Many people have been allergic since childhood and suffer from diseases such as allergic rhinitis, asthma, atopic dermatitis or allergic conjunctivitis. According to London Allergy and Immunology Centre, 44% of adults and 50% of children in the UK have one or more allergies. The number of people with allergies is rising by about 5% every year. Allergies cost the NHS around £900 million each year, mostly through prescriptions. This makes up 10% of GP’s prescription budget. What exactly causes people to be allergic? Can allergies be prevented or cured?

Causes of allergic reactions

Allergic reactions can be induced by exposure to specific substances, and the process of inducing allergies can be divided into two stages:

1. When the body comes into contact with these allergens, the immune system treats these substances as foreigners and increases the amount of immunoglobulin E (IgE) in the body to resist foreign invasion. These immunoglobulins E will adhere to mast cells, but an allergic reaction will not occur at this time.
   
2. When the human body comes into contact with the same allergen again, the mast cells that already contain immunoglobulin E will be stimulated and release histamine, causing allergic phenomena such as redness, itching, and increased mucus.

What is immunoglobulin E?

Immunoglobulin E is a protein considered an antibody and is the agent that triggers allergies. If the human body is exposed to an allergen, the immune system will produce a large amount of immunoglobulins to fight the allergen. These immune proteins will remain in the body and cause an allergic reaction the next time the allergen is encountered. Every allergen can bind to immune proteins. For example, immune proteins that bind to pollen will only cause allergic reactions to pollen. In other words, different allergens have different immune proteins, which is why there are so many allergen testing items. .

What are the common allergens and symptoms?

Allergic reactions may affect the trachea, sinuses, nasal cavity, and skin. Some people have mild allergies, while others have severe symptoms that may be life-threatening. Depending on the allergen, patients may have different allergic symptoms:

1. Pollen allergy: sneezing, itchy nose, runny nose, red and swollen eyes.
   
2. Food allergies: Foods such as peanuts, nuts, eggs, seafood and gluten can easily trigger allergies and cause mouth irritation, swelling of the throat or lips, red rash, and shortness of breath.
   
3. Allergy to insect bites: The bite area will be red, swollen and stinging, itching all over the body, a red rash, cough, chest pressure or shortness of breath.
   
4. Drug allergy: Common drug allergies include penicillin and analgesic and anti-inflammatory drugs. Patients may experience symptoms such as rash, itchy skin, facial edema, or shortness of breath.
   
5. Other environmental allergens: such as dust mites, animal dander (cat, dog), detergents, mold. If inhaled, it may cause itching, runny nose, or watery eyes; contact may cause symptoms such as skin redness, swelling, and itching.
   
6. Atopic dermatitis: Itchy, red and swollen skin, forming flakes or lumps of dandruff.

Severe allergies may cause anaphylactic shock

Most allergies cause some mild discomfort but are not life-threatening. However, a small number of patients may suffer from severe allergic reactions due to food or insect bites, leading to anaphylaxis. The following are the symptoms that patients with anaphylaxis may experience:

1. Lose consciousness
2. Blood pressure drops
3. Shortness of breath
4. Dizziness
5. Feel sick and vomit
6. Heartbeat

Don’t know what you’re allergic to? Allergen testing uncovers culprit

There are many types of allergens. If you want to find out which substances you are allergic to, you may consider doing an allergen test. Allergen testing is mainly for patients with food allergies or contact allergies, such as allergies caused by eating specific foods, or allergies caused by skin contact with certain substances; the allergens of patients with nose allergies are mostly dust mites, dust and animal skins The causes of allergies are similar to those of dandruff, so the test is of little practical significance.

Allergen testing can be divided into two types. One is to check the concentration of immunoglobulin E by drawing blood, and the other is to apply allergens to the skin through patches or injections to observe whether there is redness or swelling on the skin.

However, the test results do not 100% reflect the true condition of the body, and it is especially difficult to determine when testing for food allergies. Some people learn that they are allergic to seafood when they have their blood drawn, but they have never experienced any allergic symptoms from eating seafood. This may be due to Some food allergies require immune proteins to reach a certain concentration to cause symptoms.

Allergen testing is divided into acute and chronic

Allergen testing in the market can be divided into two types: acute and chronic. Most people are more familiar with acute allergen testing. This kind of testing is for IgE immune globulin, mainly inhaled allergens, such as dust mites, mold, pollen, Animal skins, etc.

The principle of chronic allergy is to focus on food. Different from acute allergen testing, chronic allergen testing measures immunoglobulin G (IgG). However, immunoglobulin G is a normal immune response. No matter what food you eat, immunoglobulin G will be produced. Therefore, the most accurate test is through IgE immunoglobulin.

How to prevent allergies?

Although allergies are not as harmful to the body as diseases, the frequent runny noses or red and swollen eyes are also very troublesome for many people, and even greatly affect the quality of life. “Hello Doctor” also provides the following 4 suggestions to help you prevent and reduce the occurrence of allergies and improve the quality of your daily life:

1. Avoid allergens and keep the environment tidy: Keeping the environment dry and tidy can help reduce the amount of allergens such as dust, pet hair, dust mites, mold, etc., and reduce the frequency of allergy attacks.
   
2. Please inform if you have a drug allergy: If you have ever had an allergy after taking a drug, you should record it accurately so that you can inform the doctor or pharmacist when you seek medical treatment or receive medicine in the future to avoid causing drug allergies again.
   
3. Record daily diet and activities: Some people suffer from allergic reactions for a long time, but they have no way of knowing what substances they are allergic to. It is recommended to record the daily diet or activities to find out the main causes of allergens from the details of life.
   
4. Long-term control through medication: Most allergic symptoms will recur repeatedly depending on time (such as season, day and night), environment and other factors. Allergy symptoms can be stably controlled through long-term use of steroid nasal sprays, steroid inhalers and other medications. Reduce the frequency and severity of allergic reactions.