Food Allergies

Food allergy will occur when the body’s immune system responds in an unusual way after eating certain foods. Symptoms may appear almost instantly after eating or develop within a couple of hours.

Although not exclusive some of the common foods associated with allergies include:

• Milk allergy is an atypical immune system response to milk and products containing milk. It's one of the most common food allergies in children. Cow's milk is the usual cause of milk allergy, but milk from sheep, goats, buffalo, and other mammals also can cause a reaction. An allergic reaction usually occurs soon after you or your child consumes milk. Signs and symptoms of milk allergy range from mild to severe and can include wheezing, vomiting, hives and digestive problems. Milk allergy can also cause anaphylaxis — a severe, life-threatening reaction. Avoiding milk and milk products is the primary treatment for milk allergy. Fortunately, most children outgrow milk allergy. Those who don't outgrow it may need to continue to avoid milk products.
• Eggs allergy is one of the most common allergy-causing foods for children. Symptoms usually occur a few minutes to a few hours after eating eggs or foods containing eggs. Signs and symptoms range from mild to severe and can include skin rashes, hives, nasal congestion, and vomiting or other digestive problems. Rarely, egg allergy can cause anaphylaxis — a life-threatening reaction. Egg allergy can occur as early as infancy. Most children, but not all, outgrow their egg allergy before adolescence.
• Fish allergy is unlike other food allergies, which are typically first observed in babies and young children. An allergy to fish may not become apparent until adulthood; in one study, as many as 40 percent of people reporting a fish allergy had no problems with fish until they were adults. Having an allergy to a finned fish (such as tuna, halibut, or salmon) does not mean that a person is also allergic to shellfish (shrimp, crab, and lobster). While some allergists recommend that individuals with a fish allergy avoid eating all fish, it may be possible for someone allergic to one type of fish to safely eat other kinds. If someone is allergic to a specific type of fish, their allergy specialist can help them determine whether other varieties may be safe to eat, so they can take control of their fish allergy and start enjoying life again.
• Shellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. Marine animals in the shellfish category include crustaceans and molluscs. Examples are shrimp, crab, lobster, squid, oysters, scallops, and snails. Shellfish is a common food allergy. Some people with shellfish allergy react to all shellfish, while others react to only certain kinds. Reactions range from mild symptoms — such as hives or a stuffy nose — to severe and even life-threatening.
• Nut allergy. If a customer is allergic to nuts, eating or even just being exposed to a small amount can trigger an allergic reaction. Nuts are one of the most common triggers for anaphylaxis and a severe reaction that can be life threatening. An allergy to nuts develops when the body's immune system becomes over-sensitive to a protein in a nut. Being exposed to the nut causes an allergic reaction. Nut allergies are also on the increase. Allergy UK Peanuts reminds us that peanut allergy affects around 2% (1 in 50) of children in the UK and has been increasing in recent decades. Also, approximately 30-40% of children with peanut allergy will have an allergy to at least one tree nut. An allergy to peanuts does also increase the likelihood of an allergy to sesame and lupin. Many children with a nut allergy will need emergency medical attention at some point. Very sensitive people can have a reaction if they are exposed to tiny traces of nuts: for example, through eating, breathing or simply touching a nut. Nut allergy is most common in infants and young children, but sometimes appears for the first time in adults. People can be allergic to different types of nuts. The most common ones are peanuts, almonds, Brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pistachios, and walnuts.
• Wheat allergy is an allergic reaction to foods containing wheat. Allergic reactions can be caused by eating wheat and, in some cases, by inhaling wheat flour. Avoiding wheat is the primary treatment for wheat allergy, but that isn't always as easy as it sounds. Wheat is found in many foods, including some you might not suspect, such as soy sauce, ice cream and hot dogs. Medications may be necessary to manage allergic reactions if you accidentally eat wheat. Wheat allergy is sometimes confused with celiac disease, but these conditions differ. Wheat allergy occurs when your body produces antibodies to proteins found in wheat. In celiac disease, a specific protein in wheat called gluten causes a different kind of abnormal immune system reaction.
• Soya allergy is more prevalent in infants and young children than in older children. Most children eventually outgrow their allergy to soya, although some individuals remain allergic to soya throughout their lives. When a person with a soya allergy is exposed to soya, proteins in the soya bind to specific IgE antibodies made by the person’s immune system. This triggers the person’s immune defences, leading to reaction symptoms that can be mild or very severe. Soya beans are a member of the legume family. Beans, peas, lentils, and peanuts are also legumes. Individuals with soya allergy are more likely to be allergic or sensitised to other major allergens including peanuts, tree nuts, egg, milk, and sesame than to non-peanut legumes such as beans, peas and lentils.
• Strawberry allergy. It is possible to be allergic to strawberries, although this allergy is much less common than many other dietary allergies. Having a strawberry allergy means that a person’s immune system reacts badly to a specific protein that is present in this fruit. Heating strawberries will distort the proteins in them, so some people with a strawberry allergy may be able to eat cooked strawberries. Certain foods, including strawberries, citrus fruits, and tomatoes, can cause allergy-like symptoms without a person having a true allergy to them. Customers who suspect that they may have a strawberry allergy can discuss their symptoms with a doctor and possibly have an allergy test for confirmation.
• Sesame allergy is an allergy to sesame protein after eating the sesame seed. According to NHS Allergy Northwest sesame allergy has become more common over the past ten years and is estimated to affect 1 in 100 people. One in three children with multiple food allergies may have sesame allergies. People can also develop delayed skin reactions to using creams and toiletries containing sesame seed oil. Most people with sesame seed allergy will only have mild reactions. Severe reactions affecting the child’s breathing occur in about 15% of cases, particularly in those with poorly controlled asthma. More severe reactions may also occur if the child has a cold, following intense exercise, at times of stress or in teenagers after drinking alcohol. Children with sesame seed allergy may also be allergic to other seeds, peanuts and tree nuts.

