Table 2

Different phenotypes of paediatric and adult airway disease

DiagnosisAirway inflammationInfectionFixed airflow obstructionVariable airflow obstructionOther featuresTreatments
Year one wheeze [97]NoNot known, may be acute viralMay be presentMay be present, likely bronchospasm, could be malacia, mucus or airway malaciaMay occur recurrently
Seems likely unrelated to later wheeze, poorly understood
Can trial SABA or ipratropium
Preschool wheezeMostly none, but may be eosinophilicAcute viral, bacterial or bothOften presentYes, likely bronchospasm but may be a component of malaciaMay occur recurrentlyICS only if evidence of airway eosinophilia
Can trial SABA or ipratropium
School-age asthmaUsually eosinophilic, but may be pauci-granulocyticAcute viral, bacterial or bothOften present related to impaired airway developmentYesCommonly associated with sensitisation to aeroallergens
Rhinitis, eczema and food allergy often coexist
ICS if eosinophilic, SABA, LABA, LTRA
?LAMA, AZM for pauci-granulocytic
Aspiration syndromesNeutrophilicMay be bacterial, especially anaerobesOften acquiredMay have bronchospasm
May have variable atelectasis
Neuromuscular disease; structural anatomical abnormalitiesTreat underlying cause
ObesityMay be eosinophilic [87], or IL-6 mediated [88] (systemic inflammation)Not knownDysanaptic airway growth  [89]May have bronchospasm
May have variable atelectasis
Obstructive sleep apnoea
Metabolic syndrome
Weight reduction
Ensure there really is an airway disease, not deconditioning
ICS only if evidence of airway eosinophilia; can trial SABA or ipratropium
Persistent bacterial bronchitisNeutrophilicBacterial, viralNot well studied, probably not early onYes, intraluminal secretionsMay occur recurrently
Coarse crackles, squeaks and intraluminal mucus often seen in adults (diffuse panbronchiolitis type pattern)
Oral co-amoxiclav for 2 weeks [90]; investigate if no response or relapses
Long-term macrolides often highly effective but must exclude an underlying diagnosis [91]
CF, PCD, bronchiectasisNeutrophilicBacterial, viralYes, often progressiveYes, intraluminal secretionsMay occur recurrently
Coarse crackles, squeaks and intraluminal mucus often seen
Antibiotics, airway clearance, see standard guidelines [96]
(Chronic) obliterative bronchiolitisNone in chronic phaseNone in chronic phaseYesNoAssociated with autoimmunity in adults (i.e. rheumatoid arthritis)
Florid form seen in graft versus host disease
Chronic bronchiolitis (chILD)LymphocyticNoneNot well studied, probably not early onNot well studied, probably notInvestigate and treat underlying cause, usually an immunodeficiency
Lung disease of prematurityNone unless also atopic [92]NoneYes, even in late preterm and early term survivors [93]Yes, bronchodilator reversible [94]Frequent comorbidities include neurodevelopmental handicap, retinopathy of prematurity, abnormal control of respirationBronchodilators as needed, not ICS unless coincidentally atopic
Sickle cell anaemia [98]NoneNoneYesNoPainful and occlusive vascular crises in multiple organsSee standard guidelines, no airway disease treatment unless coincidentally atopic
Post NEHI [95]Probably noneNoneProbably, not well studiedProbably, not well studiedNot well studied; not ICS responsive, SABA as needed
Tracheo-bronchomalacia [99]NoneNone unless associated with aspirationNone unless associated with a relevant comorbidityYes, may be worsened by SABATreat underlying cause along standard guidelines and any secondary infection with antibiotics and airway clearance
Adult-onset asthma (most likely adult recrudescence rather than arising de novo)Highly eosinophilicUnusualCan occurShort-term variable airflow obstruction often not prominent, although airflow obstruction is seen in the context of an attackRecurrent asthma attacks often the most prominent manifestation
Mucus plugging may be a key mechanism for non-bronchodilator airflow obstruction
Chronic rhinosinusitis and nasal polyposis commonly seen
Type-2 biologics often highly effective
COPDVariable (all of the above can be seen)Viral and bacterialBy definitionCan be presentHighly heterogeneous condition, likely related to all of the above; multiple systemic comorbidities associatedBronchodilators are the mainstay
Corticosteroids helpful if evidence of type-2 inflammation
Unexplained chronic coughMay be lymphocytic but not well studiedUnusualNoNoCommon in perimenopausal women
Heightened cough reflex
No well-established treatments, although P2×3 antagonists look promising

AZM: azithromycin; chILD: children's interstitial lung disease; ICS: inhaled corticosteroids; IL: interleukin; LABA: long-acting β2-agonist; LAMA: long-acting muscarinic agents; LTRA: leukotriene receptor antagonist; NEHI: neuroendocrine cell hyperplasia of infancy; SABA: short-acting β2-agonist.