Allergy can be described as an abnormal response of the immune system. Defence substances in our blood called immunoglobulins have the task of recognising foreign substances in the body and eliminating their harmful effects. The immune system of people with allergies develops an excessive reaction to substances in the environment that are generally harmless (allergens), such as pollen, mould and animal hair. In people without allergies who encounter an allergen (a substance that causes allergy), this response is kept under control.
Allergy is an excessive sensitivity of the body to substances that do not harm other people under similar conditions. One in every four people experiences allergic diseases at some point in their lives. The risk of developing an allergy to something is 30% in a person with one allergic parent, rising to 50–60% in people whose mother and father are both allergic. Besides genetics, factors such as air pollution, industrial chemicals, cigarette smoke and infection also contribute to the development of allergy. Rates of allergic disease also vary according to lifestyle and environmental differences.
Some people's bodies react when exposed to certain substances (such as pollen, foods or the sun) by inhalation, ingestion or skin contact. This substance or these substances are called allergens, 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 to special cells in the tissues and blood, especially mast cells. Histamine and many other substances are released from mast cells (cells involved in the body's defence), and these substances cause the symptoms of allergy (such as rash, itching and a runny nose).
The most common symptoms of allergic reactions can be listed as follows:
• Itching, watering and redness of the eyes
• Itchy, runny nose
• Redness, weals and itching of the skin
• Feeling tired and/or unwell
• Cough
• Wheezing
When allergens are inhaled, increased mucus production and inflammation can develop in the nasal mucosa. This leads to symptoms such as a runny nose, itching and sneezing. Watering, stinging and itching of the eyes may accompany this. Asthma can also be triggered during allergic reactions. When the allergen is inhaled and reaches the lungs, breathing difficulties may occur due to swelling. Although not all asthma attacks are due to allergy, allergy plays an important role in many asthma patients.
Allergies caused by foods may be accompanied by nausea, vomiting, diarrhoea and cramping abdominal pain. In cow's milk allergy seen in babies, skin lesions such as eczema may develop in addition to intestinal and stomach complaints. Allergic reactions following bee stings or other insect bites usually cause local swelling, redness and pain.
Why a person develops an allergic reaction cannot be fully answered. However, genetic and environmental factors are known to affect the risk of developing allergy. Allergy can occur in any age group and in either sex. In childhood, food allergies and allergic eczema are more prominent, while with advancing age allergic rhinitis and conjunctivitis are seen, which may be accompanied by asthma. Drug allergies and occupational allergies are also more common in adulthood.
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 are seen throughout the body:
• Difficulty breathing
• Wheezing
• Hoarseness
• A feeling of something stuck in the throat
• Redness all over the body
• Weals and itching
• Tingling in the hands, feet and lips
• A drop in blood pressure is among the symptoms observed.
All of these signs can be life-threatening. For this reason, immediate and correct intervention in anaphylaxis is very important.
Allergic skin diseases are the most common skin diseases. These include serum sickness, Quincke's oedema (angioedema), urticaria (hives), eczema and contact dermatitis. Finding the cause of allergic skin diseases is quite difficult. For this purpose, the patient and their environment are investigated very carefully. Various skin tests are performed. If necessary, the patient is removed from their environment for a while. An attempt is made to find the factor causing the allergy. These factors may include pollen, various foods, house dust, certain medicines and intestinal parasites. Heredity, body constitution and nervous state, i.e. psychological causes, also play a major role in allergic diseases.
Apart from these diseases of the skin, there are also skin manifestations of various internal diseases. For example, in diabetes various signs are seen on the skin (such as urticaria, boils and gangrene). There are also malignant and benign tumours of the skin. Skin cancers are the least malignant of all cancers, and complete cure is also possible.
Depending on the type of skin disease, different types of lesions are seen on the skin. These include scratch marks, papules (small raised bumps on the skin), pustules (pus-filled blisters), boils, ulcers, tubercles (pointed skin protrusions), erythema (redness), hyperpigmentation (increased skin colour), hypopigmentation (decreased skin colour), desquamation (shedding of the skin), crusting and tumour formation. One or several of these lesions may be present together in a skin disease. Skin diseases are easy to diagnose. When necessary for a definitive diagnosis, a sample is taken from the affected area and subjected to pathological examination. Treatment is not always easy and varies according to the type of disease.
In allergic skin diseases, after a dermatological examination, in addition to the necessary laboratory tests, "prick test" and "patch test" methods are performed and evaluated in our clinic. The results are compared with the patient's living conditions, and solutions based on preventive treatment are developed.