SciELO - Scientific Electronic Library Online

 
vol.111 número8Asthma in South African children: Guidelines, obstacles and solutionsManagement of asthma exacerbations in children índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Artigo

Indicadores

Links relacionados

  • Em processo de indexaçãoCitado por Google
  • Em processo de indexaçãoSimilares em Google

Compartilhar


SAMJ: South African Medical Journal

versão On-line ISSN 2078-5135
versão impressa ISSN 0256-9574

SAMJ, S. Afr. med. j. vol.111 no.8 Pretoria Ago. 2021

http://dx.doi.org/10.7196/samj.2021.v111i5.15851 

CME

 

Childhood asthma: A best-practice strategy for diagnosis and assessment of control in South Africa

 

 

A van NiekerkI; D A WhiteII; P GoussardIII; S M RisengaIV

IMB ChB, MMed (Paed); Department of Paediatrics and Child Health, School of Medicine, Faculty of Health Sciences, University of Pretoria, and Steve Biko Academic Hospital, Pretoria, South Africa
IIMB BCh, FC Paed (SA), MMed (Paed), Dip Allerg (SA), Cert Pulmonology (SA) Paed; Department of Paediatrics and Child Health, Faculty of Health Sciences, University of the Witwatersrand, and Charlotte Maxeke Johannesburg Academic Hospital, South Africa
IIIPhD; Department of Paediatrics and Child Health, Faculty of Health Sciences, Stellenbosch University, and Tygerberg Hospital, Cape Town, South Africa
IVBSc, MB ChB, MMed (Paed), DCH, Dip Allerg (SA), Cert Pulmonology (SA) Paed; Department of Paediatrics and Child Health, Faculty of Health Sciences, University of Limpopo, and Pietersburg Hospital, South Africa

Correspondence

 

 


ABSTRACT

The South African (SA) Childhood Asthma Working Group of the Allergy Society of SA (ALLSA) advises on best-practice strategy for childhood asthma management. The strategy is in accordance with current evidence and consensus. The aim of this review is to inform on a best-practice strategy for asthma diagnosis and the assessment of asthma control in SA children who attend public and private healthcare services. The diagnosis of asthma is more difficult in preschool-aged than school-aged children. This review proposes a four-step diagnostic approach in both groups, with an added obligation to objectively measure variable expiratory airflow limitation in school-aged children. Asthma control refers to the degree to which the effects of asthma can be seen in patients, or to which these have been reduced by treatment. After initiation of treatment, it is essential to assess asthma control at regular follow-up visits, and to adjust treatment accordingly. Patient education is key to attaining control.


 

 

Asthma should be diagnosed in children who present with episodes of variable expiratory airflow limitation. An accurate diagnosis relies on the clinical skills of the clinician. The clinical diagnosis should be supported by objective measurements, such as lung function testing, in school-aged children.

The symptoms of asthma may include episodic wheeze (owing to bronchoconstriction), shortness of breath, difficult or laboured breathing, chest tightness and reduced activity with or without cough. The intensity varies over time, and symptoms improve after a correctly administered rapid-acting inhaled bronchodilator.[1] More than one symptom is usually present. An isolated cough is seldom due to asthma. The variation in symptoms may be triggered by factors such as viral airway infections, allergens, irritants, cold air, exercise and sudden emotional changes (e.g. crying or laughing).

The symptoms are not specific to asthma, and other conditions may mimic the disease. Chronic airway inflammation with variable expiratory airflow limitation defines asthma. It is unfortunately difficult to directly measure airway inflammation and variable expiratory airflow inflammation in young children. Every opportunity should be exploited to define and demonstrate these two key features. The child should show clinical improvement after a correctly administered inhaled bronchodilator, or during a 2 - 3-month pragmatic trial of correctly administered inhaled controller treatment, with worsening of symptoms after treatment cessation, before asthma can be diagnosed. A four-step diagnostic approach is supported.

