- Viral (mostly parainfluenza), peak age 6 months–3 years
- Classic triad: barking cough, inspiratory stridor, hoarse voice
- Preceded by URTI symptoms (coryza, low-grade fever)
- Key: keep child calm — crying worsens obstruction
- Mild–moderate: oral prednisolone 1 mg/kg OR dexamethasone 0.15–0.6 mg/kg
- 🚨 Severe: nebulised adrenaline 4 mL 1:1000 + immediate ambulance transfer
M111
Acute Upper Respiratory Tract Infections
URTI vs LRTI — Key Differentiators
| Feature | URTI | LRTI |
|---|---|---|
| Site | Larynx and proximal airways | Trachea and distal airways |
| Systemic symptoms | May be present without localising signs | Common — fever, malaise, myalgia |
| Localising signs | Cervical lymphadenopathy | Crepitations, rhonchi, signs of respiratory distress (tachypnoea, retractions, cyanosis) |
| Key symptoms | Rhinorrhoea, sore throat, mild cough | Productive cough, wheeze, breathlessness, chest pain |
| Common syndromes | Coryza, ILI, Sinusitis, Pharyngitis, Otitis Media | Bronchitis, CAP, Atypical pneumonia, TB |
Antibiotic Decision Framework in URTI
| Doctor's Assessment | Patient Expectation → Demands | Patient Expectation → Neutral | Patient Expectation → Refuses |
|---|---|---|---|
| Antibiotics INDICATED | Prescribe + explain rationale | Prescribe + explain rationale | Document informed refusal; advise on risks |
| UNCERTAIN indication | Consider: risk factors, comorbidities, toxicity. Review in 72h if not prescribed. | Use clinical judgment; consider delayed prescription | Symptomatic Rx; review in 72h |
| NOT indicated | Explain; offer safety-net/delayed prescription if patient insists | Reassure + symptomatic Rx | Reassure + symptomatic Rx |
Cough & Cold Medicines in Children — Current HSA Guidance
💎 Clinical Pearl
| Age Group | Antihistamines | Decongestants / Cold products | Cough suppressants (non-codeine) | Codeine |
|---|---|---|---|---|
| <2 years | NOT recommended (unless prescribed by doctor) | NOT recommended | NOT recommended | CONTRAINDICATED |
| 2–6 years | Use only if benefits outweigh risks; HCP advice essential | Use only if benefits outweigh risks | Use only if benefits outweigh risks | CONTRAINDICATED |
| 6–12 years | Use with caution; appropriate dosing | Use with caution | Use with caution | CONTRAINDICATED |
| ≥12 years | Use with appropriate dosing | Use with appropriate dosing | Use with appropriate dosing | Only if indicated; lowest effective dose, shortest duration |
| Promethazine | Contraindicated <6 months; not recommended <2 years; caution in older children | — | — | — |
Signs of Complicated/Progressive Influenza
🚨 Emergency
| System | Warning Signs |
|---|---|
| Respiratory | Cyanosis, haemoptysis, hypoxia (low SpO2), laboured breathing, shortness of breath |
| Cardiovascular | Chest pain, hypotension |
| CNS | Altered mental status, lethargy, seizures, severe weakness or paralysis |
| General | Decreased urine output, dehydration, fever persisting >72 hours, worsening after initial improvement |
Influenza — Antiviral Therapy (2025–2026)
| Agent | Route | Age | Key Feature |
|---|---|---|---|
| Oseltamivir (Tamiflu) | Oral | ≥2 weeks (treatment); ≥1 year (prophylaxis) | First-line. 5-day course. Dose-adjust for renal impairment. |
| Zanamivir (Relenza) | Inhaled | ≥7 years (treatment); ≥5 years (prophylaxis) | Avoid in asthma/COPD — bronchospasm risk. |
| Peramivir (Rapivab) | IV | ≥2 years | Single-dose IV. For hospitalised patients unable to take orals. |
| Baloxavir marboxil (Xofluza) | Oral | ≥5 years | Single-dose. PA endonuclease inhibitor. Active against oseltamivir-resistant strains. Avoid in pregnancy. |
Influenza Antiviral — When to Treat
| Scenario | Recommendation |
|---|---|
| Hospitalised with severe/complicated influenza | TREAT — regardless of duration of illness |
| High-risk outpatient (elderly, pregnant, immunocompromised, chronic disease) | TREAT — start within 48h of symptom onset |
| Healthy adult/child with uncomplicated influenza | Treatment optional; shared decision-making |
| Post-exposure prophylaxis (high-risk contact) | CONSIDER — oseltamivir or zanamivir |
| Healthy person, contact >48h ago | Do NOT prescribe prophylaxis |
