Asthma, particularly severe asthma, is strongly associated with development of chronic obstructive pulmonary disease (COPD). Those with asthma, especially if it is poorly controlled, are at increased risk for radiocontrast reactions.Cavities occur more often in people with asthma. This may be related to the effect of beta 2 agonists decreasing saliva. These medications may also increase the risk of dental erosions. Causes
Asthma is caused by a combination of complex and incompletely understood environmental and genetic interactions. These influence both its severity and its responsiveness to treatment. It is believed that the recent increased rates of asthma are due to changing epigenetics (heritable factors other than those related to the DNA sequence) and a changing living environment. Asthma that starts before the age of 12 years old is more likely due to genetic influence, while onset after age 12 is more likely due to environmental influence. Environmental
Many environmental factors have been associated with asthmas development and exacerbation, including, allergens, air pollution, and other environmental chemicals. Smoking during pregnancy and after delivery is associated with a greater risk of asthma-like symptoms. Low air quality from environmental factors such as traffic pollution or high ozone levels has been associated with both asthma development and increased asthma severity. Over half of cases in children in the United States occur in areas when air quality is below the EPA standards. Low air quality is more common in low-income and minority communities.Exposure to indoor volatile organic compounds may be a trigger for asthma; formaldehyde exposure, for example, has a positive association.
Anti-leukotriene agents may be effective alone for adolescents and adults, however there is no clear research suggesting which people with asthma would benefit from anti-leukotriene receptor alone. In those under five years of age, anti-leukotriene agents were the preferred add-on therapy after inhaled corticosteroids. A 2013 Cochrane systematic review concluded that anti-leukotriene agents appear to be of little benefit when added to inhaled steroids for treating children. A similar class of drugs, 5-LOX inhibitors, may be used as an alternative in the chronic treatment of mild to moderate asthma among older children and adults. As of 2013 there is one medication in this family known as zileuton. Mast cell stabilizers (such as cromolyn sodium) are safe alternatives to corticosteroids but not preferred because they have to be administered frequently. Oral Theophyllines are sometimes used for controlling chronic asthma, but their used is minimized because of their side effects. Omalizumab, a monoclonal Antibody Against IgE, is a novel way to lessen exacerbations by lessening the levels of circulating IgE that play a significant role at allergic asthma. Anticholinergic medications such as ipratropium bromide have not been shown to be beneficial for treating chronic asthma in children over 2 years old, but is not suggested for routine treatment of chronic asthma in adults. There is no strong evidence to recommend chloroquine medication as a replacement for taking corticosteroids by mouth (for those who are not able to tolerate inhaled steroids).