Asthma: When Inhaled Steroids Aren't Enough
According to the recently released NHBL Institute guidelines, all patients with asthma that have symptoms more than twice a week should be placed on maintenance anti-inflammatory therapy, such as inhaled steroids, nedocromil, or leukotriene modifiers.
Even in fairly severe asthmatics, inhaled steroids can control symptoms, improve lung function, and lessen the need for systemic steroids. In those patients who are taking high doses of inhaled steroids and still require frequent systemic steroids, several points should be considered.
Likely the most common reasons for lack of response to inhaled steroids is inadequate inhaler technique and poor compliance. One study revealed that only 15% of patients used their inhalers correctly. In addition, because of the lag time in the onset of effect of inhaled steroids, patients tend to not associate the use of these drugs with their effect - thus they become non-compliant. Patient education can often rectify this.
Other common exacerbating factors are chronic sinusitis and gastroesophageal reflux disease. These disorders are often occult, and require either empiric therapy (e.g., antibiotics, proton-pump inhibitors) or diagnostic testing (e.g., sinus CT, 24-hour pH monitoring with esophageal manometry).
Much less commonly, Allergic bronchopulmonary aspergillosis (ABPA) is a consideration in the systemic steroid requiring asthmatic. This complex inflammatory disease is typified by abnormal chest films and central bronchiectasis. A negative skin-prick test to aspergillus mold extract or a normal total IgE during a disease flare make this diagnosis very unlikely.
Occasionally, a patient with asthma will have cough that is especially resistant to therapy. The cough could be due to an Angiotensin-Converting Enzyme inhibitor (ACE-inhibitor) given for hypertension. This may be overlooked because this adverse effect may not manifest itself for months after the drug is started.
Finally, upper airway disorders should be considered in the difficult to control asthmatic. An inorganic disorder called vocal cord dysfunction, has come to be recognized as a possibility in these patients. Although this is usually a diagnosis of exclusion, the involuntary closure of the vocal cords on inspiration can occasionally be seen on direct visualization of the larynx during an attack. Interestingly, many of the reported cases involve health care workers. Unfortunately, it has been seen in patients with severe sequelae of chronic oral steroid use due to an incorrect diagnosis of severe asthma.
In summary, the great majority of asthmatic patients can be well controlled with inhaled steroids and beta-agonists (short- and long-acting forms). In those resistant patients, poor compliance and other underlying disorders should be taken into consideration.