Definition | Allergy | Futura Health

Theallergy is an immune reaction to a certain substance, such as pollen, the appendages pets or certain foods. It is a deregulation of immune system which no longer tolerates substances which are harmless to the body: allergens.

Causes of allergies

The allergies are often linked to predispositions genetics, but environmental factors may play a role:

• pollution;
• food ;
• excess hygiene …

The frequency allergies has been on the rise for several decades in western countries.

Allergy symptoms

The reaction is manifested by symptoms respiratory (sneezing, constriction of the airways, tearing, rhinitis, asthma) cutaneous (skin rash, urticaria), or generalized:anaphylaxis.

These symptoms are caused by the release ofhistamine in the bloodstream and represent the means available to the body to remove the foreign substance; they are also accompanied by the release ofimmunoglobulins IgE.

Allergy treatment and diagnosis

The importance of these symptoms may be lessened by the administration ofantihistamines. A desensitization is also possible. Allergy sufferers should avoid contact with allergenic substances.

In patients with symptoms that suggest an allergy, it can be diagnosed using blood tests and prick tests.

Wheat, eggs, fish, nuts can cause food allergies. © Evan Lorne, Shutterstock

The main allergies: pollen allergy and food allergies

The allergens that can cause allergies include:

• allergens that enter the body through the respiratory tract: animal hair, pollen, mites, mold;
• allergens that cause a reaction on contact: nickel, cosmetic chemicals, latex, chromium ;
• the venoms hymenoptera (bees, wasps …);
• medication : antibiotics, anti-inflammatory non-steroid;
• food (milk, eggs, peanuts…) in the food allergy.