Viral Exanthems — Differentiating Features
| Condition | Virus | Key Clinical Feature | Important Management Point |
|---|---|---|---|
| Measles (Rubeola) | Measles virus | Severe prodrome (fever, cough, coryza, conjunctivitis). Koplik spots before rash. Morbilliform rash while acutely ill. | Highly contagious. Preventable by MMR. Complications: otitis media, pneumonia, encephalitis. |
| Rubella (German Measles) | Rubella virus | Mild illness. Suboccipital & postauricular lymphadenopathy precede transient rash (~48h). | Congenital Rubella Syndrome if contracted in pregnancy. Preventable by MMR. |
| Roseola Infantum (Exanthem Subitum) | HHV-6 | 3 days of high fever in infants/toddlers, then rash appears as fever abruptly subsides. | Do NOT misattribute rash to antibiotic side effect. Self-limiting. |
Viral Enanthems — Key Features
| Condition | Virus | Distribution of Lesions | Key Points |
|---|---|---|---|
| HFMD | Coxsackievirus A; Enterovirus 71 (EV71) | Vesicles on hands, feet, buttocks; painful oral ulcers (posterior mouth) | EV71 can cause fatal neurological/cardiorespiratory complications. Monitor closely. Notifiable. |
| Herpangina | Coxsackievirus A | Papulovesicular ulcers on tonsillar pillars, soft palate, uvula (posterior) | Supportive only. Ensure hydration. Antibiotics NOT indicated. |
| Acute Herpetic Gingivostomatitis | HSV-1 | Vesicles/erosions on gums, buccal mucosa, tongue, lips (anterior mouth) | May be severe. Early oral acyclovir indicated. Maintain hydration. |
Viral Exanthem Images
Measles: Morbilliform rash appearing while patient is still acutely ill (fever, cough, conjunctivitis). Source: CDC/Wikimedia Commons.
Other Viral Syndromes with Unique Signs
| Condition | Virus | Unique Feature | Key Concern |
|---|---|---|---|
| Erythema Infectiosum (Fifth Disease) | Parvovirus B19 | 'Slapped cheek' → lacy reticular rash on trunk/limbs | Aplastic crisis in chronic haemolytic anaemia (e.g., sickle cell). Hydrops fetalis if infected during pregnancy. |
| Papular Acrodermatitis (Gianotti-Crosti) | EBV, CMV, Coxsackievirus, Hep B | Symmetric, non-pruritic papules on face, buttocks, limbs. May persist weeks. | Benign, self-limiting. Reassure parents. |
| STAR Syndrome | Rubella, Parvovirus B19 | Sore Throat + Arthritis + Rash — reactive polyarthritis after acute viral illness | Self-limiting. Differentiate from primary inflammatory arthritis. |
Vector-Borne URTI Mimics in Singapore
🚨 Emergency
| Condition | Key Differentiating Features | Critical Management Point |
|---|---|---|
| Dengue | Retro-orbital pain, myalgia, maculopapular rash, thrombocytopenia. Biphasic fever. Warning signs: persistent vomiting, severe abdominal pain, mucosal bleeding. | Statutory notification. Supportive care + careful fluids. Avoid NSAIDs. Avoid contact sports. |
| Chikungunya | Fever + SEVERE polyarthralgia/polyarthritis — often debilitating. Joint pain disproportionate to other features. | Supportive. NSAIDs for arthralgia (after dengue excluded). Arthralgia may persist for months. |
| Zika | Usually mild: rash, conjunctivitis, joint pain. BUT: Guillain-Barré in adults; microcephaly in neonates if infected during pregnancy. | High index of suspicion in pregnant women. Refer for monitoring. Test sexual contacts if needed. |
Dengue — Three Clinical Phases
| Phase | Timing | Clinical Features |
|---|---|---|
| Febrile | Days 1–3 | Abrupt high fever, headache, retro-orbital pain, myalgia, backache, maculopapular rash |
| Critical | Days 4–6 (last 24–48h of fever) | Defervescence — critical phase. Worsening thrombocytopenia. Warning signs: abdominal pain, persistent vomiting, mucosal bleeding, fluid accumulation, lethargy. Risk of plasma leakage, shock, organ failure. |
| Recovery | Days 7–10 | Platelet count rises. Bradycardia common. Characteristic rash: generalised erythema with 'white islands in a sea of red'. |
Sore Throat — McIsaac Score for GABHS
| Criterion | Score |
|---|---|
| Temperature >38°C | +1 |
| Absence of cough | +1 |
| Tender anterior cervical lymph nodes | +1 |
| Tonsillar swelling or exudates | +1 |
| Age 3–14 years | +1 |
| Age ≥45 years | −1 |
| Score ≤1: antibiotics NOT recommended | |
