Istanbul Kent University, Faculty of Pharmacy
"Allergies are an overreaction of our immune system to seemingly innocent triggers; early diagnosis and correct treatment can improve quality of life"
Title:
| Allergy, What are allergic reactions
| What are the Types of Allergy
| What are Allergy Symptoms
| What are the allergic reactions seen on the skin
| What are the Risk Factors for Allergy
| What are the ways to prevent allergies
| Allergy Diagnosis
| Seasonal Allergy
| Allergic Asthma
| Allergic Cough
| Allergic reactions due to nutrition in children
| Importance of Microbiota in Allergy
| Allergy Treatment
| Home Treatment
| What Happens If Allergy Is Not Treated
| When to see a specialist for allergies
Allergy, What are allergic reactions
Allergies are your body's reaction to a foreign protein. Usually these proteins (allergens) are harmless. If you are allergic to a certain protein, your body's defence system (immune system) overreacts to the presence of the protein in your body. An allergic reaction is the way your body reacts to an allergen. If you are allergic, when you first encounter a particular allergen, your body responds by creating immunoglobulin E (IgE). Your immune system makes antibodies to create IgE. IgE antibodies bind to mast cells (allergy cells) that live in the mucus membranes in your skin, respiratory tract (airways) and the mucus membranes in the hollow organs that connect from your mouth to your anus (gastrointestinal or GI tract). Antibodies find allergens in your body and help remove them by taking them to the mast cell (allergy cell) where they bind to a special receptor. This causes the allergy cell to release histamine. Histamine is what causes your allergy symptoms.
What are the Types of Allergy
There are many different types of allergy. Some people are allergic to medicines, dust, pet dander, pollen from poisonous stinging animals or mould. Others are allergic to latex, certain medicines or insect stings.
Food allergies are also common. Any food can cause an allergic reaction, but the eight most common food allergens are eggs, milk, peanuts, tree nuts, fish, shellfish, wheat and soy.
What are Allergy Symptoms
The severity of symptoms during an allergic reaction can vary greatly. Some of the symptoms of an allergic reaction include
- Itchy, watery eyes
- Itchy nose
- Sneezing
- Runny nose
- Rashes
- Hives (a rash of raised red spots)
- Inflatable
- Redness
- Agri
- Tongue swelling
- Cough
- Throat closure
- Wheezing (whistling sound when breathing)
- Chest tightness and breathlessness
- Feeling of faintness, dizziness, or ‘fainting’
Some of these symptoms may indicate a life-threatening allergic reaction.
What are the allergic reactions seen on the skin
Our skin can react to allergens such as rashes, hives, swelling, redness. These symptoms are usually the response to factors such as dust, pollen, sun, pets, etc. that we are affected by the environment.
What are the Risk Factors for Allergy
Certain risk factors can increase the risk of developing allergies. Common allergy risk factors include:
- Family history of allergy
- Having asthma or eczema
- Living in an urban area
- Age, as allergies are more likely to occur in childhood and adolescence
What are the ways to prevent allergies
The best way to prevent allergies is to avoid exposure to the allergen. Depending on what your allergy is, you can take the following measures:
- Taking medication recommended by a health care provider or allergist
- Avoiding certain food allergens
- Exercising indoors during the peak allergy season
- Regular vacuuming and dusting of carpets
- Installing high-efficiency particulate air (HEPA) air filters in your home and cleaning the vents frequently
Allergy Diagnosis
When diagnosing allergies, the allergist will first want to know your symptoms. They will probably ask how often you experience symptoms and how severe they are. They will also ask about your home and work environment to identify potential allergens you are exposed to. Your health history and whether you have family members with allergies are also important parameters during the diagnosis. A physical examination of your eyes, ears, nose and lungs will also be carried out. For respiratory symptoms of allergy, such as a cough or runny nose, they may perform a lung function test to determine how well you are breathing air through your lungs. The allergist may recommend allergy testing to determine which allergens you are allergic to to ensure an accurate diagnosis.
Common allergy diagnostic tests include:
Skin Prick Test: This involves exposing the skin to a small amount of an allergen. If you are allergic to a particular allergen, the exposed skin will swell, redden and itch within 15 minutes.
Blood Test: A blood test called specific IgE (sIgE) involves taking a sample of your blood. This test measures levels of allergen-specific antibodies to confirm allergy.
Intradermal Test: Similar to a skin prick test, an allergen is injected into the top layer of the skin. This test can be done if the skin prick test is negative but an allergist suspects you have allergies.
Patch Test: Commonly used to determine which allergen causes contact dermatitis, this test involves applying small patches containing the allergen to your skin, covering it with a bandage, and examining it for an allergic reaction 48-96 hours later. If you are allergic to this allergen, a rash will develop.
In some cases, a health care provider may also perform additional tests. Using tests such as X-rays of your chest and sinuses can help them rule out other conditions or better assess the extent of your symptoms.
Seasonal Allergy
Seasonal allergies, also known as seasonal allergic rhinitis or hay fever, occur in the spring, summer or autumn months when trees, weeds and grasses are pollinated.
Spring allergies are caused by tree pollen and typically occur from February to early summer. However, more than two thirds of people with spring allergies experience symptoms every year.
Late spring and early summer allergies are typically caused by grass pollen and can cause year-round symptoms, especially in warm or tropical climates where pollen counts are high.
