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Last reviewed: 9 Mar 2025
Last updated: 02 Apr 2025

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • wheezing
  • expiratory airflow limitation
  • shortness of breath
  • tachypnoea
  • chest tightness

Other diagnostic factors

  • cough
  • exercise limitation
  • tachycardia
  • inability to speak or feed
  • intercostal, sub-costal, or sternal retraction
  • accessory muscle use
  • pulsus paradoxus
  • sleep disturbance
  • bradycardia
  • cyanosis
  • exhaustion
  • decreased consciousness level

Risk factors

  • viral infection
  • uncontrolled asthma symptoms
  • high use of short-acting beta-2 agonists (SABA)
  • inadequate use of inhaled corticosteroids (ICS)
  • incorrect inhaler technique
  • low forced expiratory volume in 1 second (FEV₁)
  • high bronchodilator reversibility
  • inhaled allergens
  • exercise
  • poor adherence with regular asthma medication
  • history of asthma
  • history of other atopic disease
  • family history of atopic disease
  • history of hospitalisation for asthma exacerbations
  • one or more severe or life-threatening exacerbations in the past 12 months
  • low socio-economic status
  • air pollution
  • vitamin D deficiency
  • obesity
  • younger age
  • smoking
  • vaping
  • bacterial infection
  • emotion
  • non-steroidal anti-inflammatory drug (NSAID) use
  • gastro-oesophageal reflux disease
  • chronic rhinosinusitis
  • African-American ethnicity
  • low parental education

Diagnostic investigations

1st investigations to order

  • response to treatment with a short-acting beta-2 agonist (SABA)
  • peak expiratory flow or FEV₁
  • oxygen saturation

Investigations to consider

  • arterial or venous blood gases
  • chest x-ray
  • fractional exhaled nitric oxide (FeNO)

Treatment algorithm

Contributors

Authors

Paul D. Robinson, MBChB, MRCPCH, FRACP, PhD, ATSF

Respiratory and Sleep Physician

Conjoint Professor

University of Queensland

Respiratory and Sleep Physician

Queensland Children's Hospital

Brisbane

Queensland

Australia

Disclosures

PDR declares that he has no competing interests.

Anne Chang, MBBS, FRACP, MPHTM, PhD

Professor

Menzies School of Health Research

Charles Darwin University

Northern Territory

Respiratory and Sleep Physician

Queensland Children's Hospital

Queensland University of Technology

Brisbane

Australia

Disclosures

AC is an author of references cited in this topic.

Peer reviewers

Amanda Messinger, MD, MSCI

Assistant Professor of Pediatrics

Section of Pediatric Pulmonary and Sleep Medicine

University of Colorado School of Medicine

Colorado

CO

Disclosures

AM declares that she has no competing interests.

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