Click here to see in dynamic what happens when the allergic attack is prolonged or come back after you have red the detailed description of this process written below.
When you are exposed to the allergen for a longer period of time you generally notice that your symptoms are getting more severe. Why is this happening?
Because your immune system continues to bring into play more soldiers trying to win the battle with what it thinks is an aggressive enemy. The action of the new cells brought to the site of the allergic conflict aggravates the symptoms you experienced during the acute attack (if you remember these symptoms were caused mainly by the histamine released by the mast cells).
Let us follow further the story of the battle of the immune system with the allergen.
Allergens are continuously penetrating your body and consequently mast cells will continuously be stimulated to fire histamine trying to make the environment unfriendly for the allergen. At the same time, T helper lymphocytes will call to arms another cell, to help fight the enemy. This cell is the eosinophil. Eosinophils are normally found in the blood but when they are signalled by the Th cells that their help is needed, they cross the blood vessel wall and enter into the organ where the allergic conflict is taking place. Once they get there, the eosinophils start firing the highly aggressive substances which are stored in granules inside them. If this would be an attack on a true aggressor, such as a parasite, intervention of the eosinophils would be deadly for the enemy and would end the conflict. However, in allergy the immune system is fighting with a false enemy, a ghost, and therefore the substances released by eosinophils rather than being helpful, cause a lot of damage of the tissues. These substances are particularly aggressive for the nerves. Consequently, the nerves (which are already made irritable by the histamine released from the mast cells) become very, very twitchy and reactive to the slightest stimulus.
Which are the consequences of the eosinophil action? What will you when this eosinophil attack takes place?
The effects of the eosinophil attack are particularly important for people suffering from allergic rhinitis or asthma in which the intense irritation of the nerves caused by eosinophils leads to an important aggravation of all symptoms and might even bring new features of the disease. Particularly an aggravation of nasal obstruction in rhinitis and breathing difficulties in asthma are correlated with the invasion of eosinophils in the nose or the lungs.
In addition, many people experiencing allergic rhinitis or asthma for a long time, may notice that their symptoms are triggered not only by the allergen but also by factors such as cold, perfumes or other strong odours, tobacco smoke etc or even by making physical effort. Many of you when experiencing this change fear that you might have became allergic to all these factors and wonder if you might have to avoid them for the rest of your life. Neither of this is true. These new triggers of your symptoms are not allergens but irritants for the nerves in the nose or in the airways and anyone (even the healthiest person) would develop symptoms (like nasal blockage, sneezing, rhinorrhoea, coughing or even shortness of breath) if it would be intensively exposed to them. The difference between you and a healthy person is that the eosinophils have made your nerves very sensitive and reactive, and thus, even a short or mild exposure to any of these factors (which would not affect a normal person) causes a very intense irritation of your nerves triggering your symptoms. With a correct treatment your nerves function can be restored to normal and your reactivity to irritants vanish.