Cough in Children Algorithm

Safety

Red Flags — Exclude emergency respiratory causes first

Done

Cough is rarely life-threatening but these presentations demand immediate action.

Acute stridor at rest Suggests croup (severe), epiglottitis, bacterial tracheitis, or foreign body → 999 — do not examine throat

Respiratory failure SaO₂ <92%, cyanosis, exhaustion, inability to complete sentences → 999

Choking episode / sudden onset Inhaled foreign body — especially age 6mo–3yr, during meal/play → 999; back blows if conscious + choking

Whooping cough — infant <6 months Paroxysmal cough + whoop / cyanosis / apnoea → Same-day hospital (apnoea risk)

Haemoptysis Blood in sputum in child → urgent investigation. Consider bronchiectasis, TB, CF → Same-day paeds

Severe wheeze / acute asthma Too breathless to talk, silent chest, HR >140 (<5yr) or >125 (≥5yr), SaO₂ <92% → 999

Suspected epiglottitis Drooling, muffled voice, tripod position, fever + stridor = rare but rapidly fatal → 999 — do NOT examine

Clubbing + chronic cough Suggests cystic fibrosis, bronchiectasis, malignancy → Urgent paeds referral

Foreign body inhalation kills rapidly from complete obstruction. Peak age is 6 months to 3 years. The classic history is sudden onset cough/choking during eating or play. CXR may show hyperinflation unilaterally (ball-valve effect) but a normal CXR does NOT exclude foreign body — rigid bronchoscopy is required if clinical suspicion is high.

Epiglottitis is rare since Hib vaccination but Hib uptake has declined. It is rapidly fatal — do NOT attempt to examine the throat or lay the child down. Call 999 and keep child upright with parent. Anaesthetic/ENT team are needed for airway management.

Diagnose

Characterise the cough — duration, quality, timing, triggers

Done

The character of the cough is your most important diagnostic tool — it narrows differentials before examination.

Acute (<3 weeks)

Viral URTI (most common), croup, bronchiolitis, pneumonia, pertussis, foreign body, asthma exacerbation.

Subacute (3–8 weeks)

Post-infectious cough (most common), pertussis, mycoplasma, early asthma. Consider COVID-related cough.

Chronic (>8 weeks)

Asthma, allergic rhinitis (post-nasal drip), recurrent viral infections, GORD, CF, tracheomalacia, habit cough, protracted bacterial bronchitis (PBB).

Barking / brassy

Croup (laryngotracheitis), tracheomalacia, subglottic stenosis, habit cough. Associated stridor in croup.

Paroxysmal + whoop

Pertussis (whooping cough) — regardless of vaccination status. Post-tussive vomiting. Cyanosis in infants.

Wet / productive

Bacterial infection, PBB, bronchiectasis, CF. Wet cough >4 weeks → consider PBB. Chronic wet cough = red flag for structural disease.

Dry / non-productive

Asthma, viral, allergic, habit/tic cough, ACE inhibitor (adolescents on medication).

Nocturnal predominance

Asthma (classic — wakes child), GORD, post-nasal drip. Ask specifically: does it wake the child?

Exercise-triggered

Exercise-induced bronchoconstriction / asthma. Cold air triggers also suggest asthma.

Duration is the most powerful differentiator. Over 95% of acute coughs are viral and self-limiting. Chronic cough (>8 weeks) has a completely different differential and often requires investigation. The BTS guideline (2008) recommends classifying cough by duration as the first step.

Protracted bacterial bronchitis (PBB) is under-recognised — wet cough >4 weeks responding to 2 weeks of amoxicillin. It is the most common cause of chronic wet cough in under-6s. Failure to treat leads to bronchiectasis.

Diagnose

Age-based differential diagnosis framework

Done

Age shapes the differential — many diagnoses are age-specific.

<1 year

Bronchiolitis (RSV, Oct–March), pertussis, viral URTI, GORD, tracheomalacia, CF (if faltering growth). Asthma diagnosis not made under 1yr — wheeze is common from viral-induced wheeze.

1–5 years

Viral URTI (most common), viral-induced wheeze, croup (6mo–6yr peak), foreign body, asthma (if recurrent wheeze), PBB.

5–12 years

Asthma (new or undiagnosed), allergic rhinitis + PND, mycoplasma pneumonia (school-age dry cough), pertussis, habit cough.

