John KIRAGU
- Apr 14
- 5 min read

Understanding and managing food allergies and intolerance

"Food intolerance is not the same as food allergy, as it affects the digestive system and causes chemical reactions within a few hours after eating." - John K.

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Food allergies happen when the body's immune system perceives the protein found in food as a threat. The symptoms associated with food allergies affect various parts of the body, such as itchy sensations in the mouth, ear, or throat; swelling of the face around the lips, eyes, and tongue; angioedema; vomiting; and raised itchy red rashes ("hives" or urticaria).

Severe allergic reactions (anaphylaxis) can cause difficulty breathing, loss of consciousness, lightheadedness, and tightness and swelling of the throat, persistent dizziness, and difficulty talking, which can be life-threatening. Food intolerance is not the same as food allergy, as it affects the digestive system, causes chemical reactions, and brings symptoms within a few hours after eating. It does not cause anaphylaxis and may not cause symptoms if you eat a small amount of food.

Common Types of Food Intolerances

Histamine

Histamine is a naturally occurring chemical reaction in foods such as pineapples, cheese, avocados, chocolate, and bananas. The buildup of histamine in the body triggers an immune response resulting in symptoms such as headache, skin irritation, shortness of breath, and diarrhea. It is recommended to eliminate diets with high histamine intolerance and then add them back after some time to give you an idea of which foods your body can tolerate and which cause symptoms.

Gluten

Gluten intolerance is linked with adverse reactions to gluten, a type of protein found in barley, wheat, and rye. Gluten intolerance is associated with symptoms of celiac disease, an autoimmune disease that damages your digestive system and is accompanied by various symptoms such as digestive issues, mood changes, and skin problems. In addition, it may contribute to various fatigue, such as chronic pain, psychological conditions like anxiety and depression, and inflammation. Celiac disease can also result in a higher risk of iron deficiency (anemia), which affects the ability to produce healthy red blood cells, resulting in serious side effects like decreased energy and fatigue.

Lactose

Lactose intolerance happens when your small intestine does not produce enough lactase enzymes to digest lactose, which is found in milk sugar. Lactose intolerance is associated with symptoms such as bloating, constipation, tummy pain, and farting. It may also cause long-lasting symptoms such as rush (eczema), joint pain, feeling tired, headaches, and difficulty concentrating. Foods that contain lactose include dairy products such as milk, butter, cream, cheese, yogurt, and other processed foods like cereals, salad and sauce dressings, and protein shakes.

Lactose intolerance can be prevented by minimizing the consumption of foods containing lactose or by removing these foods completely from your diet. Certain gastrointestinal problems, such as celiac disease and bowel inflammatory diseases like ulcerative colitis and Crohn’s disease, may contribute to food intolerance.

Food Allergy

Almost all foods can result in an allergic food reaction, but there are certain foods that are responsible for most food allergies. The antibody called immunoglobulin E reacts with food proteins and mistakenly identifies them as a threat, which causes several chemicals to be released especially histamine. Histamine is involved in various symptoms that occur during allergic reactions, as it facilitates the expansion of small blood vessels and the surrounding skin to swell up and become red.

It also enhances the production of mucus in your nose lining that results in a burning sensation and itching, and affects your skin nerves, resulting in itchiness. In a severe allergic reaction (anaphylaxis), the immune system releases a high amount of histamine and other chemicals into your bloodstream, which results in severe symptoms. There are two types of food allergies: immunoglobulin E (IgE)-mediated and non-IgE-mediated. Immunoglobulin E-mediated reactions are where the body produces IgE antibodies that react with specific foods.

The allergic reaction takes place a few hours after consuming the food allergen and involves various symptoms, including anaphylaxis. The non-IgE-mediated allergy involves digestive or skin symptoms, and it does not make immunoglobulin E antibodies. Its symptoms include diarrhea and vomiting, which can happen up to 3 days after consuming the food allergen.

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Here are some common food allergies:

Eggs

The immune system reacts to allergens, resulting in inflammatory reactions and the release of chemicals. The protein that causes an allergic reaction in your body can either be egg yolk or egg white, but typically egg white is more likely to cause allergic reactions. Depending on the immune system, egg allergies can cause diverse symptoms ranging from mild to severe. These symptoms include:

Floppiness and paleness, especially with kids
Swelling of the throat
Difficulty breathing
Collapse or persistent dizziness
Swelling of lips, face, and eyes
Abdominal pain
Tingling mouth

The best way to manage food allergies due to eggs is to avoid all diets containing eggs and egg products.

Cow milk

Cow milk allergies occur when your immune system reacts with the milk proteins casein and whey and identifies them as harmful. Milk allergies can be both non-immunoglobulin E (IgE)-mediated and IgE-mediated. Cow milk allergies related to IgE have various signs and symptoms, such as swelling, vomiting, hives, and anaphylaxis. A non-IgE allergic reaction is associated with gut-based symptoms such as diarrhea, inflammation of the gut walls, and vomiting. If you have an allergic reaction due to milk, the best treatment is to avoid all diets containing it.

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These include milk powder, butter, cheese, margarine, ice cream, and yogurt. Anaphylaxis due to milk allergy requires special treatment with epinephrine (adrenaline), and the symptoms occur soon after milk intake and include facial flushing, shock, itching, and a swollen throat that makes it difficult to breathe. You should seek immediate medical attention whenever you experience milk allergic reactions with severe symptoms.

Fish

A fish allergy occurs when the body perceives fish proteins as a threat, causing severe allergic reactions. Your immune system produces histamine and other chemicals that cause the symptoms of a fish allergy. The symptoms associated with a fish allergy include vomiting, diarrhea, and anaphylaxis. These severe symptoms include trouble breathing, collapsing, hoarseness, wheezing, and tightness in your throat. It is recommended to carry an epinephrine auto-injector in case you accidentally eat fish. The only way to treat a fish allergy is to avoid foods that contain fish, such as salmon, tuna, tilapia, perch, hake, trout, and grouper.

While there is no treatment for food allergies and food intolerance, the following strategies will help you manage and prevent your condition:

Carry your epinephrine auto-injector in case of severe allergic reactions.
Avoid the intake of food without clear information on ingredients or possible contamination with food allergens.
Avoid restaurants where you can be exposed to food allergens unintentionally.
Inform your chef, server, family, or friends who may prepare a meal about your food allergy.
Avoid cross-reactivity and cross-contact where allergens can be transferred from foods that contain allergens to those that do not contain them.
Read the label carefully to avoid the intake of foods containing allergens where it has been used as an ingredient.
Recognize your signs and symptoms.

Food allergy is different from food intolerance; food allergy is associated with the immune system, while food intolerance or sensitivity happens when your body lacks essential enzymes to break down foods, causing a digestive response. Food intolerance involves symptoms such as bloating, stomach pain, diarrhea, irritable bowel syndrome, headaches, and recurrent mouth ulcers. Food allergy involves symptoms like feeling lightheaded, coughing, having raised rashes, wheezing, having breathlessness, and feeling sick.

The most common foods that cause allergic reactions include cow's milk, fish, eggs, peanuts, wheat, soy, and shellfish. Since there is no cure for food allergies and no medicine to prevent allergic reactions, it is important to avoid foods that contain proteins that cause allergic reactions.