Allergy and Clinical Immunology

Allergies are caused by an excessive reaction of the immune system to substances from the environment (such as food, pollen, dust, or animal fur), which are normally harmless.

Substances that cause allergies are referred to as allergens.

These include in particular:

• Grasses and pollen (fescue, cock's foot, timothy and meadow grass / birch, hazel, alder, oak and beech) 
• Moulds, mites
• Animal fur/hair, saliva and skin cells (rodents, rabbits, cats, dogs) 
• Foods (cow's milk, eggs, peanuts, nuts, fish, crustaceans, soy and wheat, celery, citrus, fruit)
• Insects - bee, wasp stings
• Medications (antibiotics - penicillin and sulfonamides, iodine, anti-inflammatory drugs)
• Objects with which the allergic person is in contact (nickel, preservatives, latex) 

Allergic diseases can be divided into:

• Respiratory allergies
  • Allergic rhinitis (hay fever)
  • Asthma bronchiale (bronchial asthma)
• Skin allergies
  • Atopic eczema (dermatitis)
  • Hives (urticaria) - itchy skin rashes
• Food allergies
• Contact allergies - allergic reaction on the skin after contact with an allergen (nickel, cosmetics)
• Allergies to insect stings (bees, wasps)
• Allergies to cold or sun

Anaphylactic shock is a life-threatening condition of excessive reaction of the whole body to an allergen.

Symptoms: intense itching, swelling (lips, tongue, throat), difficulty breathing, wheezing, nausea, abdominal cramps, malaise, loss of consciousness and rapid and irregular heartbeat. In such cases, it is necessary to call an ambulance and the patient should be given an adrenaline pen, which the allergic person should always carry with them.

During the examination, the allergist thoroughly consults the patient - asks about the difficulties, symptoms and duration of the disease. He is interested in the medications taken.

Allergy symptoms are associated with the presence of allergens. Therefore, the allergist asks about the presence of pets, dust and mold at home and at work. For example, pollen and grasses are characterized by seasonality.

After a clinical examination (listening to the patient, examining the skin), blood samples are taken.

• Blood test results usually show increased antibodies (e.g. IgG and IgE antibodies and white blood cell count)
• Skin test (PRICK test) - in which allergens are applied directly to the skin and the presence of allergy is determined
• Allergist avaluates of additional examinations:
  • Pulmonary function examination (spirometry, lung capacity)
  • Imaging examination: X-ray, MRI and CT 

Treatment of allergies is difficult - the reason why the allergy occurs is unknown. When treating allergic diseases, we focus on two main principles:

• Minimize contact with the allergen (avoid substances that cause allergies)
• Relief from symptoms and setting up long-term treatment

Treatment must be long-term and the patient is treated even during the period when the pollen season is not in progress and when he has no symptoms.

Basic medications include:

• Antihistamines - medications that prevent mast cells (a type of white blood cell) from releasing histamine and triggering an allergy
• Antileukotrienes - medications that block leukotrienes (substances from white blood cells that cause inflammation and swelling) - in asthma, they help keep the airways open
• Corticosteroids - reduce inflammation and suppress immunity
• Decongestants - substances used as a spray or drops to relieve swollen nasal mucosa (taken for a maximum of 7 days)

Long-term therapy includes:

• Allergen immunotherapy (administration of small amounts of allergen to allow the immune system to "get used to" the allergen - also called desensitization or hyposensitization)
• Biological therapy (biological drugs that, for example, act directly on IgE antibodies)