| Score 2–3: consider RADT; treat if positive | |
| Score ≥4: empirical antibiotics strongly considered |
Differentiating Viral vs Bacterial Pharyngitis
💎 Clinical Pearl
| Feature | Viral | Bacterial (GABHS) |
|---|---|---|
| Cough | Present (often prominent) | Absent |
| Coryza / rhinorrhoea | Often present | Usually absent |
| Conjunctivitis | May be present (adenovirus) | Absent |
| Diarrhoea / hoarseness | May occur | Absent |
| Oral ulcers (enanthem) | May be present (HSV, enterovirus) | Absent |
| Tonsillar exudates | Can occur (EBV) | Common |
| Onset | Gradual | Abrupt |
| Classic rash | Variable (viral exanthem) | 'Sandpaper' rash → scarlet fever |
Antibiotics for GABHS Pharyngitis
| Drug | Adult Dose (10-day PO course) | Notes |
|---|---|---|
| Penicillin V | 500 mg BD or 250 mg QDS | First-line. Narrow spectrum. No documented GABHS resistance. |
| Amoxicillin | 500 mg BD or 50 mg/kg OD (max 1g) | Broader spectrum but better palatability (paediatrics). Avoid if EBV not excluded. |
| Cephalexin (PCN allergy — non-anaphylactic) | 500 mg BD | 1st generation cephalosporin. Cross-reactivity with penicillin is low (<2%). |
| Clindamycin (PCN allergy — anaphylactic) | 300 mg TDS | Effective alternative. |
| Azithromycin (PCN allergy — anaphylactic) | 500 mg OD × 5 days | Use only if macrolide susceptibility confirmed — resistance rates increasing. |
| Clarithromycin (PCN allergy — anaphylactic) | 250 mg BD × 10 days | Alternative macrolide. |
Otitis Media — AOM vs OME
| Feature | Acute Otitis Media (AOM) | Otitis Media with Effusion (OME) |
|---|---|---|
| Definition | Middle ear fluid + acute signs of inflammation | Middle ear fluid WITHOUT acute inflammation |
| Symptoms | Otalgia, fever, irritability | Hearing loss, 'muffled' hearing, often asymptomatic |
| Tympanic membrane | Bulging, erythematous, loss of landmarks | Dull, retracted, air-fluid level visible |
| Antibiotics | Indicated in <2 years; bilateral; severe symptoms. Watchful waiting 48–72h for mild unilateral AOM ≥2 years. | NOT routinely recommended |
| First-line antibiotic | Amoxicillin 80–90 mg/kg/day (high dose) | — |
| ENT referral | For persistent/recurrent AOM, complications | Bilateral OME >3 months with hearing loss or speech delay |
Key Summary — Acute URTIs in Family Practice
Key Point
Differentiate viral from bacterial URTI using clinical features and scoring tools (McIsaac) — antibiotics are inappropriate for most URTIs
Key Point
Antibiotic stewardship: address patient ICE, use delayed prescriptions for borderline cases, safety-net all patients
Key Point
Know the URTI mimics: vector-borne diseases (Dengue, Chikungunya, Zika) are common in Singapore — maintain a high index of suspicion
Key Point
COVID-19 and Influenza: use antiviral therapy for high-risk patients early; ensure vaccination up-to-date for recommended groups
Key Point
Red flags requiring urgent action: signs of epiglottitis (DO NOT examine throat — refer immediately), complicated influenza, dengue warning signs
Key Point
Paediatric prescribing: OTC cough/cold medicines not recommended in <2 years; codeine restricted to ≥12 years only
M112
Acute Lower Respiratory Infections
Differential Diagnosis of Dyspnoea
Croup (Laryngotracheobronchitis) — Assessment & Management
Table summarising the assessment of degree of airway obstruction in croup (mild, moderate, severe, life-threatening) with corresponding clinical features and initial treatment guidelines including nebulised adrenaline, oral prednisolone, and dexamethasone.
Acute Cough Algorithm
- Systematic approach to adult with cough <3 weeks
- First: rule out life-threatening diagnoses (PE, tension pneumothorax, anaphylaxis)
- Then: assess for LRTI vs URTI vs exacerbation of chronic disease
- Red flags: haemoptysis, dyspnoea, constitutional symptoms, risk factors
- CXR indicated if: RR >24, HR >100, Temp >38°C, signs of consolidation
Clinical algorithm for the evaluation and management of acute cough, including differentiation between life-threatening and non-life-threatening diagnoses, infectious causes (LRTI/URTI), exacerbations of pre-existing conditions, and red flag symptoms.
