Clinical Asthma

Theory and Practice

Jonathan Bernstein, Mark Levy, Jonathan Bernstein, Mark Levy

• Publisher: CRC Press
• Year: 2014
• ISBN:
  9780429584862
• Edition: 1
• Topic: Medicina
• Subtopic: Teoría, práctica y referencia médicas

Enormous progress in asthma research has been made in the past 50 years, including a greater understanding of its complex pathogenesis and new and more effective therapies. Consequently, the scientific literature has grown vast and can be difficult to integrate. With contributions from a distinguished panel of world-renowned authors, Clinical Asthm

Section V

Asthma Management and Treatments

17 Management of Pediatric Asthma

Leonard B. Bacharier

CONTENTS

Case Presentation

Goals of Asthma Management in Preschool- and School-Age Children

Heterogeneity of Early Childhood Wheezing and Asthma

Stepwise Approach to Asthma Care

Management of Intermittent Disease (Step 1 Care)

Episodic Controller Therapy

Daily Controller Therapy

Management of Persistent Asthma (Step 2 Care)

Daily ICS Therapy

Daily LTRA Therapy

Approaches for Children Not Well Controlled with Step 2 (and Above) Therapy

Step 3 Care and Above

Temporary Step-Up in Anticipation of Exposure to Predictable Triggers

Immunotherapy

Management of Severe Asthma in Children

Omalizumab

Management of Asthma Exacerbations

Quick Reliever Medications

Beta₂-Adrenergic Agonists

Anticholinergic Agents

Systemic Corticosteroids

Monitoring and Reassessment

Step-Down Therapy

Step-Down to As-Needed Administration of ICS in Children with Mild Asthma

Conclusions

References

CASE PRESENTATION

A 4-year-old boy presents for an evaluation of recurrent episodes of cough and wheezing since 1 year of age. His initial episode, at age 3 months, was in the setting of a viral illness that was characterized by coryza, low-grade fever, and wheezing. For the past 2 years, he experienced cough and wheeze with nearly all upper respiratory tract infections. Over the past year, his mother has noticed him coughing and wheezing while playing soccer in addition to similar symptoms during upper respiratory tract infections. He awakens due to cough or wheeze approximately twice monthly. Albuterol consistently provides him with prompt, albeit transient, symptom relief. Oral corticosteroids have been prescribed twice yearly for the most significant episodes. No emergency department visits or hospitalizations have been required.

His past medical history is notable for an itchy rash over the antecubital and popliteal fossae since 1 year of age, which improved with topical corticosteroids. He has never had pneumonia or croup. His only current medication is albuterol by nebulization as needed. His environment contains a cat and wall-to-wall carpeting throughout the home. The family history is notable for asthma in the father and allergic rhinitis in the mother.

On physical examination, he is alert, interactive, and not distressed. His weight is at the 45th percentile and his height is at the 40th percentile. His heart rate is 100/ min and his respiratory rate is 16/min. He has infraorbital shiners, edematous and pale nasal turbinates, no tonsillar enlargement, and his chest examination is clear without adventitious lung sounds or evidence of increased work of breathing. His skin examination discloses erythematous papules and excoriation in the antecubital fossae bilaterally. His chest radiograph is normal without infiltrates or hyperinflation. His parents wonder what can be done to prevent him from experiencing further episodes of cough and wheeze.

GOALS OF ASTHMA MANAGEMENT IN PRESCHOOL- AND SCHOOL-AGE CHILDREN

The principles of asthma management in preschool- and school-age children have evolved substantially over the past two decades to the current approach that is guided by the goals of the attainment and maintenance of asthma control (see Chapter 16). In contrast to asthma severity, which defines the intrinsic intensity of asthma as assessed without the use of a controller therapy, asthma control reflects the degree to which the signs and symptoms of asthma are minimized. Thus, successful asthma management achieves multiple goals, including (1) the minimization of day-today asthma-related symptomatology (i.e., a reduction in the current impairment domain of asthma); (2) the reduction or elimination of asthma exacerbations; (3) the minimization of treatment-related side effects; and (4) ideally, the prevention of impaired lung growth and progressive decline in lung function (i.e., a reduction in the future risk domain of asthma).

