Paediatrics JC121: A Child With Cough: Acute And Chronic Cough In Children Flashcards
Cough
Under both Voluntary + Involuntary control
Function:
- Clear airways of secretions: Primary mechanism for secretion removal (when respiratory cilia are damaged by inflammation)
Cough reflex:
- protects airway following inhalation of foreign material (e.g. food, secretions)
Cough receptors:
- located with epithelium of pharynx, larynx, trachea, major bronchi
- stimulated mechanically, chemically, thermally
- stimulated by local mediators: histamine, prostaglandins, leukotrienes
- stimulated by local bronchoconstriction
- also in pharynx, paranasal sinuses, stomach, external auditory canal (source of persistent cough may not be in the lungs, i.e. cough =/= lung problems)
Reflex arc (involuntary):
- afferent fibres from Vagus nerve to cough centre in upper brainstem
- efferent fibres from Vagus nerve + Spinal cord to larynx, diaphragm, abdominal muscles to produce a cough
Higher cortical control of visceral reflex
- cough inhibition + voluntary cough
Causes of cough
- Respiratory
- URTI
- Post-nasal drip syndrome (Upper airway cough syndrome)
- Asthma
- Aspiration
- Pneumonia / Pneumonitis
- Bronchiectasis - Non-respiratory
- Heart failure
- GER
- ACEI
- Psychogenic / Habit cough
***History taking in Acute cough
- Who
- Age —> Likely organisms (e.g. acute bronchiolitis in <2 yo)
- Previously healthy? —> Community / Hospital-acquired
- Immunocompromised? (e.g. HIV-infected) —> Opportunistic organism
- Neurologically impaired? —> Aspiration pneumonia
- Atopic? —> Asthma / Post-nasal drip (∵ Allergic rhinitis)
- Live at home / institution? —> Community-acquired - What is the cough?
- Dry —> Mycoplasma, Psychogenic, Asthma, Coronavirus
- Productive —> Pneumonia, Bronchiectasis
- Blood-stained, colour? —> Pneumonia, Bronchiectasis, TB, Excoriated airway
- Barking? Brassy? —> Croup
- Wheezy? —> Asthma, Acute bronchiolitis
- Paroxysmal?
- Alleviating / Aggravating factors - When
- After feeding? —> GER
- Middle of night? —> Asthma, Sinusitis
- Worse when weather changes / turns cold? —> Asthma, Reactive airway
- When someone smoke?
- With exertion? —> Heart failure, Asthma
- With fever? —> Infection
- With runny nose?
- Soon after lying down —> Post-nasal drip
- When nervous / resolves with sleep —> Psychogenic, Habit -
How long?
- Acute vs Subacute vs Chronic
Dry vs Productive cough
Productive:
- indicate Secretions from LRT —> i.e. Lower airway is involved
- but beware of “sputum” sound described by parents
- beware Sputum (Exudates) vs Mucus
Mucus:
- produced by goblet cells + submucosal glands under normal situation —> may ↑ in illness (e.g. infection, smoking)
—> Nasal mucus
—> Lower airway mucus (trachea, bronchus, bronchioles) —> Sputum / Phlegm
Exudates:
- protein-rich fluid leaked from capillaries
- produced in alveoli (LRT) due to inflammatory process due to usually infection
Duration of cough
Distinguish Acute vs Chronic cough
- Acute: recent onset, last <3 weeks
- Most common stimulus of cough: Irritation / Inflammation of respiratory epithelium
Causes of Acute cough:
1. Acute Viral URTI (account for most acute cough at all ages)
- Self-limiting
- lasts 1-3 weeks
- URI: Viral only (influenza, RSV, parainfluenza, adenovirus, rhinovirus, human coronavirus, human metapneumovirus, bocavirus)
- Acute LRTI
- LRI: Viral, Bacterial (Strept. pneumoniae, Moraxella catarrhalis, Hib, Pseudomonas if immunocompromised, Chlamydia if neonate) - Exacerbation of pre-existing condition
- Asthma, Bronchiectasis, Post-nasal drip syndrome (Upper airway cough syndrome)
