Review

Diagnosis and management of asthma in children

Abstract

Asthma is the the most common chronic respiratory condition of childhood worldwide, with around 14% of children and young people affected. Despite the high prevalence, paediatric asthma outcomes are inadequate, and there are several avoidable deaths each year. Characteristic asthma features include wheeze, shortness of breath and cough, which are typically triggered by a number of possible stimuli. There are several diagnostic challenges, and as a result, both overdiagnosis and underdiagnosis of paediatric asthma remain problematic.

Effective asthma management involves a holistic approach addressing both pharmacological and non-pharmacological management, as well as education and self-management aspects. Working in partnership with children and families is key in promoting good outcomes. Education on how to take treatment effectively, trigger avoidance, modifiable risk factors and actions to take during acute attacks via personalised asthma action plans is essential.

This review aimed to provide an overview of good clinical practice in the diagnosis and management of paediatric asthma. We discuss the current diagnostic challenges and predictors of life-threatening attacks. Additionally, we outline the similarities and differences in global paediatric asthma guidelines and highlight potential future developments in care. It is hoped that this review will be useful for healthcare providers working in a range of child health settings.

Key messages

  • Paediatric asthma outcomes are poor and many deaths are preventable.

  • Diagnosing asthma in childhood can be challenging, and the diagnosis should be reviewed during follow-up to ensure it is correct.

  • Asthma attacks should be viewed as never events. Postattack reviews are essential to optimise maintenance therapy and prevent future attacks.

  • Education is key to improving asthma outcomes.

  • Personalised asthma action plans are essential, and a significant number of children with asthma do not have one.

Introduction

Asthma is a chronic respiratory disease characterised by episodes of wheeze, cough, and shortness of breath. Around 14% of children worldwide have a diagnosis of asthma, making it the most common chronic respiratory disease of childhood.1

Poor asthma control is associated with a number of negative effects on children and families. For example, they are more likely to be absent from school, have additional educational needs and have lower educational attainment.2 Caregivers also experience missed work days and financial challenges as a result.3 Some children will experience severe symptoms and life-threatening attacks.4

Taking the UK as an example, paediatric asthma outcomes are poor overall with considerable associated morbidity and high rates of emergency hospital admissions, and most pertinently, there are several preventable deaths each year.5 Alarmingly, the National Review of Asthma Deaths (NRAD) found that in almost all paediatric cases, there were a number of significant avoidable contributing factors and that these deaths may have been preventable.6

There are several factors that make the diagnosis and management of asthma in children challenging. The aim of this review was to explore these issues and highlight good clinical practice in the diagnosis and management of paediatric asthma.

Presentation of asthma

Children with asthma typically present with a symptom triad of wheeze, shortness of breath and cough. However, ‘asthma’ is an umbrella term used to describe this collection of symptoms and, when present, should prompt practitioners to ask, ‘What type of asthma is this?’ There are a number of asthma subtypes that present and respond to treatment differently. Identification of the features of asthma and modifiable or treatable traits should only be the start of the diagnostic journey.7 Asthma symptoms are normally intermittent in nature and may not be present at the time of clinical review, making the diagnosis challenging in some cases.8 Additionally, disease phenotypes are not fixed and may evolve over time, necessitating ongoing review of symptoms and treatment.9

Wheeze is a key feature of asthma and, if not present, a diagnosis of asthma in a child is unlikely. Wheeze is an expiratory high-pitched whistle that occurs as a result of inflammation and narrowing of the small airways. Parental understanding of wheeze varies, and clarifying what is meant when it is reported is key in making an accurate diagnosis.10

The prevalence of ‘preschool wheeze’ is an additional challenge when diagnosing asthma in young children. In the first few years of life, many children will experience wheeze, but not all will go on to develop true asthma. The diagnosis of asthma should therefore be reviewed routinely to identify true asthma and alter treatment where necessary.11 Favourable response to an appropriate trial of asthma treatment is an important confirmatory piece of diagnostic evidence.

