The extrinsic allergic asthmaThere is talk of extrinsic asthma or allergic when symptoms appear as a result of contact between the organism and environmental elements, such as pollen, mites, fungi, etc.., through inhalation, ingestion or skin contact.
In these cases , is the person's immune system which reacts in an exaggerated, as if it were dangerous, to what actually constitutes no real threat. This overreaction causes the production of a large number of antibodies, immune system cells that try to eliminate the foreign substance molecules. These antibodies cause the chain activation of other cells in this system and the release of mediators of inflamción, such as histamine, in what is called "inflammatory cascade". These processes are responsible for the mucus in the bronchi are inflamed and smooth muscle to contract, thus hindering the passage of air.
Often asthma is also accompanied by allergic rhinitis and conjunctivitis , which would be the consequence of similar processes previous action of substances such as histamine into the nasal mucosa and conjunctiva.
Intrinsic AsthmaHis name is because you can not associate the symptoms with the presence of any external element, or more exactly, immune sensitization to any specific substance.
At times, it has been suggested that this type of asthma appropriate, Actually, those cases where you can not identify the item before which the body reacts .
It is postulated that the origin of this type of asthma is the presence of high or hyper "sensitivity" of the bronchi , so that react a number of different nonspecific stimuli such as strong odors, cold, dry air, excessive moisture, physical exercise, strong emotions, and so on. This excessive bronchial hyperreactivity would result in an excess of sensitivity of nerve receptors in the bronchial mucosa that result from the contraction or spasm of smooth muscle fairly easily.
Through skin reactivity tests (observing the reaction of the skin against contact with a number potential allergens) and bronchial provocation tests (measuring the extent to which declines in lung function after inhaling a bronchoconstrictor substance) can know the type of asthma that presents a person (allergic or intrinsic), and the degree of bronchial hyperreactivity.
Frequently, both types of asthma occur together . Thus, although initially a person can manifest asthma only in the presence of pollen, for example, progressively and as a result of repeated inflammation of the bronchial mucosa, can produce a sensitization of the bronchi to other nonspecific stimuli such as above (cold, dry air, exercise, strong odors, etc.)..