***P/E of Acute cough
- Severity
- need supportive treatment? - Etiology
- infectious vs non-infectious
- infectious: Can you rule out LRTI? (need to find out likely organism for appropriate treatment e.g. antibiotics)
- non-infectious: Allergy? (nasal (e.g. post-nasal drip), airway (reactive airway / asthma), both?) - Temperature (fever)
- Vital signs
- Respiratory distress
- RR —> tachypnea in children: >60 for <2 months, >50 for 2-12 months, >40 for >1 yo (記: 654, 2-12 months)
- Retraction / Insucking / Use of accessory muscles
- Cyanosis, SaO2
- Dyspnea, SOB - Chest exam
- deformity
- percussion
- auscultation (wheeze, crepitations, rhonchi) - Associated findings
- skin rash, eczema, tonsils, LN, rhinorrhoea
Evaluation of Acute cough
Absence of fever, tachypnea, chest signs
—> most useful for ruling out LRT involvement
Most children with cough due to simple URTI do ***NOT require any investigations (e.g. CXR)
CXR should be consider when presence of:
1. LRT signs (+/-)
2. Relentlessly progressive cough (e.g. >2 weeks)
3. Haemoptysis
4. Undiagnosed chronic respiratory disorder
Other investigations depending on your DDx:
1. CBC + D/C (e.g. Neutrophils)
2. Nasopharyngeal aspirates / Nasopharyngeal swabs for common viruses + mycoplasma
3. Sputum for Gram stain + Culture (if child old enough to produce sputum)
4. Blood culture (low detection rate even if bacterial etiology)
***Approach to arrive at Dx for acute cough
- Acute URI
- Coryzal (Nasal) symptoms
- Fever
- Sore throat - Croup syndrome
—> Viral croup
—> Recurrent spasmodic croup
—> Bacterial tracheitis
- Stridor
- Barking (like a seal) / Croupy cough
- Hoarseness
- +/- Fever - LRT illness
—> Acute bronchiolitis (wheeze (∵ inflammatory exudates in airway) +/- crepitations, usually due to RSV, HMPV (Human metapneumovirus))
—> Pneumonia (viral / bacterial)
—> Asthma
- Respiratory distress
- Tachypnea
- Increased work of breathing
- Lower chest signs (crepitations, wheeze, rhonchi)
- Fever - Allergic / Atopic illness
—> Post-nasal drip from allergic rhinitis
—> Reactive airway / asthma
- Seasonal, Diurnal variation
- Associated with Rhinitis, Posture (cough more when lying down), Clearing of throat, Triggers (e.g. dust, pollutant, pollen) - Acute exacerbation of chronic respiratory disorder
—> Bronchiectasis
- Failure to thrive
- Finger clubbing
- Chest deformity
- Features of atopy
Chronic cough
American College of Chest Physician Guideline:
- Paediatric (<15 yo) chronic cough: Daily cough lasting >4 weeks
British Thoracic Society:
- Cough >8 weeks
- Grey area of subacute cough between 2-8 weeks
Subdivided into:
- Specific cough (cough with S/S suggestive of associated problem)
- Nonspecific cough (dry cough in absence of an identifiable respiratory disease of known etiology)
Consider Duration + Intensity!!!
***History taking of Chronic cough
-
How did the cough start?
- Very acute / After choking —> Inhaled foreign body
- With URI —> Post-viral cough -
When did it start?
- Neonatal onset —> Aspiration (e.g. TE fistula), Congenital malformation, Cystic fibrosis, Primary cilial dyskinesia -
Quality of cough
- Productive (moist / wet) —> Chronic suppurative disease (e.g. Bronchiectasis)
- Paroxysmal spasmodic cough +/- Whoop —> Pertussis
- Haemoptysis —> TB in adolescents (like in adults, TB does not present as haemoptysis in children), Bronchiectasis, AV malformation
- Bizzare honking cough which ↑ with attention —> Psychogenic cough
- Dry repetitive, disappears with sleep —> Habit cough - What triggers the cough?
