Food Allergy

Food allergies happen when your body's immune system mistakenly reacts to a food. This happens soon after eating a certain food, even a tiny bit. Your body's response can cause different symptoms. These might include itchy skin rashes (hives), trouble breathing (because your airways swell), or stomach problems like nausea and diarrhea. In some people, a food allergy can lead to a very serious, life-threatening reaction called anaphylaxis. This is a medical emergency that needs immediate attention.

About 8 out of every 100 children under 5 years old have a food allergy, and about 4 out of every 100 adults do. While there's no way to get rid of a food allergy completely, some children do eventually stop having them as they grow older.

It's sometimes hard to tell the difference between a food allergy and a food intolerance. Both can cause uncomfortable symptoms, but a food intolerance isn't as serious. A food intolerance doesn't involve the immune system. It's more like a digestive problem, where your body has trouble digesting a certain food. So while both can make you feel bad, food intolerance doesn't involve the same kind of reaction that a food allergy does.

Food allergies can range from mild discomfort to a life-threatening emergency. Some people experience only minor reactions, while others face serious consequences.

Allergic reactions usually start within minutes to a couple of hours after eating the food that triggers the allergy. In rare cases, symptoms can appear several hours later.

Common symptoms of a food allergy include:

• Mouth: Tingling or itching sensations.
• Skin: Hives, itching, or eczema (a skin rash).
• Body parts: Swelling of the lips, face, tongue, throat, or other areas.
• Stomach: Belly pain, diarrhea, nausea, or vomiting.
• Breathing: Wheezing, stuffy nose, or trouble breathing.
• Other: Dizziness, lightheadedness, or fainting.

A severe allergic reaction, called anaphylaxis, can occur in some people. Anaphylaxis is a medical emergency and can be life-threatening. Symptoms of anaphylaxis include:

• Breathing: Difficulty breathing due to tightening of the airways. This might feel like your throat is closing or you have a lump in your throat.
• Circulation: Sudden drop in blood pressure (shock).
• Heart: Rapid heartbeat.
• Nervous System: Dizziness, lightheadedness, or loss of consciousness.

If you suspect a food allergy, it's essential to seek medical attention right away. Seeing a doctor or allergist as soon as possible after the reaction helps with diagnosis. Prompt medical care is crucial if you experience any symptoms of anaphylaxis, which include:

• Breathing problems: Trouble breathing or the feeling that your airways are constricting.
• Shock: A sudden, noticeable drop in blood pressure.
• Heart: A fast, racing pulse.
• Nervous system: Dizziness, lightheadedness, or loss of consciousness.

If you are having an anaphylactic reaction, call emergency services immediately. Prompt treatment is critical.

If you think you might have a food allergy, see a doctor or allergist as soon as possible after eating something that might have caused a reaction. The sooner you see a healthcare professional, the better. Ideally, go when the allergic reaction is happening, so they can observe it and help figure out what's going on.

Get immediate emergency medical help if you have any signs of a serious allergic reaction called anaphylaxis. This is a medical emergency. Symptoms include:

• Trouble breathing: Your airways might tighten up, making it hard to breathe or swallow. You might feel like you're choking or can't get enough air.
• Fast heartbeat: Your heart might beat much faster than usual.
• Dizziness or lightheadedness: You might feel faint, unsteady, or like you're about to pass out.

If you experience any of these symptoms, call 911 or your local emergency number right away. Don't delay. Anaphylaxis can be life-threatening.

Food Allergies and Similar Reactions

When you have a food allergy, your immune system mistakenly thinks a certain food or a substance in it is harmful. Your body's defense system then makes antibodies called immunoglobulin E (IgE) to target that food (the allergen).

The next time you eat even a small amount of that food, the IgE antibodies recognize it. This triggers your immune system to release chemicals like histamine into your bloodstream. These chemicals cause the symptoms of an allergic reaction.