Clinical examination may be normal in children and adolescents with asthma if they present during asymptomatic periods. During acute attacks, use of accessory muscles of respiration and widespread wheeze may be present.12 Chest hyperinflation may be identified in acute and chronic disease settings.

Asthma triggers

Asthma attacks commonly occur following exposure to one or several triggers. Viral respiratory infections remain the leading cause,13 but there are a number of other known triggers (box 1), including aeroallergens, secondhand smoke exposure, or changes in ambient air temperature or humidity. Identification and documentation of specific asthma triggers should be part of routine care. Education on trigger recognition and avoidance is essential.

Box 1

Common asthma triggers

  • Viral respiratory tract infections6

  • Exercise6 59

  • Weather changes in temperature and humidity6 59

  • Domestic pollutants (eg, pests, mould and dust mites)6

  • Environmental pollutants (eg, air pollution)6

  • Secondhand smoke exposure13 59

  • Pets and animals13

  • Strong odours13

  • Anxiety or strong emotions59

  • Drugs (eg, non-steroidal anti-inflammatory drugs and beta blockers)59

  • Gastro-oesophageal reflux59

Risk factors for asthma

There are a number of risk factors that should be explored in the history of children who present with features of asthma. In symptomatic children, a personal or family history of atopic features, including asthma, eczema or rhinitis, supports a diagnosis of asthma. Some additional risk factors are outlined in box 2. Education on modifiable risk factors, for example, exposure to secondhand smoke or air pollution and obesity, should be delivered routinely during consultations and asthma reviews. A range of social determinants that are linked to poverty impact on outcomes and the health of children with asthma.14

Box 2

Asthma risk factors

  • Personal or family history of atopy: eczema, allergic rhinitis or nasal polyposis60

  • Family history of asthma60

  • Exposure to secondhand smoke60

  • Preterm birth21

  • Low birth weight61

  • Obesity62

  • Poor housing quality/mould and dampness6

  • Air pollution63

Paediatric asthma phenotypes

Asthma is a heterogeneous disease in which there are several phenotypes and underlying endotypes. Phenotypes are subtypes of asthma that share clinical characteristics such as symptom triggers, atopic features, disease severity and response to treatment. Endotypes are subtypes of asthma that are characterised by similar underlying biological mechanisms.15

Key endotypes include ‘type 2-high’ and ‘type 2-low’ asthma.16 Identifying asthma phenotypes and endotypes can facilitate targeted treatment based on the pathophysiology occurring in a specific individual.17 For example, allergic or eosinophilic asthma that frequently starts in childhood is type 2-high and is characterised by eosinophilic airway inflammation, raised IgE and fractional exhaled nitric oxide (FeNO) levels.15 Typically, type 2-high asthma responds well to inhaled corticosteroid (ICS) treatment.7 A number of biologic agents can be used in the management of asthma, under specialist supervision, and their use varies on asthma endotypes (table 8).18

Differential diagnoses and diagnostic uncertainty

Misdiagnosis of asthma remains a major problem with rates of both underdiagnosis and overdiagnosis being high.19 Overdiagnosis is problematic as it exposes children to unnecessary side effects of medications and runs the risk of trivialising asthma.7

There are several conditions that may be associated with chronic cough, wheeze and/or shortness of breath in children and therefore present similarly to asthma (table 1). Due to the difficulties with diagnosis, especially in young children where objective testing is not possible, the diagnosis of asthma should be reviewed at each clinical presentation and interaction.

Table 1
|
Asthma differentials and clues in medical history

Diagnosing asthma in children

There is no single ‘gold-standard’ test that can be used to accurately diagnose asthma. In practice, a diagnosis should be made based on characteristic symptom patterns, evidence of variability in airflow limitation in the presence of airway inflammation, likelihood of alternative diagnoses and response to treatment. Getting the diagnosis correct is key for optimal management of paediatric asthma.

