Allergology

Causes of allergic reactions

To date, allergic reactions are one of the most common medical problems. The main causes of their occurrence in humans are considered to be genetic predisposition and the influence of environmental factors.
Normally, the immune system protects the human body from harmful substances such as: bacteria and viruses. In some cases, the immune system begins to react even to potentially safe foreign substances, so-called allergens.x

These reactions are usually overexpressed and are accompanied by the release of certain chemicals - histamines, which cause the appearance of allergy symptoms.
The most common allergens include:

Medications
Dust
Food
Insect venom
Mold
Wool and epithelium from pets and other animals
Pollen.

Some people have allergic reactions to high and low temperatures, sunlight and other environmental factors. In some cases, the appearance of allergy symptoms can provoke friction of the skin: clothes or hands.
Diseases of an allergic nature are not usually transmitted from generation to generation, i.e. they are not inherited. However, if both parents suffer from allergies, it is likely that the child will also be prone to allergic reactions. The likelihood of acquiring an allergy is greater if it is present in the mother. Allergies can cause many diseases such as sinusitis, eczema, bronchial asthma, etc.

Symptoms

The hierarchy of appearance of allergy symptoms depends largely on the site of allergen entry or initial contact with the allergen.

For example:

Allergens that enter by inhalation often cause nasal congestion, nasal itching, mucus production, coughing and wheezing.
Allergens that come in contact with the eyes can cause itching, lacrimation, redness and swelling in the eyelid area.
Eating foods that are allergens to a particular person can trigger nausea, vomiting, abdominal pain, diarrhea, cramps, and other serious and life-threatening reactions.
Allergens that come in contact with the skin can cause skin rashes, hives, itching, blisters, and skin detachment.
Drug allergies usually manifest as generalized or widespread reactions, which can lead to a range of symptoms.

Investigations and testing

When allergies are suspected, a medical facility will examine the patient, clarify complaints and medical history.
In order to differentiate an allergic reaction from another disease, allergy tests may be necessary.

For example, food poisoning may cause symptoms similar to alimentary or food allergies. Some medications (such as aspirin and ampicillin) can cause skin rashes that are not allergic. The cause of a runny nose or cough may not be an allergy, but an infection.

Skin tests are the most common way to diagnose allergies. The prick test (needle test) is one of the skin allergy tests. A small amount of a substance, a potential allergen, is applied to the skin and then a prick is made on the skin so that the substance penetrates under the skin. The skin is monitored over a period of time. Allergy to a particular substance is indicated by reactions such as redness and swelling. This type of allergy test can be used to diagnose allergies in young children and infants.

Other types of skin allergy tests include application tests and intradermal testing. Laboratory blood tests are performed for additional information:

Immunoglobulin E blood test
A general blood test to determine the level of white blood cells and eosinophils

In some cases, the doctor may ask to avoid contact with potential allergens or conversely contact these substances in order to assess the patient's reaction and condition. This is called “use or avoidance testing” Such tests are used to evaluate reactions to foods or medications. The doctor may also evaluate the patient's reaction to physical factors, such as heat, cold, or other potential allergy triggers. In some cases, the potential allergen is dissolved and injected into the conjunctival sac cavity (under the lower eyelid) and the patient's reaction is evaluated. This test is the most sensitive and is performed in a medical office setting in the presence of a physician.

Treatment

Severe acute allergic reactions (anaphylaxis) are treated with a medication called epinephrine (adrenaline), the immediate administration of which can save the patient's life. If anaphylaxis occurs, an ambulance should be called immediately and the patient should go to hospital.

The best way to reduce the severity of allergy symptoms is to avoid contact with potential allergens. This is especially true in the case of food and drug allergies.
There are a number of medications that prevent the onset of allergies and reduce the severity of its manifestations. The selection of the drug is carried out by a doctor, based on the specifics of the disease, symptoms, age and general condition of the patient.

Some diseases of allergic nature, such as asthma, allergic rhinitis or eczema, may require completely different treatment.

Medications that are used to treat allergies include the following:

Antihistamines
There are different groups of antihistamine medications. Some of them are sold in pharmacies without a prescription, for the purchase of others - a prescription is required. Produce antihistamines in various forms:

Capsules and tablets
Eye drops
Injections
Syrups
Nasal spray

Corticosteroids

Hormonal drugs with anti-inflammatory activity are available in various forms such as:

Creams and ointments for the skin
Eye drops
Nasal spray
Solution for inhalation

Patients with severe allergies may be prescribed corticosteroids in tablets or injections, in short courses.

Decongestants

Decongestants (decongestants) help relieve nasal congestion. Decongestants in the form of a nasal spray should not be used for more than a few days, as this can have the opposite effect and make nasal congestion worse. Decongestants in tablet form do not cause these reactions. People with high blood pressure, heart disease, or an enlarged prostate gland should use decongestants with caution.

Other medications

Leukotriene inhibitors are medications that block inflammatory factors and substances that activate or trigger the development of an allergic reaction. Taking the medications zafirlukast and montelukast are recommended for people with asthma, household and external allergies.

Allergy vaccination

Allergy vaccination (immunotherapy) is recommended if contact with a potential allergen cannot be avoided or if allergy symptoms are difficult to control. Allergy vaccination blocks the body from reacting to the allergen. The patient will receive a daily injection of the allergen. Each dose will be slightly increased from the previous dose until the maximum dose is reached. This method of treatment is not indicated for all patients. Allergy vaccination is carried out in a specialized medical institution under medical supervision.

Prognosis

In most cases, it is possible to cope with allergic reactions with the help of medication. Some children can outgrow allergies, especially food allergies. However, the substance that sensitized the body can affect a person throughout his or her life. Allergy vaccination is the most effective method of treating pollinosis (seasonal allergy to blossoms) and severe allergic reactions to insect stings. Allergy vaccination is not used to treat food allergies because of the risk of developing a severe reaction. Allergy vaccination may take time to achieve results, but in most cases it is an effective treatment method. Allergy vaccination can cause unwanted or side effects, such as hives or rashes, and can also cause an acute allergic reaction, anaphylaxis

Possible complications of allergies?

Anaphylaxis (a life-threatening allergic reaction)
Breathing problems during an allergic reaction
Drowsiness or other side effects from taking the medication.

When to see a medical professional?

It is necessary to make an appointment with a doctor if:

Severe allergy symptoms occur
Allergy treatment no longer works

Prevention

Breastfeeding can prevent or reduce allergies if the mother continues to breastfeed her infant from 4 to 6 months of age. However, a breastfeeding mother's poor diet can trigger allergies in the baby. (However, changing the mother's diet during pregnancy or while breastfeeding may not help avoid allergies).

In most cases, changing the baby's diet or using a special milk formula will not prevent allergies. If a parent, sibling or other family member suffers from allergies or a condition of an allergic nature, such as eczema, you should discuss feeding your child with your pediatrician.

It is a proven fact that a child's contact in the first year of life with pets or other allergens, such as dust mites, can prevent the development of some allergies later in life. This observation became known as the “hygiene hypothesis”. It originated from observing infants on farms, who tend to be less likely to suffer from allergies than children growing up in “sterile” conditions. Older children, however, do not benefit from this contact.

If an allergic reaction does occur, timely treatment and cessation of contact with the allergen will prevent similar reactions in the future.