Many common foods can trigger allergies:

• Seafood (shrimp, lobster, crab)
• Peanuts
• Tree nuts (walnuts, pecans)
• Fish
• Eggs
• Milk
• Wheat
• Soy

Pollen-Food Allergy Syndrome (Oral Allergy Syndrome):

This happens when someone with hay fever (allergic rhinitis) reacts to certain fresh fruits, vegetables, nuts, or spices. Their immune system mistakenly sees proteins in these foods as similar to proteins in pollens they're allergic to. This is called cross-reactivity.

Symptoms often appear when these foods are eaten raw or uncooked. Cooking can sometimes lessen the reaction.

Other Food Reactions:

Eating certain foods can sometimes cause uncomfortable symptoms like itching, lightheadedness, hives, or even anaphylaxis (a severe allergic reaction) during or after exercise. Avoiding these foods or eating a few hours before exercise might help prevent these problems.

Symptoms like nausea, vomiting, stomach cramps, and diarrhea can also be caused by food intolerances or reactions to other substances in food, not just allergies. A food intolerance might allow you to eat small amounts of the problematic food without a reaction, unlike a true allergy where even a tiny amount can trigger a reaction.

Sometimes, the problem isn't the food itself, but something used in its preparation. For example, you might be sensitive to an ingredient in the food that's causing the symptoms.

Conditions that can mimic food allergies:

Several conditions can cause symptoms that look like a food allergy:

• Enzyme Deficiency: Your body might not have enough of the enzymes needed to digest certain foods. Lactose intolerance, for example, is a lack of the enzyme lactase needed to digest the sugar in milk products. This leads to digestive problems like bloating, cramps, diarrhea, and gas.
• Food Poisoning: Bacteria in spoiled food can cause symptoms similar to an allergic reaction.
• Sensitivity to Food Additives: Some people react to substances added to food, like sulfites (used as preservatives). This can trigger asthma attacks or other symptoms.
• Histamine Toxicity (Scombroid Poisoning): Certain fish, like tuna or mackerel, that haven't been refrigerated properly can have high levels of histamine. This causes symptoms like those of a food allergy, but it's not an allergic reaction.
• Celiac Disease: This is an immune system response to gluten, a protein found in wheat, barley, and rye. Eating gluten damages the lining of the small intestine, preventing the body from absorbing nutrients. Although it involves the immune system, it's not a simple food allergy and doesn't cause anaphylaxis.

It's essential to see a doctor to determine the cause of your symptoms if you suspect a food allergy or intolerance. Proper diagnosis is crucial for managing your health.

Food allergies can run in families. If you have a family member with asthma, eczema, hives, or allergies like hay fever, you might have a higher chance of developing a food allergy yourself. Having an allergy to one food can also make you more likely to be allergic to another. Similarly, if you have other allergic reactions like hay fever or eczema, you're at a higher risk for food allergies.

Young children, especially toddlers and infants, are more prone to food allergies. As children get older, their digestive systems develop, and they're less likely to react to foods that trigger allergies. Luckily, many children eventually outgrow allergies to common foods like milk, soy, wheat, and eggs. However, severe allergies, like those to nuts and shellfish, often last a lifetime.

Having asthma can increase the risk of food allergies, and when both conditions are present, symptoms of both can be more severe.

Certain factors can also raise the risk of a severe allergic reaction called anaphylaxis. These include:

• Having asthma: If you have asthma, you're more likely to have a severe reaction to a food allergy.
• Being a child or teenager: Young people are more susceptible to severe reactions.
• Delaying treatment: If you delay using epinephrine (an emergency medication) to treat your food allergy symptoms, you could increase the risk of a serious reaction.
• Lack of skin symptoms: If your first symptoms aren't skin-related (like hives), a severe reaction might be more likely.

Food allergies can cause several problems. One serious complication is anaphylaxis. This is a very severe allergic reaction that can be life-threatening. It's important to know the symptoms and get immediate medical help if you think someone is having an anaphylactic reaction.