Bronchiolitis criteria

Age <12 months. Coryzal prodrome → wheeze + crackles + subcostal recession. Peak at day 3–5. Mostly viral, self-limiting. Admit if SaO₂ <92%, poor feeding (<50%), apnoea, premature / under 2 months.

Croup severity

Mild: barking cough, no stridor at rest → oral dexamethasone 0.15mg/kg single dose. Moderate: stridor at rest → A&E. Severe: stridor + recession → 999. Dexamethasone NNT=5 for symptom improvement.

Asthma likelihood

Use BTS/SIGN probability score: wheeze + atopy + FHx asthma + response to bronchodilator → high probability. Under 5: cannot do spirometry — use trial of ICS + SABA.

Asthma cannot be reliably diagnosed under 5 years because spirometry is not feasible and wheeze is common with viral infections ("viral-induced wheeze"). BTS/SIGN 2019 recommends a structured probability approach rather than reflexive diagnosis in young children.

Bronchiolitis affects 1 in 3 infants in the first year and is the most common cause of hospitalisation in this age group. The NICE NG9 guideline gives clear admission criteria — SaO₂, feeding, apnoea history, and age are the key determinants.

Diagnose

Targeted Examination

Done

Respiratory rate

Age-specific norms: <2mo >60, 2–12mo >50, 1–5yr >40, 5–12yr >30 = tachypnoea. Key marker of severity. Count for 1 full minute.

Oxygen saturation

Pulse oximetry if available. <95% = concerning. <92% = acute severe — hospital. Normal SaO₂ does not rule out significant respiratory illness.

Respiratory signs

Intercostal / subcostal recession (increased WOB). Nasal flaring. Grunting = end-stage respiratory failure. Tracheal tug. Hyperexpanded chest (asthma/FB).

Auscultation

Wheeze: expiratory predominant (asthma, bronchiolitis). Inspiratory stridor: upper airway (croup, FB). Focal crackles: pneumonia, bronchiectasis. Bilateral fine crackles: bronchiolitis.

ENT

Nasal polyps (CF). Cobblestoning of posterior pharynx (post-nasal drip). Ear drums (AOM + cough in young child). Tonsillar hypertrophy.

Growth / nutrition

Plot on centile chart. Faltering growth + chronic wet cough → CF until proven otherwise. Finger clubbing = CF, bronchiectasis, malignancy.

Skin / allergy

Eczema, urticaria → atopic — raises asthma probability significantly. Allergic shiners, transverse nasal crease (allergic salute).

Respiratory rate is the single most sensitive examination finding for pneumonia in children — more sensitive than temperature, WBC, or CRP. A child with cough + tachypnoea should be assessed for pneumonia even without focal auscultatory findings (early lobar pneumonia may be "silent" to the stethoscope).

Faltering growth with chronic wet cough should prompt CF testing (sweat chloride or genetics referral) — CF is diagnosed late in ~20% of cases in the UK because GPs do not consider it. Early diagnosis dramatically improves prognosis.

Diagnose

Investigations — when, what, and what to avoid

Done

Acute viral cough

No investigations needed. Self-limiting in 3 weeks. CXR and bloods will not change management. Save the child from unnecessary procedures.

Spirometry

Asthma diagnosis ≥5yr FEV₁/FVC <0.7 = obstruction. Significant bronchodilator reversibility = ≥12% and >200ml improvement FEV₁. Perform when child is symptomatic if possible.

Peak flow diary

Asthma monitoring Morning + evening x 2–4 weeks. >20% diurnal variation = asthma. Easy to do at home with standard peak flow meter.

Pertussis PCR / serology

Nasopharyngeal swab PCR if cough <3 weeks. IgG serology if cough >3 weeks. Confirm for public health notification + to protect household contacts.

CXR

Indicated: Suspected pneumonia (tachypnoea + fever + crackles), suspected FB (unilateral hyperinflation), chronic wet cough ≥4 weeks, haemoptysis, clubbing, unexplained recurrent wheeze.

Sweat chloride / CF genetics

Wet cough + faltering growth + steatorrhoea + recurrent chest infections. Refer to paeds for sweat test — do not delay.