Customers / Patients can access factsheets on the different foods and how it can affect a person by visiting Allergy UK Food Allergy.

Common symptoms include:   

• Abdominal pain or diarrhoea.
• Feeling sick or vomiting.
• Itchy skin or rash.
• Runny nose and sneezing.
• Wheezing and coughing.
• Severe symptoms could lead to anaphylaxis.

IgE-mediated food allergy: This is the most common type, triggered by the immune system producing an antibody called immunoglobulin E (IgE). Upon subsequent exposure to the same food allergen, the allergen binds to the IgE antibodies on the mast cells, triggering these cells to release various chemical substances, including histamine and other inflammatory mediators. This release of chemicals leads to the symptoms associated with an allergic reaction. Symptoms of an IgE-mediated food allergy occur a few seconds or minutes after eating. Symptoms can range from mild to severe and may include skin reactions (such as itching, hives, or eczema), digestive issues (like vomiting, diarrhoea, or abdominal pain), respiratory symptoms (such as coughing, wheezing, or difficulty breathing), swelling of the lips, tongue, throat, or face, and in severe cases, anaphylaxis, a potentially life-threatening reaction affecting multiple systems of the body.

Non-IgE-mediated food allergies: This refers to allergic reactions that occur without involving Immunoglobulin E (IgE) antibodies. Unlike IgE-mediated allergies, these reactions involve different components of the immune system and have a delayed onset.

Mixed IgE and non-IgE-mediated food allergies: Some individuals may experience a combination of both IgE-mediated and non-IgE-mediated responses to certain foods. This type of allergy can present with both immediate (IgE-mediated) symptoms, such as hives or swelling, as well as delayed (non-IgE-mediated) symptoms, such as gastrointestinal disturbances or skin issues.

Food allergy testing and diagnosis: It’s essential for individuals with food allergies to be aware of their specific allergens, read food labels carefully, avoid cross-contamination, and have an emergency action plan in case of accidental exposure. Consulting with a healthcare professional and undergoing allergy testing can help determine specific food allergies and appropriate management strategies.

Diagnosing a food allergy is crucial for several reasons:

• Accurate identification of triggers.
• Prevention of severe reactions.
• Avoidance of unnecessary dietary restrictions.
• Finding the right support and guidance.

If a customer is looking for help and advice or information, they can call Allergy UK’s Helpline on 01322 619898. They can support the customer through their food allergy journey and advise on their nearest NHS allergy clinic or consultant.

Types of food allergy testing

There are several types of allergy tests used to diagnose different types of allergies, including food allergies. Some common food allergy tests include:

• Skin Prick Test (SPT): This test involves placing a small amount of allergen extract on the skin (usually on the forearm) and then pricking or scratching the skin to allow the allergen to enter. If a person is allergic to the substance, a raised, red, itchy bump (called a wheal) will appear within about 15-20 minutes.
• Blood Tests: Blood tests measure the levels of specific IgE antibodies to various allergens in the blood. These tests can identify specific allergens that may trigger allergic reactions.
• Oral Food Challenge: This involves consuming small amounts of a suspected food allergen under medical supervision to confirm or rule out a food allergy. It’s considered the most accurate way to diagnose a food allergy but is performed in a controlled setting due to the risk of severe reactions.
• Elimination Diet: This isn’t a test in the traditional sense, but a method used to identify food triggers by eliminating suspected allergens from the diet and then gradually reintroducing them while monitoring for reactions.

The choice of allergy test often depends on the type of allergy suspected, the individual’s medical history, and the allergens being tested for. These tests should always be conducted and interpreted by a healthcare professional, such as an allergist or immunologist.

Top tips to advise your customers with a food allergy:

•  Keep a diary of the food(s) which causes the allergy.
•  Consider checking the ingredients on food labels which you need to avoid.