Preschool-age children often exhibit asthma that is more exacerbation prone than impairment dominant, while schoolage children begin to demonstrate elements of both impairment and risk. The recognition of these different phenotypes and patterns of asthma expression has directed the research examining different treatment strategies in these two age groups, with exacerbation prevention and disease modification being the major focuses in preschool-age children while exacerbation prevention has been coupled with impairment reduction and interventions to prevent declines in lung function among school-age children.

HETEROGENEITY OF EARLY CHILDHOOD WHEEZING AND ASTHMA

Recurrent wheezing in the preschool-age group is a highly heterogeneous disorder, with multiple disease phenotypes based on the age of onset, age and likelihood of remission, concomitant risk factors (especially atopy), and triggering factors (such as viral infections). These multiple different phenotypic expressions of early childhood asthma are likely due to different underlying immunopathophysiological mechanisms, which may confer differential responses to therapeutic strategies. The heterogeneity of early childhood wheezing and asthma complicates the interpretation of much of the early research done in this population, as most of the early studies enrolled very heterogeneous populations of subjects rather than specific wheezing phenotypes. Fortunately, several recent studies have begun to focus on more well-defined and homogeneous populations, providing evidence to guide decision making in this challenging age group.

STEPWISE APPROACH TO ASTHMA CARE

Over the past decade, several asthma guidelines have been developed that provide carefully developed treatment recommendations for children with asthma, including the National Asthma Education and Prevention Program (NAEPP),¹ the Global Initiative for Asthma (GINA),² and the European Respiratory Society (ERS) task force.³ All of these guidelines have proposed algorithms for the pharmacological management of asthma using stepwise approaches, with the steps of care being aligned with the levels of both the asthma severity and control. While the guidelines differ in terms of the number of steps of care and the order of preferences of treatments within each step,⁴ there is a consensus that the achievement of asthma control is the major goal of therapy and that an individualized approach for each child is necessary based on the level of control achieved.

MANAGEMENT OF INTERMITTENT DISEASE (STEP 1 CARE)

According to the NAEPP guidelines, children with intermittent asthma under the age of 12 should receive Step 1 care (Figure 17.1), which includes as-needed use of a short-acting beta-agonist (SABA). The phenotype of intermittent asthma is most apparent in the preschool population, where it has been referred to using various terminology, including severe intermittent asthma and episodic viral wheeze. This phenotype exemplifies an exacerbation-dominant disease with minimal to no intercurrent symptomatology. However, given the substantial morbidity experienced during these episodes, therapeutic strategies aiming to prevent or attenuate episode severity, ranging from daily preventative therapy to episodic therapy, have been studied. In recognition of this symptom pattern, and since publication of the NAEPP guidelines in 2007, several studies have clarified and broadened the treatment possibilities for young children with intermittent/episodic disease, including the episodic use of controller medications at episode onset to attenuate symptom progression as well as the examination of daily controller therapy intended to prevent exacerbations.

EPISODIC CONTROLLER THERAPY

The intermittent and episodic nature of this condition has led parents, physicians, and investigators to consider the potential efficacy of the intermittent use of controller therapies just during periods of increased asthma symptomatology, such as viral respiratory tract infections. The use of high-dose inhaled corticosteroid (ICS) therapy (fluticasone propionate 750 mcg twice daily) in 1- to 6-year-old children started at the early signs of a developing respiratory tract illness reduced the risk of oral corticosteroid use by approximately 50%, but was associated with statistically significant reductions in both height and weight gain.⁵ In contrast, two studies examining budesonide used intermittently (either 1 mg twice daily for 7 days at the earliest signs of a respiratory tract illness or 400 mcg daily beginning 3 days after the onset of respiratory tract symptoms) did not demonstrate a reduction in exacerbations requiring oral corticosteroids,^6,7 but it did result in modest reductions in symptomatology during illnesses.⁶ The episodic use of montelukast at the early signs of respiratory tract illnesses also produced modest reductions in symptomatology without reducing the need for systemic corticosteroids.⁶

FIGURE 17.1 NAEPP stepwise approach for the long-term management of asthma in children aged 0–4 years (upper panel) and 5–11 years (lower panel). (Modified from National Asthma Education and Prevention Program. Expert Panel Report III: Guidelines for the diagnosis and management of asthma. Bethesda, MD: US Department of Health and Human Services; 2007.)

DAITY CONTROTTER THERAPY

Given the severity of the episodes that are experienced by many children with intermittent disease, studies of daily controller therapy aimed at episode prevention have also been conducted. Daily treatment with low-dose ICS (fluticasone propion...