- Exercise, cold air, early morning —> Asthma
- Feeding —> Recurrent aspiration
***S/S of respiratory / systemic disease
- Wheeze (obstruction of lower airway)
- Intrathoracic airway lesion (e.g. asthma, foreign body)
- Extraluminal compression - Crepitation
- Parenchymal disease - Chest pain
- Asthma
- Increased respiratory distress (parenchymal disease)
- Arrhythmia -
Chest wall deformity
- Chronic airway / parenchymal disease -
Digital clubbing
- Chronic suppurative lung disease - Daily moist / productive cough
- Suppurative lung disease -
Failure to thrive
- Serious systemic including pulmonary illness - Feeding difficulties
- Serious systemic including pulmonary illness
- Aspiration - Hypoxia / Cyanosis
- Airway / Parenchymal disease
- Cardiac disease - Neurodevelopmental abnormality (e.g. Cerebral palsy)
- Aspiration lung disease - Recurrent pneumonia
- Immunodeficiency
- Congenital lung abnormalities
- TE fistula
Specific cough:
1. Whooping cough
- Pertussis (∵ small airway in children —> cannot breathe —> deep breath —> whooping noise)
- Barking / Brassy cough
- Croup
- Tracheomalacia (cartilage that keeps the airway (trachea) open is soft such that the trachea partly collapses especially during increased airflow)
- Habit cough - Paroxysmal (+/- Whoop)
- Pertussis
- Mycoplasma
- Parapertussis
- Virus - Nocturnal (middle of night)
- U/L respiratory allergy
- Sinusitis - Wheezy / Tight
- Reactive airway - Staccato cough (inspiration between each single cough)
- Chlamydia - Honking
- Psychogenic
- Habit
—> Non-sensitive / Non-specific: Only validated in Brassy vs Non-brassy cough for tracheomalacia
Clues from Age of onset of cough
Infancy:
1. Aspiration
2. Reactive airway
3. Congenital malformation
- Laryngotracheomalacia / Bronchomalacia
- Vascular compression (Ring / Sling innominate artery)
4. Infection
- Chlamydia
- Pertussis
- TB
- Post-RSV
5. Congenital heart disease
6. Passive smoking
Early childhood:
1. Aspiration
2. Asthma (Recurrent reversible obstruction of reactive airway)
3. Bronchiectasis
- Immunodeficiency
- Cystic fibrosis
- Post-infectious
4. Infection
- Viral
- TB
- Mycoplasma
- Fungal
5. Sinusitis
Late childhood / Adolescence:
1. Aspiration (degenerative neuromuscular disease)
2. Asthma
3. Bronchiectasis
- Immunodeficiency
- Cystic fibrosis
- Post-infectious
4. Infection
- Viral
- TB
- Mycoplasma
- Fungal
5. Sinusitis
6. Smoking (active + passive)
7. Psychogenic
8. Mediastinal tumour
Non-specific cough
Dry cough in absence of an identifiable respiratory disease of known etiology
Causes:
1. Usually post-viral cough
2. Another episode of acute infection
3. Others (Foreign body, Asthma, GERD etc.)
Evaluate:
1. Tobacco smoking / other pollutants
- prevalence of chronic cough in children <11 yo with 2 smoking parents: 50%
2. Child’s activity (every now and then?)
3. Parental expectations + concerns
4. Watch, Wait, Review
***P/E of Chronic cough
- Growth + Development / Failure to thrive
- Respiratory distress
- Finger clubbing
- URT
- signs of Sinusitis (facial pain, persistent purulent nasal discharge)
- signs of Allergic rhinitis (nasal obstruction, nasal discharge) - LRT
- chest deformity (Harrison sulcus (diaphragm always in tension —> pulls the softened bone inward), Pectus carinatum, ***Barrel chest)
- hyperresonance (air trapping)
- crepitations, wheeze, rhonchi - Cardiac
- murmur
- heart failure - Skin
- eczema
Investigations of Cough
Has to be Developmental appropriate:
1. CXR
2. Peak flow +/- Lung function study
- for obstructive / restrictive diseases
- usually >=7 yo (∵ need cooperation)
3. CBC + D/C
4. Mantoux test / PPD / IGRA / Sputum / Early-morning gastric aspirate (for TB)
5. HRCT / MRI
6. Cilia study (for primary ciliary dyskinesia)
7. Immunoglobulin pattern (for Ig deficiency)
8. 24 hours pH study (for reflux)
9. Video fluoroscopy (for aspiration)
10. Bronchoscopy
