Symptoms
Allergies can affect various organ systems:
- Skin: hives with wheals, itching, redness, swelling (edema), eczema.
- Nose: runny and stuffy nose, sneezing, itching.
- Airways: bronchoconstriction, shortness of breath, cough, asthma.
- Digestive tract: diarrhea, vomiting, indigestion.
- Eyes: Allergic conjunctivitis, redness, tearing.
- Cardiovascular: Drop in blood pressure, rapid heartbeat
- Mouth, mucous membrane: Burning, furry feeling, swelling.
- Throat: Itching, scratching, swelling.
Allergies are becoming increasingly common. In many countries, over a quarter of the population is affected.
Causes
In an allergy, the immune system reacts specifically to a substance that is foreign to the body and usually harmless, but does not cause an immune response in most people. These substances are called allergens. Typical triggers include, for example:
| Allergens | Examples |
| Pollen | Grasses, trees, shrubs |
| Food | peanuts, crustaceans, kiwi, milk, eggs, celery |
| Natural products | Latex |
| Metals, jewelry | Nickel |
| Insecticide | Bees, wasps, hornets |
| Medicines | Antibiotics, NSAIDs |
| Fungi | Molds |
| Animals | Cat allergy |
| Preservative | Parabens |
| Other | House dust mites, fragrances |
Allergy usually develops after repeated contact with an allergen. The process that leads to allergy is called sensitization. The reaction may be immediate or delayed after a few days, depending on the type of allergy.
Complications
The allergic reaction can be life-threatening in rare cases. Anaphylaxis is a severe, generalized hypersensitivity reaction that results in symptoms such as shortness of breath, low blood pressure, swelling, and abdominal cramps. Other complications:
- Bronchial asthma
- Cross-reactions
- Job loss, psychosocial problems, reduced quality of life.
Diagnosis
Diagnosis is made in medical treatment on the basis of clinical symptoms, patient history, with a skin test (prick test, epicutaneous test), blood test (antibody detection) or provocation test.
Nonpharmacologic treatment
- Avoid allergens
- Carry allergy emergency kit and allergy passport with you
- Keep allergy diary (allergy calendar)
Drug treatment
Specific immunotherapy or hyposensitization involves administering allergens subcutaneously and sublingually, among other methods. Unlike all other agents, immunotherapy is causally effective, not just symptomatic, and can produce a complete or partial cure. Antihistamines:
- Are antagonists at the histamine H1 receptor, thus reversing the effects of histamine. They can be administered topically or systemically. 2nd generation agents, such as cetirizine, loratadine, and fexofenadine, are considered better tolerated than older drugs and need to be taken only once daily because they have a long duration of action.
Mast cell stabilizers:
- Such as cromoglicic acid and ketotifen inhibit the release of inflammatory mediators.
Cortisone tablets:
- Such as prednisolone are used only in severe conditions, such as severe asthma or anaphylaxis. For local treatment, creams, asthma sprays and eye drops are available, which are better tolerated.
Sympathomimetics:
- Epinephrine is the first-line agent for a severe allergic reaction (anaphylaxis). Beta2 sympathomimetics are inhaled for bronchodilatation.
Leukotriene antagonists:
- Such as montelukast are approved for the treatment of hay fever in addition to asthma. They cancel the effects of pro-inflammatory leukotrienes.
Herbal medications:
Anti-IgE antibodies:
- Omalizumab binds IgE antibodies and is approved for the treatment of severe allergic asthma.
Numerous alternative medicine therapeutics are available for prevention and treatment.
