Abstract and Introduction
Abstract
Purpose of review: The new guidelines for assessment of asthma control emphasize two domains: impairment and risk. Exacerbations of asthma are an important component of risk but have not received as much attention as the day-to-day symptoms that make up impairment. The purpose of this review is to report what has recently been learned about exacerbations.
Recent findings: Exacerbations occur in the context of both controlled and uncontrolled asthma. Exacerbations are a strong independent risk factor of further exacerbations. This suggests that unrecognized factors may be involved in susceptibility to exacerbations in addition to more commonly recognized triggers such as viruses, allergens, and poorly controlled asthma. Such factors may be the result of genetic variation. Recent evidence now shows a residual effect on lung function from an exacerbation event. There are no current specific intervention measures to prevent exacerbations but attention to management practices continues to look at the role of the emergency department in improving care.
Summary: The presence of exacerbations is considered a risk factor of the likelihood of further exacerbations and requires assessment of the triggers identified with history of exacerbations, host factors, atopic disposition, exposure to allergens, adherence to prescribed medications, and preventive measures to reduce future risk of such an event.
Introduction
Exacerbations are a component of asthma that has significant impact on both the child and the child's family. Exacerbations are often the initial event in the recognition of this disease and subsequently represent the majority of acute care events for children.
Current assessment of asthma compartmentalizes components of asthma to assess the level and effectiveness of control measures. These guidelines use the term impairment to assess the symptoms and impact of asthma on the child's day-to-day life. Risk acknowledges that a previous exacerbation event puts the child at risk for recurrence and requires the physician to take this into consideration when planning prevention and future management. It is only recently that the presence of an exacerbation has been given equality with impairment in assessing the level of control. However, two domains are not necessarily concordant. Patients may be well controlled in the impairment domain and be receiving optimal medications, yet still experience a severe exacerbation. Current interest is reflected in the many recent publications examining exacerbations from various points of view, including a consensus for definition, factors associated with exacerbations, evidence that the exacerbation event itself is an independent predictor of future events, efforts to preempt the event, and continued interest in management through emergency department (ED) intervention.