New asthma guidelines emphasize control, regular monitoring
ABSTRACTUpdated asthma care guidelines have recently been released. This review will focus on several elements in the third Expert Panel Report (EPR3) guidelines that reflect substantial differences from recommendations of the second EPR (EPR2) guidelines, issued in 1997 and updated in 2002. A major difference is the emphasis on asthma control. Asthma control can be assessed serially by the use of validated instruments. The goal of asthma therapy is to achieve asthma control by reducing current impairment and future risk. Recommendations for asthma pharmacotherapy have also been revised since the release of the updated EPR2 guidelines. The revisions in asthma management proposed in these guidelines offer the potential for improved asthma care outcomes in the United States.
KEY POINTS
- The EPR3 recommends that management decisions be based initially on asthma severity, and subsequently on asthma control as assessed serially by validated tests.
- Omalizumab, a monoclonal antibody against immunoglobulin E, is the only adjunctive therapy to demonstrate efficacy when added to high-dose inhaled corticosteroids plus long-acting beta agonists in patients with severe, persistent, allergic asthma.
- The EPR3 guidelines recommend consideration of allergen immunotherapy for patients with mild or moderate persistent allergic asthma.
Many patients need skin testing
Allergen immunotherapy may be considered for patients with asthma for whom a clear relationship exists between symptoms and exposure to an allergen to which the patient is sensitive.53 Because it is often not possible to determine whether a patient is sensitive to a perennial indoor allergen (eg, dust mite) on the basis of the medical history alone,55 many patients with asthma benefit from immediate hypersensitivity skin testing to objectively assess or rule out allergy to common inhalants. In certain situations, in vitro testing may be performed, but skin testing has a higher negative predictive value and is recommended as a better screening test.56
Benefits of allergen immunotherapy
Numerous randomized, double-blind, placebo-controlled trials have shown that allergen immunotherapy is associated with benefit for reducing symptoms and medication reliance.57–63
A meta-analysis of 75 randomized, placebo-controlled studies confirmed the effectiveness of immunotherapy in asthma, with a significant reduction in asthma symptoms and medication use and with improvement in bronchial hyperreactivity.64 This meta-analysis included 36 trials of dust mite allergen, 20 of pollen, and 10 of animal dander. Immunotherapy is efficacious for pollen, mold, dust mite, cockroach, and animal allergens; however, its effectiveness is more established for dust mite, animal dander, and pollen allergens, as fewer studies have been published demonstrating efficacy using mold and cockroach allergens.53
In addition, several studies have found that children with allergic rhinitis who receive allergen immunotherapy are significantly less likely to develop asthma.65–67 Immunotherapy has also been associated with a statistically significant reduction in future sensitization to other aeroallergens.68,69
Risk of systemic reaction from allergen immunotherapy
The decision to begin allergen immunotherapy should be individualized on the basis of symptom severity, relative benefit compared with drug therapy, and whether comorbid conditions such as cardiovascular disease or beta-blocker exposure are present. These comorbid conditions are associated with heightened risk of (more serious) anaphylaxis—the major hazard of allergen immunotherapy.70 Systemic reactions during allergen immunotherapy occur at a rate of approximately 3 to 5 per 1,000 injections; for this reason, allergen immunotherapy should only be administered in a medical facility where personnel, supplies, and equipment are available to treat anaphylaxis.5
