Asthma By Lisa Glickstein, Ph.D, Triplet Mom Originally printed in February 2005 Asthma is increasing in frequency, not only among children, but among adults as well. Asthma is commonly noted between ages two and three in children, usually following a lower respiratory infection. In adults, asthma onset may be associated with either respiratory infection or allergies. In the past, many adults and children with mild, intermittent asthma were probably not diagnosed. Nonetheless, increase in diagnosis doesn't explain the whole story of the increase in asthma. Doctors and scientists are not certain what has triggered the explosion in allergies, and asthma in a subset of allergic patients. Luckily, treatment for asthma has come a long way in the past thirty years - so that we can all breathe a little easier! What is asthma? How is it different from bronchitis, bronchiolitis (croup), and pneumonia? Asthma is a combination of airway inflammation (white blood cell infiltration) and edema (swelling), airway spasm, and excess mucus production. These produce the symptoms of shortness of breath, episodic cough, and chest tightness characteristic of this condition. Bronchitis and bronchiolitis are acute (short-term) inflammatory syndromes of the large and small airways of the lungs, respectively, due to viral or bacterial infection. In these conditions, while the inflammation is similar to that seen in asthma, it is directly caused by the immune response to the invading germ and the germs themselves, and thus it goes away once the infection is cured. Pneumonia is fluid (rather than mucus) in the air sacs and airways, similarly caused by infection (or rarely by inhalation of a foreign object or substance). Because of the accumulation of white blood cells in the lungs during infection, any of these conditions can trigger the onset of asthma in a susceptible child or adult. What is happening during an asthma episode? Whether triggered by an allergen, a virus, or bacteria, asthma begins with the white blood cells lining the lungs. When these cells are turned on by one of their triggers, they produce chemical compounds that act on the muscle cells of the airways, causing spasm, as well as recruiting other white blood cells to exit the bloodstream and enter the lung lining. Over time, the cells that make mucus are also activated. The more episodes of untreated asthma, the more likely that future episodes will be more frequent and more severe, as the cells and their chemical messengers continue to increase. How is asthma treated? Asthma is treated with a two-pronged approach - using rescue medications, and control medications. Patients with moderate to severe asthma may use a peak flow meter to measure their breathing capacity to monitor how well their medications are working. To use a peak flow meter, you just blow into a tube as hard as possible, and read how far your breath was able to push the meter. Rescue medications give quick emergency relief from the airway spasm. They do not have any effect on the white blood cells, their messengers, or mucus. Control medications, in contrast, will not help relieve spasms and cannot treat an asthma episode. However, control medications, taken as directed usually over long periods of time, will kill and subdue the white blood cells, making future episodes less frequent and less severe. Either type of medication may be given orally or in inhaled form. The most common rescue medications are albuterol (Proventil; usually inhaled), and oral steroids. Oral steroids take one to three days to act, and they are usually given as a ten day course to stabilize a severe asthma episode. It is important to keep your albuterol inhaler with you if you have frequent asthma episodes, especially moderate to severe asthma. You should also keep a log of how frequently you need your rescue medication. If you need rescue medication more than twice a week, your doctor will probably want to discuss starting or changing your control medication. There are many types of control medications. These include Singulair, an anti-allergy medication (given orally), cromolyn sodium (inhaled), and steroids (inhaled; Pulmicort, Flovent). There are also specially formulated combination medications. Each has a different mechanism of action on white blood cells. The weakest is cromolyn, which stabilizes the white blood cell first triggered in asthma from releasing its contents. The strongest are steroids, which kill white blood cells and also inhibit the chemical transmitters from working. The newest addition is Singulair, which blocks one of the most important chemical transmitter families released during allergic reactions. Cromolyn is not prescribed as commonly as it once was, as recent studies have shown that inhaled steroids, or inhaled steroids with Singulair given during the allergy season to allergic patients, gave greater relief and less use of rescue medications. Does it matter whether the meds are given orally or inhaled? Using a nebulizer or a spacer? Some medications can only be given in one form. Others have more side effects if given orally rather than inhaled. For example, oral steroids are very potent and can reduce your ability to fight off infections, and stunt growth in children. Inhaled steroids, in contrast, are much more benign. Oral steroids are often given during an acute episode of severe asthma (or bronchitis or bronchiolitis). Then these are tapered off while an inhaled remedy is begun for long term control. Nebulizers, which mix liquid medication and sterile water into an inhalable mist, were formerly the most common method to administer the inhaled medications to children. However, they are cumbersome, require electricity, and can take ten minutes or much longer to administer a required dose. Spacers, basically a small chamber with a mask (for children) or breathing tube (for adults) on one end, and a place to put the metered-dose inhaler on the other, are becoming more common. The "puff" is delivered into the chamber, where it is contained for breathing over 5-7 breaths (for children), or a long, deep breath (for adults). They allow even young children to take a full dose of up to four puffs in 2-4 minutes. They may become more common, based on a recent study that found they were more efficient at dosing children than nebulizers. What is the prognosis for asthma? Mild asthma, in adults or children, can go away after months or years. Children with a history of asthma are more likely to develop asthma again as adults, however. Moderate to severe asthma is usually a lifelong condition. If controlled properly with medication, it does not prevent leading an active, long life. Many athletes have asthma, for example. Children with peanut allergy who also have asthma, especially severe asthma, are at the highest risk of going into anaphylactic shock if they have an exposure to peanuts. These patients need to be carefully monitored and both their exposure and control medications optimized accordingly. What kind of doctor can diagnose and treat asthma? Mild asthma can be diagnosed and treated by your pediatrician or primary care physician. If the asthma is triggered by allergies, a consultation and possibly treatment by an allergist may be beneficial. There is some evidence that allergy shots can reduce seasonal allergies, and in combination with Singulair, can reduce allergy symptoms and asthma in appropriately treated patients. The goal for all patients is the best control of asthma symptoms, using the least amount of medication with the fewest side effects. For more information, I suggest the American Academy of Allergy, Asthma, and Immunology (http://www.aaaai.org/patients.stm).