Lung function tests can be used to aid the diagnosis of asthma in children over the age of 5 years. Peak expiratory flow (PEF) and spirometry are commonly used to assess airflow obstruction and reversibility. PEF can be used to detect diurnal variation, which is a typical feature of asthma. The Global Initiative for Asthma (GINA) specifically recommends the use of either PEF or spirometry in the diagnosis of asthma in children over 5 years.20 Once a child is old enough to reliably perform lung function testing, it is recommended that this be undertaken if the diagnosis of asthma has not been previously confirmed. In children under 5, lung function testing is rarely practical outside a research setting. This makes diagnosis in this age group additionally challenging.21 Guidelines vary between countries and regions with regard to diagnostic criteria. An overview of the similarities and differences between these guidelines is displayed in table 2. Lung function testing is frequently used to monitor progress of children with asthma as part of their care. Objective testing should be repeated if there is poor response to treatment or diagnostic uncertainty.

Table 2
|
Summary of paediatric asthma national guidelines: focusing on diagnosis

FeNO is used to detect and quantify eosinophilic airway inflammation with levels elevated in those with eosinophilic asthma.22 Once staff are trained, and provided equipment is available, FeNO is a practically useful test that is quick to perform in school-aged children. The exact positioning of FeNO testing varies between guidelines worldwide (table 2). FeNO monitoring may also be useful in titrating dosage of ICS in those with an established diagnosis of asthma.23

Allergy testing (skin prick testing or measurement of specific IgE levels) is not routinely carried out in the diagnostic process; however, it is recommended in a number of clinical guidelines and may identify individual triggers.24–27

There are several aspects that make paediatric asthma diagnosis challenging. Most diagnoses are made in primary care where there is often limited access to objective testing at present. Despite guideline recommendations, objective testing is frequently only available in secondary or tertiary care settings where equipment and trained staff are available. The COVID-19 pandemic has served to exacerbate these issues and increase backlogs. Various solutions have been proposed, including community diagnostic hubs.28 In some healthcare systems, the cost of undergoing objective testing is a cause of health inequalities.

Additionally, the symptom onset for most cases of paediatric asthma occurs before the age of 3 years29 when lung function testing cannot be used to aid diagnosis. In this age group, response to an asthma treatment trial is useful to aid diagnostic decision making and is recommended in a number of national guidelines.27 30–32

Management of asthma in children

The management of asthma is multifactorial, and to optimise disease control, a number of pharmacological, non-pharmacological and self-management aspects need to be considered.

Pharmacological management

The pharmacological management of asthma involves two key components: maintenance and reliever therapies. Maintenance therapies are the mainstay of asthma management, and the treatment aim is that no reliever therapies are required. Use of reliever therapy suggests asthma control is poor.

An overview of maintenance and reliever therapies is outlined in tables 3 and 4, respectively. A stepwise approach to asthma management is encouraged, and pharmacological management varies on age, symptom control and the national guideline used. An overview of management approach in a number of national guidelines is summarised in table 5.

Table 3
|
Maintenance therapies
Table 4
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Reliever therapies
Table 5
|
Summary of paediatric asthma national guidelines: focusing on management
Table 6
|
Biologic agents used in the management of asthma

GINA guidelines recommend dual ICS and short-acting beta-2 agonist (SABA) therapy to children over the age of 5.20 SABA monotherapy was previously the main management starting point; however, compared with combined treatment, SABA monotherapy has been shown to be associated with asthma mortality.33 SABA monotherapy is now only recommended by GINA for use in children aged 5 or less.20 As seen in table 5, GINA recommends symptom-driven ICS use, compared with daily ICS use, as initial therapy in children over 6 years of age. In comparison to daily ICS use, symptom-driven use has demonstrated a similar exacerbation risk and reduces the risk of ICS adverse effects.34

