Info about Asthma
Asthma - Inflammation
For the past decade, scientific interest has been focused on inflammation as the body process believed to be the most common cause of asthma. It is a condition that causes increase in blood circulation and migration of injury-fighting white blood cells to the area involved. In the chest, inflammation is often the result of infection, which may be localized to certain areas of the lung or may involve the entire lung. The inflammatory process is not synonymous with infection; inflammation of the lung can also be caused by the presence of airborne irritants such as smoke and chemical vapors and by exposure to pollens and dusts. In each case, the end result of inflammation is to provoke spasm of the bronchial muscles along with increase in secretions and swelling of the bronchial mucous membranes, all of which lead to the signs and symptoms of asthma. Inflammation is a protective process that provides an increase in circulation to the inflamed area, increase in secretions, and movement into the inflamed area of white blood cells that fight disease. Involvement of the bronchi in the inflammatory process is believed to be the most common underlying cause of signs and symptoms of asthma. Inflammation of the smaller bronchial tubes (bronchioles) may accompany the involvement of the bronchi or may develop by itself, as it does in certain viral infections. Symptoms produced by inflammation of the bronchioles are sometimes confused with symptoms of asthma or bronchitis.
Long-standing infection (chronic infection) is a frequent source of tightening of the bronchial muscle-tubes. The chronic infection can be in the lung, but it can be anywhere else in the body. Chronic infection with parasites (worms) has also been known to trigger asthma. More common is the association of chronic sinus infection and bronchospasm.
Long-standing infection of the sinuses is a frequent cause of asthma and one that is often overlooked, particularly when sinus symptoms are mild. Sinuses (paranasal sinuses) are cavities in the bones of the skull that are part of a mechanism the body uses to heat and humidify air on its way to the lungs, and to clear out unwanted materials such as dust. There are four pairs of sinuses, two each of facial (maxillary), forehead (frontal), and midline (ethmoid and sphenoid). Sinuses are not present at birth but develop in the early years. Frontal and sphenoid sinuses are late to develop and are not visible on X rays until about age 5, so sinus infection before that age is unusual.
The sinus cavities are lined with mucous membranes that supply moisture to the inhaled air, and also provide a sticky surface on which inhaled harmful substances can get stuck and be removed. Normally, these cavities exit their fluids through the nose, from which they drain as a nasal discharge. If the nose is stuffy, drainage from the sinuses can be impaired. This can lead to a collection of fluid in the sinuses, which the asthmatic patient recognizes as a feeling of pressure or fullness in the sinuses, or sometimes as a headache or toothache. Such a collection of sinus fluid can become infected.
Preventing outflow from any body cavity always leads to infection. For example, obstruction to the outflow from the urinary bladder leads to bladder and kidney infection (cystitis and nephritis); blockage in the lung causes lung infection (pneumonia); obstruction of the sinuses can cause sinus infection (sinusitis), and this sinus infection can trigger asthma. This is why some people tend to wheeze with head colds. Of course, the goal of treatment for wheezing with colds is to relieve the obstruction in the nose that blocks outflow from the sinuses.
Sinus infection is easy to diagnose: signs and symptoms of sinusitis include headache, fever, cough, nasal congestion, and nasal discharge, especially if it is a yellow or greenish color. Common complaints suggesting sinusitis include pain in the cheek, in the forehead, or in the midline at the top of the head or at the base of the skull; sometimes, pain in these areas may be accompanied by tenderness of touch. A generalized achy, rundown feeling (malaise) often accompanies chronic sinusitis. These physical findings can be confirmed by X ray and related imaging techniques.
One simple technique that is inexpensive, safe, and often helpful in diagnosing sinusitis is called transillumination. In this process, in a completely dark room, a small, bright light is placed into the patient's mouth. Since the sinuses are air-filled cavities, a normal sinus will pass the light through the air-filled spaces, which can then be seen in outline. If any of the sinuses are congested, the light does not pass through, and the diagnosis of sinus congestion is established. This technique, quick and inexpensive, is most helpful for diagnosis in adults and older children. It is most useful to evaluate the sinuses of the face, less useful for sinuses of the forehead and midline.
Treatment of sinus infection is aimed at relieving the obstruction that causes infection. Since part of the blockage is a result of swollen mucous membranes, decongestants are useful by mouth or as nose drops to shrink the mucous membranes. Antibiotics taken by mouth are usually needed for rapid cure. Steroid drugs are the most potent medicines to counter inflammation and serve to decrease swelling, thereby increasing drainage. This medical management is not very expensive, especially if generic drugs are prescribed, nor is it hazardous when used as prescribed.
Unfortunately, the simple diagnosis of sinusitis is often overlooked. Because the symptoms of sinus infection are often very mild, they sometimes do not receive a lot of attention. In children younger than age 6, who may be too young to interpret and identify sinus pain, and at which age the sinuses are still in the stage of development, localizing complaints are less likely to be prominent. Young children may overlook and fail to report nasal blockage and headache. In older children and adults, X rays help with the diagnosis, but some doctors are reluctant to request X rays for symptoms of head cold with coughing. Properly treated, sinusitis as a cause of asthma is easily remedied once the diagnosis has been made. Other causes of asthma are not as easily diagnosed and managed. Asthma that results from activity of the autonomic nervous system is usually harder to identify and manage.