💎 CRB-65 — Risk Stratification in Primary Care
- CRB-65: Confusion, Respiratory rate ≥30, Blood pressure <90 systolic, Age ≥65
- Score 0: low risk — suitable for outpatient management
- Score 1–2: intermediate risk — consider hospital referral
- Score ≥3: high risk — urgent hospital admission
- Advantage over CURB-65: no blood test required — ideal for primary care
- Always supplement score with clinical judgement (social support, functional status)
CRB-65 scoring table for predicting mortality in community-acquired pneumonia, stratifying patients into low, moderate, and high risk groups with corresponding mortality rates and clinical disposition recommendations.
CAP — Empiric Antibiotic Therapy
- No comorbidities: Amoxicillin 1g TDS or Doxycycline 100mg BD
- With comorbidities (DM, chronic lung/heart/liver disease): Amoxicillin-clavulanate + macrolide or doxycycline; OR respiratory fluoroquinolone
- 💎 Macrolide monotherapy no longer recommended — high pneumococcal resistance
- Duration: minimum 5 days, guided by clinical stability
- Atypical coverage may be required — consider if no response to beta-lactam
Table of standard outpatient antibiotic regimens for community-acquired pneumonia, stratified by presence or absence of comorbidities and risk factors for MRSA or Pseudomonas aeruginosa, with detailed dosing footnotes.
Aspiration Pneumonia — Imaging & Management
- CXR/CT: look for dependent segment infiltrates — basal lobes (upright) or posterior upper lobes (supine)
- Cavitary lesions suggest anaerobic infection / lung abscess
- Treatment: amoxicillin-clavulanate (oral) or ampicillin-sulbactam (IV); minimum 5 days
- 🚨 Do NOT give glucocorticoids — antibiotics only
- Prevent recurrence: speech therapy, thickened feeds, oral hygiene, semi-recumbent positioning
- Advanced dementia: involve family in advance care planning — tube feeding may not improve QoL
Composite figure showing characteristic imaging findings in aspiration pneumonia: (A) PA chest radiograph with cavitary infiltrate in the left lower lobe, (B) bilateral lung infiltrates from recurrent aspiration, (C) CT scan showing right upper lobe posterior cavitary infiltrate, and (D) CT scan with new bilateral posterior gravity-dependent infiltrates post-aspiration.
💎 Key Summary
Key Point
Safety first: vital signs + ABC assessment before any investigation — refer emergencies immediately
Key Point
CRB-65 guides CAP disposition: score 0 = home, ≥1 = consider hospital
Key Point
Antibiotic stewardship: acute bronchitis and bronchiolitis are viral — antibiotics not indicated
Key Point
Vaccines prevent disease: influenza, pneumococcal, COVID-19 boosters for high-risk groups
Key Point
Nirsevimab (2025): single-dose RSV prophylaxis now approved in Singapore for all infants
Key Point
Aspiration pneumonia: think dysphagia risk factors, dependent infiltrates, multidisciplinary prevention
References
M113
Chronic Cough, Tuberculosis & Lung Cancer
Approach to Chronic Cough
- Chronic cough = cough lasting >8 weeks in adults (>4 weeks in children)
- Prevalence ~9.6% worldwide; significant quality-of-life impact
- Take a structured history: smoking, ACE inhibitors, recent URTI, wheezing, heartburn, occupational/environmental exposure
- Examine upper airways and ears — not just the chest
- Chest X-ray is the first-line investigation
- BTS 2023 algorithm guides systematic evaluation (see figure)
Clinical algorithm for the assessment and management of chronic cough (>8 weeks), including initial assessment, identification of red flags warranting urgent or 2-week-wait referral, evaluation for underlying disease and aggravants, and identification of treatable traits.
🚨 Chronic Cough in Children — Red Flags
- Chronic cough in children = >4 weeks duration; affects 5–10% of children in Singapore
- Key red flags: haemoptysis, digital clubbing, growth failure, hypoxia, choking episode
- Wet/productive cough suggests: protracted bacterial bronchitis (PBB), bronchiectasis, TB, aspiration
- PBB: wet cough ≥4 weeks responding to ≥2 weeks oral antibiotics (H. influenzae, S. pneumoniae, M. catarrhalis)
- Pertussis: catarrhal → paroxysmal (inspiratory whoop, post-tussive vomiting) → convalescent; treat with macrolides
- Counsel on Tdap booster for adolescents, adults, and healthcare workers (immunity wanes post-vaccination)
Table summarising key red flags in the history and physical examination of chronic cough in children, with corresponding possible aetiologies (e.g., haemoptysis, digital clubbing, choking, recurrent infections, auscultatory findings).