Allergy testing

Skin prick test or specific IgE (RAST) if multiple atopic features and asthma likely. Refer to paeds allergy. Not needed for routine asthma diagnosis.

Chest CT / bronchoscopy

Hospital-initiated only. For persistent bronchiectasis, recurrent aspiration, persistent atelectasis, or suspected structural anomaly.

CXR for acute cough in children without danger signs adds radiation exposure without changing management in the majority of cases. A 2012 Cochrane review found no benefit of CXR in non-severe community-acquired LRTI. Reserve for cases where the result will genuinely change management.

Spirometry is the gold standard for asthma diagnosis but is only reliable over age 5. Under 5, use a 4–8 week trial of low-dose ICS. If the cough/wheeze resolves on ICS and returns on stopping, the diagnosis is supported. Document this clearly to avoid inappropriate long-term prescribing.

Refer

Referral Criteria

Done

999

Acute severe asthma (SaO₂ <92%, silent chest, too breathless to talk). Epiglottitis. Stridor + respiratory distress. FB inhalation. Apnoea. Cyanosis.

Same-day ED

Moderate acute asthma not responding to 10 puffs salbutamol. Bronchiolitis with poor feeding / SaO₂ <92% / apnoea history. Pertussis in infant <6 months. Bacterial tracheitis.

Urgent paeds (1–2wk)

Suspected CF (wet cough + faltering growth). Bronchiectasis on CXR. Recurrent pneumonia (≥2 in 1yr). Haemoptysis. Clubbing + cough.

Paeds outpatient

Uncontrolled asthma on step 3+. Diagnostic uncertainty for asthma in child <5yr. Chronic wet cough >8 weeks without diagnosis. Suspected primary ciliary dyskinesia (recurrent otitis + bronchiectasis).

Primary care manage

Viral acute cough with green features. Mild asthma well-controlled on step 1–2. Croup — mild, responds to oral dexamethasone. Post-infectious cough resolving.

Habit cough

Honking cough disappearing during sleep, school-age child, no nocturnal symptoms → refer CAMHS / specialist respiratory. Suggestion therapy / reassurance effective in 90%.

CF diagnosis is delayed by an average of 1–2 years in children not detected by newborn screening (NBS). NBS detects ~90% but false negatives exist. Any child with chronic wet cough + faltering growth + recurrent chest infections deserves CF investigation regardless of NBS result.

Recurrent pneumonia (≥2 episodes in 12 months) should always be referred for investigation — underlying structural lesion (sequestration, congenital airway malformation), immunodeficiency, or aspiration should be excluded. These are missed in primary care.

Treat

Treatment — condition-specific drug ladder

Done

Mild croup

Oral dexamethasone Single dose

0.15 mg/kg PO single dose. Max 10mg. NNT=5. Can send home. Reassess if stridor at rest develops. Avoid in varicella.

Acute wheeze / asthma

Salbutamol MDI + spacer First-line

2–6 puffs via spacer, repeat up to 10 puffs if moderate. Prednisolone 1–2mg/kg/day (max 40mg) x 3 days if moderate/severe.

Pertussis (confirmed)

Azithromycin Within 3 weeks

Azithromycin 10mg/kg OD x 5 days (all ages). Reduces transmission; doesn't shorten cough. Notify PHE. Treat household contacts <1yr prophylactically.

Asthma Step 1SABA PRN — Salbutamol 100mcg 1–2 puffs via spacer as needed. Review if using >3 times/week.

Asthma Step 2Add ICS low dose — Beclometasone 100–200mcg BD (≥5yr). Under 5: fluticasone 50mcg BD. Review after 4–8 weeks.

Asthma Step 3ICS + LABA — Salmeterol 25mcg BD added to ICS. Or MART regime (budesonide/formoterol 100/6 1 puff BD + PRN) if ≥12yr. Refer if <5yr.

Asthma Step 4Increase ICS to medium dose + LTRA (montelukast) 4mg (<6yr) / 5mg (6–14yr) OD at night. Refer to paeds.

PBB (wet cough >4wk)

Amoxicillin 40mg/kg/day (max 1.5g/day) in 3 doses x 14 days. If fails → co-amoxiclav. Response confirms diagnosis. Recurrent PBB → refer paeds.

Viral cough

No antibiotic. Honey 2.5ml in children >1yr at night (not infants — botulism risk). OTC cough medicines not recommended MHRA <12yr. Reassure and safety-net.