Single maintenance and reliever therapy (SMART) inhalers are combined inhalers offering both maintenance and reliever therapy in those with asthma. These inhalers contain a number of maintenance and reliever therapies in different combinations. The use of these inhalers have been shown to reduce the risk of asthma attacks and emergency department (ED) admissions,35 improve lung function and decrease the need for reliever therapy.36 There is limited evidence in the effectiveness of SMART inhalers in children, but children over 12 years may be prescribed a SMART inhaler, which acts as both a maintenance and reliever therapy, if symptoms are not well controlled.37

There are a number of biologic agents (table 6) that may be used in the management of paediatric asthma. These are endotype-specific, targeted therapies that should be used only under the supervision of specialists. Their availability and cost vary between countries and different healthcare systems. Detailed appraisal of the evidence base for their use is provided in the individual management guidelines and has been recently reviewed.17

Non-pharmacological management

Non-pharmacological aspects of asthma management include providing education on modifiable risk factors and comorbidities to caregivers and conducting annual asthma reviews to assess control and future risk.

Education is key to improving caregiver and child understanding of asthma and its management. Clear information regarding modifiable risk factors, such as smoke exposure, domestic pollutants and obesity, should be given. Short-term educational interventions aimed to improve self-management have been shown to increase medication adherence,38 improve symptom control and reduce mortality.39

All young people with asthma should have asthma reviews at least annually. These reviews should focus on current symptom control and management, previous attacks, triggers, modifiable risk factors and personal asthma action plans (PAAPs). Asthma reviews are opportunities to assess child and caregiver understanding of asthma and provide education, if necessary. Annual asthma reviews are also opportunities to assess inhaler technique (including spacer use) and provide education on this if necessary. Poor inhaler technique is common in young people with asthma40 and associated with poor disease control.41

Taking time to understand the perceptions of young people and their caregivers in relation to their asthma diagnosis and management is important, and exploring such perceptions may enhance engagement during consultations, subsequently improving outcomes for young people.42

Self-management

Self-management aspects of paediatric asthma management include asthma education and PAAPs. PAAPs are written documents that are given to young people and/or caregivers that advise them on day-to-day asthma management and what to do in the event of an attack.43 Action plans should be created with patient/caregiver input, shared with relevant individuals (eg, school teachers) and should be reviewed and updated regularly. PAAPs have been shown to reduce ED attendance and missed school days and to increase caregiver confidence when managing attacks.44 The 2018 Annual Asthma Survey found that over 50% of children with asthma in the UK had no PAAP, and around 20% of caregivers did not seek medical advice during acute asthma attacks, highlighting large gaps in education.45

Diet and exercise are additional important self-management aspects within paediatric asthma care. A number of short-term exercise interventions have demonstrated improvements in lung function and symptom control.46 Healthy eating interventions can help reduce body mass index and improve the quality of life of both young people and their caregivers.47

Withdrawing management/stepping down

Asthma control should be reviewed at every medical contact. When asthma symptoms are well controlled on pharmacological therapy, stopping or stepping down medication should be considered to protect young people from unnecessary adverse effects.

The GINA 2021 guidelines advise that clinicians should consider stepping down asthma management to the lowest effective treatment regimen when good symptom control has been achieved for at least 3 months.20 When stepping down treatment, an individualised risk–benefit approach should be taken with focus on the child’s medical history, including frequency of oral corticosteroid use, frequency of asthma attacks, and previous intensive or high-dependency care admissions.48

When to refer to a specialist

Most paediatric asthma cases are diagnosed in primary care without the input of general paediatricians or paediatric respiratory physicians.6 However, a number of children with asthma may need to be referred to specialists for diagnostic or management input. Common indications for specialist referral include no or poor response to asthma treatments, inconclusive objective testing, poor symptom control with appropriate treatment, frequent oral corticosteroid use or the occurrence of a severe asthma attack.20 27 30 31 49 50 A key element of specialist care is a multidisciplinary team consisting of a number of professionals, including specialist nurses, psychologists, physiologists and pharmacists.

