has adrenaline autoinjector then he can use it otherwise one have to attend nearest hospital as early as possible. One must carry his adrenaline autoinjector all the time if an allergist prescribed it.

Prevention of Shellfish Allergy

Avoidance of the Shellfish is the best way to prevent shellfish allergy.

If you have food allergy, then follow these steps:

Know what you’re eating and drinking. Always read the food labels.
If you have already had a severe reaction/anaphylaxis, wear a medical alert bracelet or necklace that lets others know that you have a food allergy.
Have an action plan ready. Always have your epinephrine /adrenaline autoinjector with you.
Be careful while eating at restaurants.
Plan your meals and snacks before leaving home.

If your child has a food allergy, you must follow few steps to ensure your child is safe:

Always notify key people about the child’s food allergy.
Explain food allergy symptoms to persons who spend time with the child.
Have a written action plan.
Have your child wear a medical alert bracelet or necklace.

Food Allergy Mimickers

Common conditions that mimic food allergy include:

Lactase deficiency / lactose intolerance
Food poisoning
Celiac disease. sometimes called to as a gluten allergy
Sensitivity to food additives.eg sulfites used in dried fruit, canned goods
Histamine toxicity from certain not refrigerated fish

Read in-depth of Shellfish Allergy

To read details click on Read More

Point to be remembered in managing Food Allergy

Avoidance of the offending food is the best way to prevent food allergy. One must know the causative food to which he is allergic. A person with food allergy must be cautious when eating in restaurants and in social events.

If you have food allergy, then follow these steps:

Know what you’re eating and drinking. Always read the food labels while you eating something.
If you have already had a severe reaction/anaphylaxis, wear a medical alert bracelet or necklace that will alert others and you have a food allergy.
Have an action plan ready. Always have a action plan of your food allergy.
Have an Epinephrine / Adrenaline Autoinjector with you.
Be careful while eating at restaurants.
Plan your meals and snacks before leaving home.

If your child has food allergy, you must follow few steps to ensure your child is safe:

Always notify key people about the child’s food allergy. Inform your child care providers, school personnel, parents of your child’s friends and other adults who regularly interact with your child. Tell them that food allergy may be life threatening and may require urgent intervention to save life of the child.
Explain food allergy symptoms to persons who spend time with the child.
Have a written action plan.This plan should include the appropriate management strategies to care the child in case of food allergy and in emergency case of anaphylaxis. One copy of the plan must be given to school authority.
Have your child wear a medical alert bracelet or necklace to display that he/she has Food Allergy.

In-depth reading about of Shellfish Allergy

What is Shellfish Allergy?

Though most of the food allergy is usually more common in children but fish allergy is more common in adult. Shellfish allergies most frequently develop in adulthood.

Sometimes few people develop indigestion, gaseous distention of abdomen or diarrhea after taking some food but it may not be due to food allergy but another condition called food intolerance. This reaction is not immunologically mediated and it is less severe than allergy.

Cause of Shellfish

Risk factor for Shellfish allergy include:

Family history of Allergy. your family members are suffering from some form of allergies like asthma, eczema, urticaria, allergic rhinitis then you are at risk of developing food allergy.
If you are suffering from food allergy to one of the food items. If you’re already allergic to one food, then you are at risk of developing food allergy to other foods.
Age. Overall food allergies are more common in children. Your food allergy may disappear when you grow older. In most of the cases of food allergy to eggs, milk, soy and wheat in children may resolved automatically when they grow older. But an allergy to shellfish and nuts may remain lifelong.
Asthma. Asthma and food allergy can occur together. In such patient, both food allergy and asthma symptoms are more likely to be severe.

Symptoms of Shellfish Allergy

Symptoms of Shellfish allergy can ranges from mild allergic reaction to severe allergic reaction or even life-threatening reaction called anaphylaxis. Usually, food allergy symptoms develop within a few minutes to two hours after eating the offending food.