 

The four-step diagnostic approach in preschool-aged children

One in three children will wheeze before their third birthday. Young children are prone to recurring viral airway infections, with which wheeze can be associated. Deciding when this is an initial manifestation of asthma can be difficult. There are many other reasons for wheezing in preschool-aged children. Asthma must therefore be distinguished from these other causes. A practical approach is to follow four basic steps to distinguish asthmatic children from children who wheeze because of an alternative cause. These steps include: detailed history-taking; a clinical examination to exclude an alternative reason for wheezing; assessing inflammation; and seeking objective evidence of variable airflow limitation.

Step 1: Detailed history-taking

The history is often the most helpful instrument in diagnosing preschool-aged asthma. It should focus on two important aspects: a background history to signal the risk for the inception of asthma; and the history related to the wheeze episodes or 'chest events' themselves (Table 1).[2]

The inception of asthma is associated with a number of risk factors. The influence of the genome (e.g. parental asthma or asthma in first-degree relatives), epigenetic expression (e.g. caesarean section birth or maternal smoking during pregnancy), dysbiosis (e.g. with formula feeding and early antibiotic use), the early development of allergic sensitisation[3] and recurrence of wheeze associated with viral (or bacterial) airway infections are associated with an increased risk for the inception of asthma.[4] Early airway colonisation with encapsulated pathogens[5] and a past personal history of other allergic disease (such as atopic dermatitis or allergic rhinitis) also indicate an increased risk for the inception of asthma.

The history related to the wheeze episodes (or 'chest events') themselves provides helpful information with regard an asthma diagnosis. The decision to consider an asthma diagnosis, and to start controller therapy, is often primarily determined by:

A history of variability of airflow limitation: Clinicians must make efforts, at every opportunity, to document the response to a correctly administered rapid acting bronchodilator. A history of (preferably doctor-confirmed) bronchodilator responsiveness will support an asthma diagnosis.

Severity of 'chest events': A history of more severe wheeze (e.g. with respiratory distress or a need for oxygen supplementation) will favour an asthma diagnosis but not exclude alternative diagnoses.

Frequency and duration of episodes: Events that occur more frequently (>3 episodes per year) and that last longer (>10 days at a time) may indicate an asthma diagnosis, but will not exclude an alternative diagnosis.

Temporal pattern of symptoms: 'Chest events' that do not only occur during airway infections, but also in response to other triggers in between infections, will support an asthma diagnosis. Events that persist >3 years of age, night-time worsening, an association with exercise or environmental change (e.g. cold air exposure) will further support an asthma diagnosis.

Step 2: Exclude an alternative reason for wheezing

The next step is to consider an alternative diagnosis for wheezing. This step is especially important at a younger age. The aim of the clinical examination is often not to find signs of asthma, but rather to document the presence or absence of atopic disease (atopic dermatitis, allergic rhinitis, etc.) and to seek clinical findings that would indicate an alternative diagnosis (e.g. digital clubbing, growth faltering, asymmetric wheeze, etc.) (Table 2).

Appropriate special investigations (chest X-ray, sweat chloride and contrast studies) may be needed to exclude an alternative diagnosis. A poor response to controller therapy will warrant referral to a specialist for specialised investigations such as bronchoscopy.

Step 3: Assessing inflammation

Asthma is characterised by chronic airway inflammation. Direct assessment of airway inflammation may not be practical, but indirect cues can inform an opinion on the nature of underlying airway inflammation. Biomarkers that predict asthma, and likely improvement on corticosteroid treatment, include markers of type 2 inflammation such as serum eosinophilia and aeroallergen sensitisation determined through antigen-specific IgE skin-prick testing or ImmunoCAP. Clinical findings of other atopic disease (e.g. atopic dermatitis and allergic rhinitis) may support an asthma diagnosis.

A pragmatic therapeutic trial will confirm the presence of corticosteroid-responsive inflammation. A step-wise trial of correctly administered low-dose inhaled corticosteroid (ICS) should be carried out when starting treatment in any child with a wheezing disorder. Any treatment given should be viewed as a therapeutic trial, and the initial treatment response must be evaluated in 6 - 8 weeks.[2,4,6,7l If there is no clinical response to correctly administered ICS therapy, this should be discontinued, and the child investigated further. Symptoms that resolve during ICS therapy may be due to the natural history of a preschool wheezing disorder or to an effect of treatment. This must be distinguished by withdrawing treatment again. Treatment should only be restarted if symptoms recur. An ongoing benefit of ICS treatment should be reviewed every 3 months, and the ICS kept at the lowest possible dose for symptom control.[6-9]