Salbutamol via MDI + spacer is as effective as nebulisation in mild-moderate asthma (Cochrane 2013) and avoids hospitalisation delays. Every asthmatic child should have a spacer (e.g., AeroChamber Plus) — technique must be checked at every visit.

Honey at night reduces cough frequency in children over 1 year — a Cochrane review (2018) found a small but statistically significant benefit over no treatment. It should not be given to infants under 1 year due to infant botulism risk. OTC cough medicines have no evidence and are not recommended by MHRA for children under 12.

Montelukast for asthma: MHRA 2020 safety review highlighted neuropsychiatric side effects (sleep disturbances, nightmares, aggression, suicidal ideation). Counsel parents and document. Consider risk vs benefit especially in children with pre-existing behavioural issues.

Lifestyle

Preventive measures & self-management

Done

Inhaler technique Check at every asthma review — poor technique is the commonest cause of uncontrolled asthma. MDI + spacer = standard for under 8yr. Use InCheck DIAL or demonstrate at appointment.

Smoke-free environment Passive smoking doubles asthma risk and increases cough frequency. Every smoking parent/carer should be offered smoking cessation referral. Carbon monoxide test for parents if appropriate.

Vaccinations Annual influenza vaccine recommended for all children with asthma or recurrent LRTI. Pertussis booster in school-age if not up to date. Check immunisation record at every consultation.

Allergen avoidance House dust mite reduction (mattress covers, regular washing at 60°C, no carpet in bedroom) reduces asthma exacerbations. Pet dander avoidance if sensitised. Pollen avoidance strategies in pollen season.

Asthma action plan All asthmatics should have a written personalised asthma action plan (PAAP). Available via Asthma + Lung UK (asthma.org.uk). Review at every appointment.

Breast-feeding / diet Breastfeeding for ≥4 months reduces bronchiolitis and recurrent wheeze risk. No evidence for elimination diets unless confirmed allergy. Good nutrition supports immune function.

Inhaler technique is poor in up to 70% of asthmatic children and their carers. The most common errors are lack of spacer use, failure to actuate during inhalation, and not holding breath after. Improving technique can reduce exacerbation frequency by 30–40% without medication change.

Environmental tobacco smoke (ETS) exposure in children with asthma increases hospitalisation risk by 2-fold and doubles the number of GP consultations. Parental smoking cessation is the most effective single intervention for childhood respiratory health but requires sensitive non-judgemental communication.

Safety

Follow-up, Safety-Netting & Monitoring

Done

Acute viral cough

No routine follow-up needed. Safety-net: return if cough worsens, lasts >3 weeks, or new symptoms develop (fever, wheeze, failure to feed).

Asthma — new diagnosis

Review at 4–8 weeks to assess response to ICS. Annual asthma review (NHS QOF). Check inhaler technique, PAAP, reliever use. Step down after 3 months of good control.

Bronchiolitis

Review at 24–48hrs if managed at home. Admit if not improving, SaO₂ drops, or feeding worsens. Most resolve by 2–3 weeks.

Pertussis

Notify PHE online (pertussis is notifiable). Household contacts <1yr → prophylactic azithromycin. Child excluded from school/nursery until 48hrs of antibiotics completed.

Wet cough / PBB

Review at 2 weeks — has cough resolved? If not → repeat course or broaden antibiotic. If third course fails → paeds referral for bronchoscopy/BAL.

Call 999 if:

Child stops breathing / turns blue. Wheeze not responding to salbutamol. Child collapses or cannot be roused. Stridor at rest getting worse.

Same-day if:

SaO₂ drops below 95% at home. Cough becomes suddenly much worse with distress. Feeding stops completely. Parent very worried — trust parental instinct.

Annual asthma review is a QOF target (QOF indicator AST) and has been shown to reduce asthma mortality. The UK has one of the highest rates of preventable asthma deaths in Europe — the majority related to inadequate monitoring, no PAAP, and failure to step up treatment.

The National Review of Asthma Deaths (NRAD 2014) found that 90% of asthma deaths were potentially avoidable. Common failures: no written action plan, no escalation plan communicated to parents, excessive reliance on SABA, under-use of ICS. Follow-up and monitoring saves lives.