Late summer and autumn allergies are usually caused by weed pollen, especially ragweed pollen, which reaches its highest levels in many parts of the United States from early to mid-September.
Mould spores can cause allergies in spring, summer and autumn. For people living in buildings with high humidity levels, they can cause allergies throughout the year.
Allergic Asthma
Allergic asthma is the most common type of asthma. About 90% of children with childhood asthma have allergies, compared with about 50% of adults with asthma. Symptoms associated with allergic asthma occur after breathing in things called allergens (or allergy triggers), such as pollen, dust mites or mould. If you have asthma (allergic or non-allergic), it usually gets worse after exercising in cold weather or breathing in smoke, dust or fumes. Sometimes even a strong odour can trigger it.
Because allergens are everywhere, it is important for people with allergic asthma to know their triggers and learn how to prevent an attack.
Allergic Cough
An allergy cough occurs when you inhale a substance (allergen) that your immune system recognises as dangerous, even though it is not. The cough is typically dry and unproductive, i.e. it does not produce mucus. It is sometimes described as having a ‘barking’ or ‘hacking’ sound.
Tree and grass pollen, pet dander, dust mites or mould are just some of the allergens that can cause an allergy cough.
Allergic reactions due to nutrition in children
Food allergy, which is defined as an adverse immune response to food proteins, is increasing in children as a result of studies. It affects 6% of children and 3-4% of adults. The role of breast milk in preventing the development of allergy in children is controversial. Food-induced allergic reactions in children cause many symptoms and disorders affecting the gastrointestinal system, respiratory tract and skin. These symptoms are mediated by immunoglobulin (IgE)-mediated and non-IgE-mediated mechanisms. The cornerstone of food allergy treatment is the strict elimination of foods from the diet.
Importance of Microbiota in Allergy
The role of the microbiome in the molecular mechanisms underlying allergy has become very important in recent years. Studies increasingly suggest that altered composition of the microbiota or dysbiosis may lead to local and systemic alteration of the immune response to specific allergens. In this context, a link has been established between lung microbiota and respiratory allergy, between skin microbiota and atopic dermatitis, and between gut microbiota and food allergy. The composition of the human microbiota is dynamic and depends on host-related factors such as diet, diseases and lifestyle. The microbiota colonises the skin and mucosal surfaces and its key aspects have a significant impact on human physiology and health.
Allergy Treatment
The best way to manage an allergy is to reduce exposure or avoid allergens altogether. However, this is not always possible. Medicines and treatments can help.
If over-the-counter (OTC) medications do not relieve your allergy, a health care provider may recommend prescription medications. These include the following:
Oral corticosteroids: Reduces inflammation and stops severe allergic reactions
Antihistamines and decongestants
Leukotriene modifiers: Block chemicals (leukotrienes) that cause symptoms
Mast cell stabilisers: Prevent your body from releasing histamine and are most effective when used before exposure to the allergen
Home Treatment
In most cases, allergies can be managed at home using the following home treatments.
Corticosteroid creams and nasal sprays: Nasal corticosteroid sprays work by reducing swelling and inflammation. They are considered the best treatment for nasal allergies. Over-the-counter corticosteroid creams and ointments are also available to relieve redness and itching.
Antihistamines: Antihistamines relieve allergy symptoms by blocking the effects of histamine. They are available over the counter as pills, chewable tablets, eye drops and nasal sprays.
Decongestants: Decongestants reduce swollen tissue by narrowing the blood vessels in the nose. This helps you breathe more easily.
Many people also get rid of allergies by using nasal irrigation devices such as neti pots and bulb syringes. These devices can effectively flush the nasal passages and filter out allergens
It is important to avoid using tap water when washing the nose. Tap water is not considered safe to use as a nasal rinse. It is not sufficiently purified or filtered and may contain bacteria and protozoa. It is always recommended to use sterile or distilled water when using nasal wash devices.
Immunotherapy
If you have allergies triggered by environmental factors such as pollen, dust mites, bee venom or pet dander, your healthcare professional may recommend immunotherapy.
Immunotherapy exposes you to a small amount of allergen over time so that your immune system becomes desensitised or develops a tolerance to the allergen.
The two most common types of immunotherapy are allergy shots and sublingual (under the tongue) immunotherapy (SLIT).
What Happens If Allergy Is Not Treated
Untreated allergies can worsen and more severe allergy attacks can occur over time. These frequent or prolonged allergic reactions can also weaken your immune system and set the stage for dangerous complications such as bacterial or fungal infections of the sinuses, lungs, ears or skin.
Allergy sufferers who do not receive adequate treatment are at risk of developing allergies to more substances, leading to more attacks. For people with asthma, untreated allergies can lead to increasingly frequent and severe asthma attacks.
When to see a specialist for allergies
- You have symptoms such as a runny or stuffy nose, cough or watery eyes that last for more than 3 months and make it difficult for you to work or sleep.
- You have a lot of sinus infections, headaches, nasal congestion or ear infections.
- You snore or have difficulty staying asleep.
- You have other health problems such as heart disease, thyroid disease, diabetes, glaucoma, high blood pressure, enlarged prostate, liver disease or kidney disease. It may not be safe to treat allergies yourself with over-the-counter medicines if you have them. Talk to your doctor before taking them.
- Children and elderly people with allergies should see a doctor before starting treatment.
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