Hemoptysis — Evaluation Algorithm (Normal CXR)
Flowchart for the evaluation of haemoptysis when chest radiography findings are normal, stratified by cancer risk and history suggestive of lower respiratory tract infection, guiding observation, antibiotics, or CT imaging.
Lung Cancer — Local & Intrathoracic Manifestations
Table listing signs and symptoms of lung cancer due to local effects of the primary tumour (with likelihood ratios) and signs/symptoms of intrathoracic spread, including Pancoast tumour, Horner syndrome, and superior vena cava syndrome.
Lung Cancer — Distant Metastases and Paraneoplastic Syndromes
- Metastases can involve bone (pain, fractures), brain (headache, seizures), liver (jaundice, anorexia), adrenals, skin
- Paraneoplastic syndromes occur without direct tumour invasion:
- • Hypercalcaemia — ectopic PTHrP (NSCLC)
- • SIADH → hyponatraemia (SCLC)
- • Cushing syndrome — ectopic ACTH (SCLC)
- • Lambert-Eaton myasthenic syndrome — proximal weakness (SCLC)
- Digital clubbing more common with NSCLC
Table summarising signs and symptoms of lung cancer due to distant metastases by site (liver, bone, brain, lymphatics, adrenals, skin) with associated frequencies.
Lung Cancer — Paraneoplastic Syndromes (Detail)
Table of paraneoplastic syndromes associated with lung cancer, including frequency and clinical comments (e.g., hypercalcaemia, SIADH, Cushing syndrome, Lambert-Eaton myasthenic weakness, digital clubbing).
Key Summary
Key Point
Chronic Cough: >8 weeks adults, >4 weeks children. 'Big three' in non-smokers with normal CXR: UACS, Asthma, GERD. Use BTS 2023 algorithm.
Key Point
Haemoptysis: Rule out pseudohaemoptysis. Refer to ED if massive or haemodynamically unstable. Stratify by cancer risk if CXR normal.
Key Point
Pneumothorax: Tension = emergency. Needle decompression at 2nd ICS MCL or 4th/5th ICS AAL (ATLS 10th ed).
Key Point
TB: Incidence 28.9/100,000 in Singapore 2023. Notify TBCU within 72 hours. LTBI: rifampicin 4 months (preferred). Active TB: RIPE × 2 months then RI × 4 months. XDR-TB = WHO 2021 definition.
Key Point
Lung Cancer: NESFEA phenotype is high-risk. LDCT screening: 50–80 years, ≥20 pack-years (USPSTF 2021). SPN ≥8 mm → refer respiratory physician.
References
M114
Chronic Lung Diseases
Spirometry: Indications in Primary Care
- Confirming diagnosis of asthma, COPD, or other lung disease
- Monitoring disease progression and treatment response
- Pre-operative assessment and occupational health screening
- 💎 Spirometry is the gold standard — PEF monitoring is an alternative if unavailable but is less reliable
- Validity requires: ≥3 technically acceptable manoeuvres, two largest FVC and FEV₁ within 150 mL of each other
- Always perform post-bronchodilator testing when confirming COPD diagnosis
Example spirometry printout: FVC, FEV1, FEV1/FVC with flow-volume loops showing obstructive pattern
Lung Volumes & Capacities
- Tidal Volume (TV): Normal breathing (~500 mL at rest)
- Inspiratory Reserve Volume (IRV): Extra air inhaled beyond tidal breath
- Expiratory Reserve Volume (ERV): Extra air exhaled beyond tidal breath
- Residual Volume (RV): Air remaining after maximal exhalation — NOT measured by spirometry
- Functional Residual Capacity (FRC) = ERV + RV
- Total Lung Capacity (TLC) = VC + RV — requires body plethysmography
Diagram of lung volumes and capacities
Flow-Volume Loops: Normal vs Obstructive vs Restrictive
- Normal: smooth, triangular expiratory limb; symmetric inspiratory limb
- Obstructive: concave (scooped out) expiratory limb — classic in asthma and COPD
- Restrictive: preserved shape but reduced volumes (smaller loop)
- 💎 FEV₁/FVC < 0.70 (post-BD) = obstruction; FEV₁/FVC ≥ 0.70 with reduced FVC = restriction
- Variable intrathoracic obstruction (e.g., tracheomalacia): expiratory limb flattened
- Variable extrathoracic obstruction (e.g., vocal cord palsy): inspiratory limb flattened
Normal, obstructive, and restrictive flow-volume loop patterns
Spirometry Interpretation Algorithm
- Step 1: Assess FEV₁/FVC ratio — is it < 0.70 (LLN)?
- Step 2: If obstructive — perform bronchodilator reversibility test
- Step 3: If FEV₁/FVC ≥ 0.70 — check if FVC is reduced → restrictive pattern
- Step 4: Bronchodilator reversibility (≥12% and ≥200 mL FEV₁ increase) suggests asthma
- Step 5: Mixed pattern = obstruction + reduced FVC (e.g., severe COPD with air trapping)
- 💎 Always interpret in clinical context — spirometry alone does not make a diagnosis
Clinical algorithm for spirometry interpretation
Bronchiectasis: Overview
- Chronic irreversible airway dilatation from recurrent infection/inflammation
- Presents with: persistent productive cough, purulent sputum, recurrent exacerbations
- Common causes: post-infectious (TB, pertussis), immune deficiency, primary ciliary dyskinesia, CF
- 💎 Post-TB bronchiectasis is a major cause in Singapore and SE Asia
- Diagnosis: HRCT chest (shows dilated airways, 'signet ring' sign, mucus plugging)
- Key complication: haemoptysis — can be life-threatening
Treatable traits in bronchiectasis pathophysiology
Asthma Assessment: Control & Severity
- Two domains: (1) Symptom control over past 4 weeks; (2) Future risk of adverse outcomes
- Symptom control: daytime symptoms, night waking, activity limitation, reliever use
- 💎 Good symptom control does NOT mean no risk — lung function and exacerbation history must be assessed
- Severe asthma: uncontrolled despite high-dose ICS-LABA OR requiring it to stay controlled
- Before diagnosing severe asthma: exclude poor technique, poor adherence, wrong diagnosis, comorbidities
- Spirometry: at diagnosis, 3-6 months after starting treatment, then periodically
BREATHE mnemonic for asthma assessment (MOH Singapore)
Asthma Control Test (ACT)
- 5 questions covering activity limitation, shortness of breath, night symptoms, reliever use, overall control
- Scored 1-5 for each question (max 25)
- Score 20-25: Well-controlled asthma
- Score 16-19: Not well-controlled asthma — step up treatment
- Score 5-15: Very poorly controlled asthma — urgent review
- 💎 Use ACT at every follow-up as a standardized objective measure of control
Asthma Control Test (ACT) questionnaire
ICS Dose Equivalencies (GINA 2024)
- Low dose ICS: Budesonide 200-400 mcg/day; Beclometasone 200-500 mcg/day; Fluticasone propionate 100-250 mcg/day
- Medium dose: Budesonide 400-800 mcg/day; Beclometasone 500-1000 mcg; Fluticasone prop 250-500 mcg
- High dose: Budesonide >800 mcg/day; Beclometasone >1000 mcg; Fluticasone prop >500 mcg
- Children (6-11 yr): doses approximately halved; always use lowest effective dose
- Extrafine particle formulations (e.g., Qvar) achieve deeper lung deposition at lower doses
- 💎 Doubling the ICS dose for exacerbations has limited evidence; ICS-formoterol MART is preferred strategy
ICS dose equivalency table — adults/adolescents and children
GINA 2024: Two-Track Treatment Approach
- Track 1 (Preferred): As-needed low-dose ICS-formoterol as reliever AT ALL STEPS
- Track 2 (Alternative): As-needed SABA reliever + separate daily controller
- 🚨 SABA-only treatment (no ICS) is NO LONGER recommended — associated with increased exacerbation risk and death
- Track 1 advantage: every reliever puff delivers anti-inflammatory protection
- MART strategy: budesonide-formoterol OR beclometasone-formoterol for maintenance AND relief
- 💎 Track 1 reduces severe exacerbations by ~60-70% compared to SABA-only in clinical trials
GINA 2024 two-track initial asthma treatment flowchart
Stepwise Asthma Treatment (Adults ≥12 years)
- Step 1: As-needed low-dose ICS-formoterol (Track 1) OR low-dose ICS when SABA taken (Track 2)
- Step 2: As-needed low-dose ICS-formoterol (Track 1) OR daily low-dose ICS + as-needed SABA
- Step 3: Low-dose ICS-formoterol MART (Track 1) OR daily low-dose ICS-LABA + SABA
- Step 4: Medium-dose ICS-formoterol MART (Track 1) OR medium/high-dose ICS-LABA + SABA
- Step 5: High-dose ICS-LABA ± LAMA; investigate severe asthma; consider biologics
- 💎 Step up if uncontrolled for ≥3 months (after checking technique, adherence, triggers)
MOH Singapore ACE stepwise pharmacological treatment for asthma
GINA 2024 Management Cycle
- Cycle: Assess → Adjust treatment → Review response
- Assess: symptom control, risk factors, inhaler technique, adherence, comorbidities
- Adjust: step up or down based on response; address modifiable risk factors
- Review: 1-3 months after starting/changing treatment; 3-6 monthly in stable patients
- Non-pharmacological: smoking cessation, allergen avoidance, exercise, obesity management
- 💎 Personalise treatment — consider patient preferences, cost, device availability
GINA 2024 Assess-Start-Review management cycle
Written Asthma Action Plan (WAAP)
- Essential for all patients — reduces emergency visits and hospitalisations
- Three zones: Green (controlled), Yellow (worsening), Red (emergency)
- Green: continue regular medications as prescribed
- Yellow: increase reliever, start/increase preventer, consider OCS if not improving in 24-48h
- Red: call ambulance / go to A&E immediately if too breathless to speak
- 💎 Personalise to patient's medications; review and update at every visit
Written Asthma Action Plan (WAAP) example with traffic light zones
Preventer Medications in Singapore
- ICS alone: Budesonide (Pulmicort), Fluticasone propionate (Flixotide), Beclometasone (Qvar)
- ICS-LABA combinations: Budesonide-formoterol (Symbicort/Pulmicort Turbuhaler), Fluticasone-salmeterol (Seretide), Fluticasone-vilanterol (Relvar)
- LAMA add-on (Step 5): Tiotropium (Spiriva Respimat) — for adult asthma
- Biologics (severe asthma, Step 5): Omalizumab (anti-IgE), Dupilumab (anti-IL-4/13), Benralizumab (anti-IL-5Rα)
- LTRA: Montelukast — adjunct, less effective for exacerbation prevention than ICS
- 💎 For MART: Only budesonide-formoterol or beclometasone-formoterol are approved
Preventer medications for asthma registered in Singapore (MOH ACE 2020)
COPD: Diagnosis (GOLD 2024)
- ALL THREE required: (1) typical symptoms + (2) risk factor exposure + (3) spirometry confirmation
- Spirometry: Post-bronchodilator FEV₁/FVC < 0.70 confirms airflow obstruction
- Do NOT diagnose COPD without spirometry — clinical features alone are insufficient
- 💎 Spirometry is essential: many patients have 'silent' disease until spirometry reveals significant obstruction
- Exclude other diagnoses: asthma, cardiac failure, bronchiectasis, TB
- Screen proactively: any patient >35 years with smoking history AND symptoms
Spirometry in COPD: obstructive pattern (FEV1/FVC = 0.56)
GOLD ABE Classification (Current Standard)
- Replaced the old ABCD tool from 2023 — spirometry severity (GOLD 1-4) no longer drives initial therapy choice
- Group A: Low symptoms (mMRC 0-1 OR CAT <10) AND 0-1 moderate exacerbations (not hospitalised)
- Group B: High symptoms (mMRC ≥2 OR CAT ≥10) AND 0-1 moderate exacerbations
- Group E: ≥2 moderate exacerbations OR ≥1 severe exacerbation (hospitalisation in past year)
- 💎 Exacerbation history is the single best predictor of future exacerbations — ask at EVERY visit
- Still measure FEV₁ for grading severity (GOLD 1-4) and guiding some add-on therapy decisions
GOLD 2023+ ABE assessment framework
COPD Management Cycle
- Diagnose → Initial assessment (ABE group, symptoms, comorbidities) → Implement initial management
- Review: symptom control, exacerbation frequency, side effects, inhaler technique
- Adjust: escalate or de-escalate pharmacotherapy; add non-pharmacological interventions
- 💎 Reassess blood eosinophil count to guide ICS use — high eosinophils (≥300) favour ICS
- Check: inhaler technique and adherence at EVERY visit
- Address comorbidities: cardiovascular disease, depression, osteoporosis, lung cancer screening
GOLD COPD management cycle diagram
COPD: Initial Pharmacotherapy (GOLD ABE)
- Group A: ONE long-acting bronchodilator — LAMA (preferred) or LABA
- Group B: DUAL bronchodilator — LAMA + LABA (superior to monotherapy for symptom relief)
- Group E: LAMA + LABA; if eosinophils ≥300 cells/μL → start LAMA + LABA + ICS (triple therapy)
- 💎 ICS should NOT be used as initial monotherapy in COPD — only appropriate in triple therapy or ACO
- All patients: short-acting bronchodilator (SABA or SAMA) for breakthrough symptoms
- Reassess at 3 months for symptom response and exacerbation reduction
GOLD 2024 initial pharmacotherapy by ABE group
COPD: Follow-up Pharmacotherapy Algorithm
- Persistent DYSPNOEA on monotherapy → escalate to LAMA+LABA; if already on dual → check technique/switch
- Persistent EXACERBATIONS on LAMA+LABA: check blood eosinophils to guide next step
