While easily appreciated, asthma symptoms are but the tip of the iceberg in terms of inflammation in the lungs. The first step in treatment is to control the environment, i.e., try to reduce exposure to irritants, such as cigarette smoke, or triggers, such as pets or dust mites. A good understanding of the medication used, whether to control symptoms or to control the underlying inflammation, is necessary for proper prescribing. Treatment of inflammation5 results in symptom resolution, followed by normalization of spirometry and then bronchial hyperresponsiveness.
Inhaled corticosteroids (ICS) comprise the single best treatment for inflamed airways in asthma. Chronic uncontrolled lung inflammation may lead to lung remodeling with resulting fibrotic changes. Studies from both younger and older pediatric groups show reduction in asthma symptoms, reduction in asthma exacerbations, and improved exercise tolerance in children who regularly use ICS.
The use of ICS does not result in any long-term changes in the airways6 or alterations in the course of the disease. Therefore, doses should be modified to the level needed to control the condition and lung function. Use the dose that is necessary, albeit the lowest needed over time, to control the asthma. Small lungs, because of their inspiratory capacity, are exposed only to a smaller amount of the dose given; this is called “autoscaling.”
ICS should be used on a regular basis if there is evidence of persistent inflammation, such as recurrent symptoms or exacerbations. There is no evidence that intermittent use of ICS for sporadic wheezing has any effect on symptoms. In the short term, there is a statistically significant reduction in body-growth velocity when ICS therapy is started. Extended use in routine doses does not appear to affect long-term growth in most children. Within two to three months, the growth velocity becomes similar to that seen with placebo. The length of time a patient should be using ICS depends on the pattern of symptoms that are manifest. Usually, the patient should attain six months of adequate to complete control before discontinuing the medication. If the symptoms are worse during specific times of the year (winter, for example), continuous use during that time, with discontinuation at other times of the year, may be appropriate. Alternate anti-inflammatory treatment with leukotriene modifiers can also be considered. Patient adherence to treatment plans tends to be poor with asthma, so the clinician should monitor the patient closely.
Tips on asthma-device use
Metered-dose inhalers (MDIs) are subject to dose variability that evens out if the patient uses two puffs to get the desired dose, i.e., two puffs of 125 µg may be more effective than one puff of 250 µg. To check pressurized MDIs, one can remove the canister from the plastic case and shake the canister to determine approximately how much medication remains. Sliding one’s fingers up and down the canister until they are at the level where the medication appears to stop will show how empty the devices are.
Some MDIs have dose counters, but if they do not, the recommendation is to count doses. Check the label to note the number of sprays it contains. Based on number of daily uses, calculate how many days the device will last and record a date several days ahead on a daily calendar. Dry-powder devices have either dose counters or a red line that starts to appear when there are 20 doses left in the device (Turbuhaler). Shaking the dry powder device is not helpful, as the Turbuhaler contains a desiccant for the bronchodilator medication. This substance will be heard even when the device is empty of active medication.
When should you look for another diagnosis?
If you have treated your asthmatic patient with a good dose of the appropriate medications, and asthma control is still inadequate, consider possible causes for the nonresponsiveness (Table 4). Adherence, comorbidities, device technique issues, and environmental issues can each play a role in explaining the lack of response, but remember to affirm your diagnosis when faced with this dilemma.
Asthma is the most common chronic childhood condition. But not all that wheezes is asthma. Try to make a diagnosis with objective measurements of airflow. Remember that treatment of the upper airway is needed to adequately control the lower airway. It’s important to reconsider the diagnosis when the presentation is atypical or response to therapy is incomplete. A timely referral for appropriate diagnostics or to a practitioner with special interest in these conditions, can clarify many of these issues. Treatment of asthma should allow the child to live a normal life with minimal symptoms and infrequent exacerbations.
Dr. Kaplan is a family physician who specializes in respiratory disease. He practices in Richmond Hill, Ontario, where he is chairperson of the Family Physician Airways Group of Canada.
1. Mannino DM, Homa DM, Pertowski CA, et al. Surveillance for Asthma — United States, 1960-1995. MMWR. 1998;47(SS-1):1-27.
2. National Asthma Education and Prevention Program. Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma. Bethesda, Md.: National Institutes of Health; 1997. Publication No. 97-4051.
3. Martinez FD, Wright AL, Taussig LM, et al. Asthma and wheezing in the first six years of life. N Engl J Med. 1995;332:133-138.
4. Oswald H, Phelan PD, Lanigan A, et al. Childhood asthma and lung function in mid-adult life. Pediatr Pulmonol. 1997;23:14-20.
5. National Asthma Education and Prevention Program. Highlights of the Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma. Bethesda, Md.: National Institutes of Health; May 1997. NIH Publication No. 97-4051A.
6. Baxter-Jones AD, Helms PJ. Early introduction of inhaled steroids in wheezing children presenting in primary care. Clin Exp Allergy. 2000;30: 1618-1626.