Atopy or allergic defines the field that some people have inherited predisposition to develop allergies, which corresponds to an overreaction of the body against foreign substances in the environment, called allergens.
The allergic reaction is not immediately apparent, but after one or more contacts with the allergen (sensitization). It results in a manufacturing abnormal amounts of antibodies (immunoglobulin E) against the allergen.
Which releases the inflammatory effects of substances such as histamine and causes clinical disorders.
The occurrence of allergy is always the result of an interaction between genetic predisposition (atopy) and environmental.
Recent work suggests that there may, in atopic subjects, an imbalance in favor of certain immune cells involved in the production of antibodies of class E, at the expense of other immune cells to anti-inflammatory effects and anti-allergic.
This immune imbalance may be enhanced by better hygiene current, which could explain the significant recent increase in frequency of allergy in developed countries.
Allergies are very diverse: asthma, rhinitis, conjunctivitis, eczema, hives, digestive problems, angioedema ...
Allergens are also very varied: animal dander, insect venoms, dust mites, mold, food. A subject can become aware of atopic against several of them ...
An allergy can be suspected recurrence of symptoms (rhinitis, skin reaction ...) that breed in the same circumstances (presence of pollen, exposure to professional products ...).
To confirm the existence of an interrogation "police" is not enough.It must be demonstrated that the patient is sensitized to the allergen and, especially, is essential to connect the clinical with this awareness.
Usually, we start by injecting under the skin of the forearm or back, with a small needle, the most common allergens (mites, cat hair and dog, pollens, molds, ...) in small quantities to see if the patient is not sensitized against them, which would result in a skin wheal diameter exaggerated.
You can also:
- Use testing against several commercially available allergens (Phadiatop ®) - assay the antibody (immunoglobulin E) produced specifically against the allergen suspect - or even in some difficult cases (food allergies) cautiously reintroduce the allergen in question (challenge) to see if it really is the cause of symptoms.
Desensitization can be achieved by giving regular small amounts of the allergen, or under the skin, or as is increasingly common today in the language (mites, grass pollen, birch and ragweed ).
Because of their anti-inflammatory or anti-allergic, the administration of topical corticosteroids (asthma, eczema) or drugs that block histamine release (rhinitis, conjunctivitis) can bring relief.
In the absence of desensitization, allergy remains in good standing for life. But the intensity of allergic reactions can, for mysterious reasons, fluctuate over time.
Childhood diseases in atopic component may disappear at puberty or move to another allergic condition (after eczema, allergic rhinitis and asthma may, for example, appear).
Many allergies are mild, but some drug or food allergies can be serious because they can induce shock in lost circulation.
What should you do?
When one knows allergic, it is best to avoid as much contact with a known allergen, or at least minimizing its importance.
Food allergies in some of the young child, the school must be informed of the risk and the young scholar will always have with him an emergency kit containing adrenaline to guard against a possible allergic shock.
Anaphylactic shock is an extremely violent allergic reaction to an allergen (foreign substance in th...
Avian influenza: Definition Bird flu is an infection caused by a virus of the Orthomyxoviridae fami...
Alopecia: Definition Alopecia is a lack of hair on all or part of the scalp. The term comes from al...
Angina or "angina" is a lack of blood perfusion and thus oxygen to the myocardium (or heart muscle) ...
Ankle sprain: definition The sprain is a torn ligament. In the case of a simple distension, it is be...
Angina are commonplace due to infection, usually viral (red chest pain) or, less commonly, bacteria ...