Step 4: Seek objective evidence of variable expiratory airflow limitation

It is seldom possible to perform objective measurements on variable expiratory airflow limitation in young children. A clinical assessment of the response to correctly administered rapid-acting inhaled bronchodilator can be helpful. The clinician should pursue every opportunity to document improvement in wheeze and hyperinflation after the administration of a rapid-acting inhaled bronchodilator. The more it is confirmed clinically, the more likely that the correct diagnosis is asthma; and conversely the more it cannot be confirmed clinically, the more unlikely an asthma diagnosis will be.

 

Diagnosing asthma in school-aged children

For children >6 years of age, the same diagnostic steps should be followed. A proper history, exclusion of an alternative reason for wheezing and an assessment for inflammation should still be undertaken. Objective evidence of variable expiratory airflow limitation can now be demonstrated, and should ideally be investigated before commencement of controller therapy. Peak expiratory flow (PEF) measurements or preferably spirometry can be used (Table 3).[10] Normal tests do not exclude the diagnosis of asthma.[11] In the case that the history is suggestive of asthma, and the spirometry does not support the diagnosis, other specialised tests such as exercise bronchoprovocation or methacholine challenge may be done by a pulmonologist to confirm the diagnosis.

 

Assessment of asthma control and future risk

Asthma control means the extent to which the effects of asthma can be seen in the patient, or to which they have been reduced or removed by treatment.[2] Evaluation of asthma control includes two broad concepts, namely symptom control and future risk of adverse outcomes. Symptom control is assessed by frequency of symptoms, reliever medication use and activity limitation over the last week and month. Formal tools that provide scores to distinguish levels of symptom control (e.g. the Childhood Asthma Control Test (c-ACT) and Asthma Control Questionnaire (ACQ)) can offer insight into asthma control.[121 Future risk refers to the possibility of exacerbations, medication side-effects (oral symptoms and growth in children) or loss of lung function. No test is a gold standard, and all tests must be used in conjunction with a good history and clinical examination to assess control.[13,14] After initiation of treatment, it is essential to assess asthma control at every follow-up visit, no less than 6-monthly, and to adjust treatment accordingly.

Asthma control is significantly more likely in patients who are educated (know their disease), are regularly taught to use the inhaler device, are encouraged to use controller medication regularly and have a written action plan and educational material (www.allergyfoundation.co.za). It is important in patients with problematic severe asthma to distinguish between 'difficult asthma' due to poor adherence and/or incorrect inhaler technique and/or environmental or social factors, 'asthma plus' due to associated comorbidities, and true 'severe therapy-resistant asthma'.[15] If control is sub-optimal, check for all reasons, and educate the patient. A small number of patients need treatment adjustment (Tables 4 and 5).

 

Goals of asthma treatment

The long-term goals of asthma management include the following:

to achieve good symptom control

to maintain normal activity levels

to minimise future risk of asthma-related mortality

to reduce exacerbations

to maintain lung function and normal lung development

to minimise side-effects of treatment

to provide a written action plan

to consider the patient's own goals with regard to treatment

The goals of asthma management can only be achieved through a good understanding between the patient/parent/caregiver and the medical team. A cycle of assess (diagnosis, symptom control, risk factor assessment, medication technique and adherence), adjust treatment (medications, non-pharmacological strategies, treatment of modifiable risk factors) and review response (medication effects and side-effects), in combination with education of both the parent/ caregiver and the child with regard to effective inhaler use, adherence, symptom monitoring and a written personalised action plan, should be carried out at every visit. Medication should be adjusted up or down depending on the level of asthma control, and the lowest effective dose of ICS should always be sought.

 

Conclusion

The diagnosis of asthma in a child, especially at preschool age, can be complex, and should be considered in any child with recurrent episodes of wheeze and tight chest with or without cough that vary over time and improve after a correctly administered rapid-acting inhaled bronchodilator. Assessment of airway inflammation and objective evidence of variable expiratory limitation should be sought at every opportunity. Asthma control refers to the degree to which the manifestations and risk of asthma have been reduced by effective management, and should be assessed at every visit. Measuring control helps to determine whether treatment should be adjusted up or down or maintained. Patient education is key to attaining the goals of asthma management.

