Allergy can be described as an abnormal response of the immune system. The immune system of individuals with allergies develops an excessive reaction to usually harmless substances (allergens) in the environment such as pollen, mold, animal hair. Allergic skin diseases are more common in all age ranges from children to the elderly due to excessive urbanization, rapid increase in negative environmental factors, and the increasing shift away from natural nutrition.
What is Allergy?
The body’s immune system recognizes any molecule that is not stored in its memory as “foreign” and takes action to keep it under control. In some people, the immune system reacts at a higher level and in a more complex way to molecules in the environment, such as house dust and pollen, which most people are not affected by. In these cases, we speak of hypersensitivity. Allergy can be defined as the body’s abnormal response to a “stranger”.
In recent years, there has been an increase in the frequency of allergic diseases in our country and all over the world.
What are the Causes of Allergy?
Studies have shown that genetic predisposition is an important factor in the development of allergy in a person. Individuals whose parents have allergic diseases may develop more allergic diseases.
Apart from genetic factors, environmental factors can also play a role in allergy development. Frequent exposure to any allergen may cause more reactions, i.e. more allergic diseases. The dense presence of allergens in the living environment may cause allergic reactions to be observed more frequently and severely.
The rate of exposure to allergens is higher in urban centers than in rural areas. The rate of development of allergic diseases also varies according to lifestyle and environmental differences.
How Does Allergy Occur?
Some people’s bodies react to certain substances (such as pollen, food, sun) when exposed to them by inhaling, swallowing or skin contact. This substance(s) is called an allergen and the reaction shown by the body is called an allergic reaction.
In an allergic reaction, the body starts to produce a special type of antibody called immunoglobulin E (IgE). IgE binds to the allergen and special cells in the tissue and blood, especially mast cells. Histamine and many other substances are released from mast cells (a cell involved in human defense cells) and these substances cause allergy symptoms (rash, itching, runny nose).
What are the Symptoms of Allergic Reactions?
The most common symptoms of allergic reactions can be listed as follows:
- Itching, watering and redness in the eyes,
- Itching in the nose, runny nose,
- Skin rashes, blisters and itching,
- Feeling tired and/or sick,
- Cough
- Wheezing is wheezing.
When allergens are inhaled, mucus formation in the nasal mucosa increases and inflammation (inflammation) may develop. Symptoms such as runny nose, itching and sneezing are observed. Watery eyes, stinging and itching may also accompany this condition.
Who Has Allergic Reactions?
It is not possible to answer exactly why a person develops an allergic reaction. However, it is known that genetic and environmental factors affect the risk of developing allergies.
Allergy can occur in all age groups and genders. While food allergies and allergic eczema are at the forefront in childhood, allergic rhinitis and conjunctivitis are more common with age and may be accompanied by asthma. Drug allergies and occupational allergies are also more common in adulthood.
What are Allergic Skin Diseases?
Eczema (Atopic dermatitis):
It is seen with redness, scaling, dryness and itching on the skin. Detailed information can be found at What is Eczema (Atopic Dermatitis)?
Urticaria (hives) and angioedema: Hives, which appear as red and highly itchy areas on the skin, can be found in places on the body or can be seen throughout the body. In hives triggered by excessive stress as well as allergic background, it is important to find the underlying triggering cause as in all allergic diseases. You can find detailed information at What is Hives (Urticaria)? Angioedema is a medical emergency.
In angioedema, edema (swelling as a result of fluid escaping from the vessel walls into the tissue) develops in the deeper layers of the skin. Unlike hives, there is no redness or itching. Shortly after exposure to the allergen, swelling of the mucous membranes of the eyelids, lips, face and typically the throat is observed. The patient should be transported to a health center without delay, especially in the throat, as rapid swelling of the mucous membranes can lead to tracheal obstruction.
Contact dermatitis:
It is an itchy dermatitis caused by substances that come into contact with the skin. Contact substances can cause two types of dermatitis: irritant contact dermatitis and allergic contact dermatitis.
Irritant contact dermatitis is a type of dermatitis caused by irritants such as soap, detergents, solvents such as alcohol, which change the pH, moisture and structural integrity of the skin, which can be seen in everyone and occurs a few hours after contact. The structure of the skin in the contact area, its thickness, humidity, friction area, etc. determine the effect of the contact substance. Repeated contact (such as frequent use of soap, disinfectants) shows the effects of contact gradually increasing with drying, cracking and hardening of the skin.
Allergic contact dermatitis is a late-type hypersensitivity reaction that occurs within 48-96 hours after contact of previously sensitized skin with an allergen. Allergic contact dermatitis is more common in some parts of the body. Areas such as the neck, inside of the wrist, outside of the hands, armpits are some of the areas where allergic contact dermatitis is common. Dermatitis findings such as redness and itching following the use of wristwatch straps and hand-wrist jewelry are examples of the development of allergic contact dermatitis.
What is Anaphylaxis?
Allergic symptoms can be mild, moderate or severe. Anaphylaxis is a serious allergic reaction that develops rapidly and can cause death.
Symptoms occur throughout the body. These include:
- Difficulty breathing,
- wheezing
- Hoarseness
- Feeling stuck in the throat,
- A rash all over the body,
- Rash and itching,
- Tingling sensation in hands, feet, lips,
- A drop in blood pressure (blood pressure).
All these symptoms can be life-threatening. For this reason, it is very important to respond to anaphylaxis immediately at home.
What are Allergy Tests?
In order to prevent allergies, the cause of the allergy must first be clarified and exposure to this allergen must be reduced. For example, if a person is allergic to house dust, precautions should be taken against house dust in the environments where they live and work. Allergens can be detected by blood and skin allergy tests.
Allergy tests are usually performed for allergic rhinitis-conjunctivitis, atopic dermatitis, contact dermatitis, urticaria, asthma, insect bites, food and drug allergies.
Allergy tests are not tests that the patient can perform alone. Physicians who specialize in this field decide which one to perform after the medical history and examination of the patient and apply it.
What are Allergy Prevention and Treatment Options?
In the management of allergic symptoms, the first step is to avoid the triggering allergen if it can be detected; various systemic and topical medications and immunotherapy take place in the second step.
Immunotherapy, or vaccine therapy, is a long-term treatment that aims to change the immune system’s response to allergens. Desensitization (desensitization) is achieved by administering increasing doses of allergens to which the patient is sensitive. Immunotherapy can be performed against a single antigen and is a very long-lasting method. Since multiple allergens play a role in many allergic diseases, immunotherapy is not a widely used method today. However, it can be used in cases such as bee venom allergy.