Healthcare professionals must consider any safeguarding implications at all paediatric asthma reviews as part of delivering holistic care. Unexplained or frequent ‘do not attend’ appointments or suspicion of poor medical management at home should be flagged and acted on locally.

Predictors of life-threatening attacks

The following features have been shown to increase the likelihood of future severe attacks, and particular attention should be given to these factors during asthma reviews:

  1. Previous attack. The strongest risk factor for a future asthma attack is a personal history of a previous attack. One large systematic review and meta-analysis found that children with a recent history of ED attendance with an asthma attack were up to 5.8 times more likely to have another ED attendance and up to three times more likely to be admitted to the hospital with a future asthma attack.51

  2. Frequent SABA use and prescription requests. Frequent use of SABA reliever therapy suggests poor control of asthma symptoms. If asthma symptoms are well controlled, no more than two SABA inhalers should be required annually.52 The UK NRAD found that excess SABA prescription and use were prominent in individuals who died of asthma attacks. For those with data available, around 40% had been prescribed 12 or more SABA inhalers in the 12 months before death.6

Postattack review

Asthma attacks should be viewed as never events. It is essential that a postattack review is conducted to review asthma maintenance treatment, as this is likely to be suboptimal. Failure to review patients post attack, and to alter treatment where appropriate, is likely to predispose to future attacks, which could be life-threatening. Management of the current attack should be reviewed to ensure treatment is appropriate and symptoms are resolving. Some individuals may require additional courses of oral corticosteroids to settle symptoms.7

Current NICE quality standards (UK) state that all individuals hospitalised with an asthma attack should receive a follow-up review in primary care within two working days of discharge,49 to review maintenance management and ensure resolution of symptoms. However, the 2018 National Asthma Survey completed in the UK found that 64% of respondents had no primary care follow-up post attack, and most patients were not aware that this was required.45

Salbutamol weaning

Salbutamol weaning plans are commonly used by a number of healthcare organisations following discharge after an asthma attack. These plans direct caregivers to provide regular SABA therapy, often in a reducing regime, in the days following discharge. There have been a number of concerns raised with regard to these plans with some believing that providing regular SABA therapy may potentially mask deterioration and could delay care givers seeking medical advice.53 Healthcare professionals should enquire about salbutamol weaning plans during postattack reviews and urge caregivers to seek medical advice if they have concerns or the effects of SABA are not lasting the 4 hours of duration.

Future developments in care

The management of paediatric asthma is changing over time with, just as two examples, developments in technology and service structure:

  1. Technology. The growing use of technology in asthma care has huge potential to improve clinical outcomes. Smartphone applications can be used to provide medication reminders to users, and this has been shown to increase ICS adherence.54 Applications can also be used to provide educational content to young people and caregivers,55 as well as store PAAPs.56 ‘Smart’ inhalers, not to be confused with SMART inhalers, are devices that can provide audio reminders to users and record when they are used. One paediatric study found that the use of smart inhalers increased treatment adherence to 84%, compared with 30% in the control group.57

  2. Diagnostic hubs. In the UK, regional diagnostic hubs for asthma care have been recommended in NHS England’s Long Term Plan.58 Implementation of diagnostic hubs is hoped to result in earlier and more accurate asthma diagnoses by improving access to objective testing and specialised interpretation. Hubs are designed to improve asthma outcomes by enabling most appropriate treatment initiation and monitoring. There is currently no evidence in the literature of the clinical effects of diagnostic hubs being used in the management of paediatric asthma.

Conclusions

Paediatric asthma outcomes are currently poor and many deaths are preventable. The aim should be to avoid asthma attacks occurring with appropriate maintenance therapy, and they should be viewed as never events. In order to improve outcomes, accurate diagnosis and management are essential. Good asthma care extends beyond providing medication and should include education, as well as supported self-management advice. The use of PAAPs remains limited and a significant number of young people with asthma do not have one. Postattack asthma reviews are a key opportunity to review maintenance medication and current symptom control.