Declaration. None.

Acknowledgements. None.

Author contributions. Equal contributions.

Funding. None.

Conflict of interest. None.

 

References

1. Motala C, Green RJ, Manjra AI, Potter PC, Zar HJ. Guideline for the management of chronic asthma in children - 2009 update. S Afr Med J 2009;99(12):897-912.         [ Links ]

2. Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention, 2020. Available from www.ginasthma.org (a. Accessed 1 March 2021).         [ Links ]

3. Sly PD, Boner AL, Bjorksten B, et al. Early identification of atopy in the prediction of persistent asthma in children. Lancet 2008;372:1100-1106. https://doi.org/10.1016/S0140-6736(08)61451-8        [ Links ]

4. Jackson DJ, Gern JE, Robert F, et al. The contributions of allergic sensitization and respiratory pathogens to asthma inception. J Allergy Clin Immunol 2016;137(3):659-665. https://doi.org/10.1016/j.jaci.2016.01.002        [ Links ]

5. Bisgaard H, Hermansen MN, Buchvald F, et al. Childhood asthma after bacterial colonization of the airway in neonates. N Engl J Med 2007;357:1487-1495. https://doi.org/10.1056/NEJMoa052632        [ Links ]

6. Brand PLP, Caudri D, Eber E, et al. Classification and pharmacological treatment ofpreschool wheezing Changes since 2008. Eur Respir J 2014;43(4):1172-1177. https://doi.org/10.1183/09031936.00199913        [ Links ]

7. Bush A, Ngakumar P. Preschool wheezing phenotypes. Eur Med J 2016;1(1):93-101.         [ Links ]

8. Bisgaard H, Hermansen MN, Loland L, Halkjaer LB, Buchvald F. Intermittent inhaled corticosteroids in infants with episodic wheezing. N Engl J Med 2006;354(19):1998-2005. https://doi.org/10.1056/NEJMoa054692        [ Links ]

9. Guilbert T, Morgan WJ, Zeiger RS, et al. Long-term inhaled corticosteroids in preschool children at high risk for asthma. N Engl J Med 2006;354(19):1985-1997. https://doi.org/10.1056/NEJMoa051378        [ Links ]

10. Masekela R, Risenga SM, Kitchin OP, et al. The diagnosis of asthma in children: An evidence-based approach to a common clinical dilemma. S Afr Med J 2018;108(7):540-545. https://doi.org/10.7196/SAMJ.2018.v108i7.13167        [ Links ]

11. Galant SP, Morphew T, Newcomb RL, Hioe K, Guijon O, Liao O. The relationship of the bronchodilator response to poor asthma control in children with normal spirometry. J Pediatr 2011;158(6):953-958. https://doi.org/10.1016/j.jpeds.2010.11.029        [ Links ]

12. Deschildre A, Pin I, El Abd K, et al. Asthma control assessment in a pediatric population: Comparison between GINA/NAEPP guidelines, Childhood Asthma Control Test (C-ACT), and physician's rating Allergy 2014;69(6):784-790. https://doi.org/10.1111/all.12402        [ Links ]

13. Green RJ, Klein M, Becker P, et al. Disagreement between common measures of asthma control in children. Chest 2013;143(1):117-122. https://doi.org/10.1378/chest.12-1070        [ Links ]

14. Dinakar C, Chipps BE, AAP Section on Allergy and Immunology, AAP Section on Pediatric Pulmonology and Sleep Medicine. Clinical tools to assess asthma control in children. Pediatrics 2017;139(1):e20163438. https://doi.org/10.1542/peds.2016-3438        [ Links ]

15. Bush A, Fleming L, Sagalani S. Severe asthma in children. Respirology 2017;22(5):886-897. https://doi.org/10.1111/resp.13085        [ Links ]

 

 

Correspondence:
A van Niekerk
andre@prakmed.co.za

Accepted 2 June 2021

Creative Commons License Todo o conteúdo deste periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons