safe

Vodič za lekare

Partners

Provincial Secretariat for Urban Planning, Construction and Environmental Protection
Provincial Secretariat for Urban Planning, Construction and Environmental Protection
European Affairs Fund of Autonomous Province of Vojvodina
European Affairs Fund of Autonomous Province of Vojvodina
City of Sombor
City of Sombor
Local Government of Baja
Local Government of Baja
dobri susedi

Allergic conjunctivitis

  • Proneness to allergies is related to the atopic syndrome. Back in the 70's, the notion of the atopic syndrome encompasses allergic reactions manifested on mucosae or skin, i.e. the changes of the parts of the body that communicate directly with the environment. They included: atopic dermatitis (in German speaking countries we talk about neurodermatis or endogenous eczema), allergic rhinitis, allergic conjunctivitis, asthma.
    Depending of hereditary and external provocative factors, the allergy is manifested either on the mucosa or skin. Only in 15-30% of the cases the symptoms appear both on the skin and mucosa. Most typically, the two forms interchange. The changes appear almost always between the ages of six and seven. Allergens can be of different types: inhaled, nutritive, climate conditions, stress, etc. The atopy is related to the "atopic gene" on chromosome 14q11.2 (Lancet, 1996), which means that the proneness to augmented "faulty" defence function is hereditary. Such augmented, yet "faulty" defence function is spurred into action by a "trigger". We have already said that each substance we come in contact with through our mucosa or skin is testing our immune system. The defence mechanism diligently analyses, recognises and removes everything that can damage the organism. Unfortunately, however, such reaction is inadequate in people suffering from this disease. Their immune system activates a whole range of defence reaction. People with atopy have an innate functional disorder when it comes to certain types of leucocytes, i.e. there is no regular control of antibody production. The amount of antibodies is increased, i.e. certain IgE fractions. Should a person have elevated level of IgE antibodies in blood and there is no record of allergies in the family history, it is most likely a latent form of allergy. This means that the person has not yet been in contact with a trigger which would set off the allergy mechanism. If, on the other hand, the family history has recorded information about an allergy, a blood sample can be taken from the umbilical cord at birth and the IgE antibody level can be determined.

    The early allergic reaction sees the allergen penetrate into the conjunctiva. The plasma cells produce antigen-specific IgE antibodies that bond with the mastocytes. When the next contact with the antigen occurs, it bonds with the IgE antibodies fixed on the mastocytes. The result of the reaction is mastocyte decomposing and the release of histamine, eosinophilic chemotactic factors, prostaglandin and leucotriene. Histamine causes oedema and redness, prostaglandins pain and oedema, leucotrienes chemotaxis, oedema and increased vascular propulsion.

    Eozinophils also feature receptors for IgE antibodies, which are disintegrated following a new contact with the antigen. In this process, they release inflammatory mediators, which leads to an even worse clinical picture. Particularly prominent is the major basic protein. It is the most responsible for creating allergic reaction by re-triggering the mastocytes degranulation, the process which lasts even after the antigen has been removed.

     

 
EUThis website has been produced with the financial assistance of the European Union. The content of the website is the sole responsibility of the European Affairs Fund of Autonomous Province of Vojvodina and can under no circumstances be regarded as reflecting the position of the European Union and/or the Managing Authority.