Another possible problem is a skin condition called eczema, also known as atopic dermatitis. Sometimes, a food allergy can trigger a skin rash or other skin problems like eczema. Eczema can cause itching, redness, and dryness on the skin.

Introducing peanut products early can help prevent peanut allergies.

A recent study looked at babies who were at higher risk for allergies, such as those with eczema (a skin condition) or an egg allergy, or both. These high-risk babies were either given peanut products regularly or not, from around four to six months old, until they were five years old. The results showed that babies who ate peanut products were significantly less likely to develop a peanut allergy – about 80% less likely.

This doesn't mean you should immediately start giving peanuts to every baby. It's always best to talk to your pediatrician about when and how to introduce potentially allergenic foods to your child.

If you or your child already has a food allergy, the best way to stay safe is to know what foods to avoid. This can be tricky, as some foods are hidden in other dishes, especially at restaurants. Knowing what you're eating is key.

How to stay safe with food allergies:

• Read food labels carefully. This helps you know what's in the food you're buying.

• Wear a medical alert bracelet or necklace if you've had a severe reaction. This alerts others to your allergy in case you can't communicate during a reaction.

• Be cautious at restaurants. Let the staff know about your allergy. Ask if the meal can be prepared without the food you can't eat, and confirm that no cross-contamination happened. Explain that you need to be very certain about this, as even a tiny bit of the allergen can cause a reaction. Don't hesitate to ask questions or request a different dish. Restaurant staff are usually happy to help if you're clear about your needs.

• Plan ahead. Pack your own meals or snacks if you're going out, especially to events or parties. If there are food items you can't eat, bring an alternative treat for yourself or your child to avoid anyone feeling excluded.

Protecting children with food allergies:

• Tell others about the allergy. Share this information with childcare providers, school staff, friends' parents, and any other adults who regularly interact with your child. Explain that an allergic reaction can be serious and needs immediate attention. Teach your child to ask for help if they react to food.

• Explain the symptoms. Teach those around your child how to spot signs of an allergic reaction, such as hives, swelling, or trouble breathing.

• Create an action plan. Write down what to do if your child has an allergic reaction. Include steps for calling for help and administering any necessary medications. Give a copy of this plan to school nurses and other caregivers.

• Consider a medical alert bracelet or necklace. This can list your child's allergy and explain how to provide emergency first aid.

Determining if you have a food allergy isn't always straightforward. Doctors use a combination of methods to figure out if a food is causing a problem. There's no single perfect test.

Understanding Your Symptoms: First, your doctor will need details about your symptoms. What foods seem to trigger problems? How much of the food do you eat before you have a reaction? The more information you give, the better they can understand the situation.

Family History: A family history of allergies can be a clue. If other family members have allergies, you might be more likely to have one too.

Physical Exam: A physical exam helps rule out other possible medical issues that might be causing your symptoms.

Blood Tests: A blood test can measure your immune system's response to certain foods. It looks for a type of antibody called immunoglobulin E (IgE). A sample of your blood is sent to a lab, which tests for potential allergens.

Elimination Diet: Sometimes, doctors recommend an elimination diet. This involves taking away suspected foods for a short time (a week or two), then slowly reintroducing them one at a time. This can help pinpoint which foods might be causing issues. However, this method isn't perfect. It can't distinguish between a true allergy and a food intolerance. If you've had a severe reaction to a food in the past, this method may not be safe.

Oral Food Challenge: Another way to test for a food allergy is an oral food challenge. This is done in a doctor's office, where you eat small amounts of the suspected food, gradually increasing the amount. If you don't have a reaction, it could mean that the food isn't causing problems.

Skin Tests: A skin prick test can also help. A tiny amount of the suspected food is placed on your skin. If you have an allergy, a small bump or reaction will appear. A positive skin test alone, however, isn't enough to confirm a food allergy. More tests and information are needed.

Important Note: No single test is definitive. Diagnosing a food allergy often requires combining information from different tests and your medical history. It's vital to work closely with your doctor to determine the best course of action for you or your child.