The most common symptoms include:

Tingling sensation or itching in and around the mouth
Swelling of the lips, tongue, face, throat or other parts of the body
Hives, itching or eczema
Cough, wheezing or trouble breathing
Nasal congestion
Abdominal pain, nausea, vomiting, diarrhea
Dizziness, lightheadedness or fainting

Anaphylaxis

In few individual, a food allergy can cause anaphylaxis. Life-threatening signs and symptoms of anaphylaxis include:

Respiratory distress
A swollen throat or the sensation of a lump in your throat
Shock with a severe drop in blood pressure
Rapid pulse
Dizziness, lightheadedness or loss of consciousness

Anaphylaxis is a medical emergency treatment. Emergency treatment with intramuscular epinephrine/adrenaline is crucial for the survival of patients. Anaphylaxis if untreated can lead to coma or even death.

Diagnosis of Shellfish Allergy

Till date there is no ideal test for shellfish allergy. . A physician should consider the following:

Symptoms.

Tell your physician /allergist, the symptoms you are experiencing. Tell your allergist about the possible food items, eating of which lead to start of your symptoms.
Family history of allergies.

Tell your physician whether other family members are suffering from any form of allergic disorders.
A physical examination.

To find out any urticarial lesion in the body and to exclude other cause of similar symptoms.
A skin prick test.

A skin prick test using food allergen can be performed. Expertise in this regard is necessary to perform a skin test. A positive prick test only indicates is sensitization.
A blood test.

A blood test can performed to measure the allergen-specific immunoglobulin E (IgE).
Elimination diet.

This can be done by first eliminating the suspected food items for 2-4 weeks then reintroducing the food items one by one to see when the symptoms return back. However, an elimination diet cannot distinguish true food allergy from food sensitivity. Another thing one must be kept in mind that if a person is already experienced severe allergic reaction or anaphylaxis, one must not do an elimination diet as it may be disastrous.
Oral food challenge.

Here the physician will give you a small but gradually increasing amount of Shellfish or Shellfish containing product to see whether the symptoms are occurring or not. One must be kept in mind that if a person is already experienced severe allergic reaction or anaphylaxis, one must not do oral food challenge test as it can be disastrous.

Treatment of Shellfish Allergy

Avoidance is the best preventive measure. However, an individual may unknowingly come in contact with the food and lead to an allergic reaction.

For mild to moderate allergic reaction: over-the-counter or prescribed antihistamines are helpful.

For severe allergic reaction: If there is severe reaction or anaphylaxis one must inject adrenaline/ epinephrine in an appropriate dosage. If someone has adrenaline autoinjector then he can use it otherwise one has to attend the nearest hospital as early as possible. One must carry his adrenaline autoinjector all the time if an allergist prescribed it.

How to Prevent Shellfish Allergy

Avoidance of the offending food is the best way to prevent food allergy. One must know the causative food to which he is allergic. A person with a food allergy must be cautious when eating in a restaurant and in social events.

If you have a food allergy, then follow these steps:

Know what you’re eating and drinking. Always read the food labels.
If you have already had a severe reaction/anaphylaxis, wear a medical alert bracelet or necklace that lets others know that you have a food allergy.
Have an action plan ready. Always have your epinephrine /adrenaline autoinjector with you.
Be careful while eating at restaurants.
Plan your meals and snacks before leaving home.

If your child has a food allergy, you must follow few steps to ensure your child is safe:

Always notify key people about the child’s food allergy. Inform your child care providers, school personnel, parents of your child’s friends and other adults who regularly interact with your child. Emphasize that food allergy may be life-threatening and may require urgent intervention.
Explain food allergy symptoms to persons who spend time with the child.
Have a written action plan. This plan should include the appropriate management strategies to care for the child in case of food allergy.
Have your child wear a medical alert bracelet or necklace.

Lifestyle and home remedies

Avoidance of the offending food in the utmost importance in food allergy.

Don’t assume offending food in any form. Always check food labels while you eating outside especially in restaurants and in social events.
If you are in doubt then don’t eat. One must keep in mind that even a very small amount of food particle can trigger symptoms of food allergy or may trigger anaphylaxis. So if you are in doubt then it is better to avoid the food.
Involve caregivers of the child. If your child has a food allergy, then you have to inform the school staff and other care givers of the child so that they can manage the child in case of any symptoms of food allergy.
Hand washing/ clean kitchen room.