- Eosinophils ≥300: add ICS → triple therapy (LAMA+LABA+ICS)
- Eosinophils 100-300: consider adding ICS if still exacerbating
- Eosinophils <100: ICS unlikely effective; consider ROFLUMILAST (FEV₁ <50%, chronic bronchitis) or AZITHROMYCIN (ex-smokers)
- 💎 ICS overuse increases risk of pneumonia in COPD — reserve for those with high eosinophils or frequent exacerbations
COPD follow-up pharmacotherapy algorithm — dyspnoea vs exacerbation pathway
COPD: Non-Pharmacological Management
- 🚨 SMOKING CESSATION: single most effective intervention — slows FEV₁ decline, reduces mortality
- Vaccinations: Influenza (annual), Pneumococcal (PCV20 or PCV13+PPSV23), COVID-19, Tdap, RSV
- Pulmonary Rehabilitation (PR): essential for Group B and E — improves dyspnoea, exercise capacity, QoL
- Physical Activity: encourage daily walking; even moderate activity improves outcomes
- Long-Term Oxygen Therapy (LTOT): indicated if PaO₂ ≤55 mmHg or SaO₂ ≤88% at rest — improves survival
- 💎 Palliative care referral early: severe COPD has a poor prognosis; advance care planning is essential
Non-pharmacological COPD management by patient group (GOLD 2024)
🚨 COPD Exacerbations: Classification & Management
- Mild: treat with SABDs (SABA ± SAMA) alone; no antibiotic or OCS required
- Moderate: SABDs + antibiotics AND/OR oral corticosteroids (prednisolone 40 mg × 5 days)
- Severe: hospitalisation required; IV bronchodilators, controlled oxygen (SpO₂ 88-92%), NIV
- Antibiotics indicated if: increased dyspnoea + increased sputum volume + increased purulence (all 3 cardinal signs)
- 🚨 NIV is first-line for hypercapnic respiratory failure in COPD — reduces intubation and mortality
- 💎 Post-exacerbation: review within 4 weeks; optimise maintenance therapy; cardiac cause?
COPD exacerbation severity algorithm and differential diagnosis
Singapore MOH ACE: COPD Diagnosis (2024)
- Suspect COPD: any patient ≥40 years with dyspnoea, chronic cough/sputum, and risk factor exposure
- Confirm with post-bronchodilator spirometry: FEV₁/FVC < 0.70
- Assess: symptoms (CAT/mMRC), exacerbation history, blood eosinophil count
- Exclude: asthma, cardiac failure, bronchiectasis, TB
- Refer if: uncertain diagnosis, rapid decline, severe disease (FEV₁ <30%), suspected lung cancer
- 💎 Many COPD patients in Singapore are underdiagnosed — proactive case-finding in at-risk individuals is recommended
Singapore MOH ACE COPD diagnostic algorithm (June 2024)
Singapore MOH ACE: COPD Management (2024)
- Strong recommendation: smoking cessation counselling at every visit
- Dual LABD (LAMA+LABA) preferred for patients with significant symptoms or exacerbation risk
- Triple therapy (LAMA+LABA+ICS) for frequent exacerbators with eosinophils ≥300 cells/μL
- Assess inhaler technique and adherence at every visit — use the 'show me how' approach
- Refer for pulmonary rehabilitation: for Group B and E patients
- 💎 ICS de-escalation: consider withdrawing ICS if eosinophils <100 and not exacerbating — reduces pneumonia risk
Singapore MOH ACE COPD management flowchart (June 2024)
Interstitial Lung Disease (ILD): Overview
- Large, heterogeneous group of conditions — inflammation and/or fibrosis of lung interstitium
- Impaired gas exchange → progressive dyspnoea, dry cough, fatigue, chest discomfort
- Restrictive physiology on PFTs: reduced TLC, FVC; normal or elevated FEV₁/FVC ratio
- Key categories: idiopathic (IPF), autoimmune-related, exposure-related, sarcoidosis, others
- Epidemiology: IPF incidence increasing; prognosis poor (median survival ~3-5 years from diagnosis)
- 💎 ILD is often underdiagnosed — progressive unexplained dyspnoea with bibasilar crackles should prompt investigation
Classification of interstitial lung diseases
IPF: Pathophysiology
- Idiopathic Pulmonary Fibrosis (IPF): most common idiopathic IIP; progressive, irreversible fibrosis
- Repeated microinjuries to alveolar epithelium → abnormal wound healing → fibroblast activation → fibrosis
- Gross: honeycombing (subpleural, basal-predominant) on HRCT
- Loss of gas exchange surface → hypoxaemia, especially on exertion
- Risk factors: male sex, older age (>60), cigarette smoking, environmental exposures
- 💎 IPF has no truly effective cure — anti-fibrotics slow progression but do not reverse fibrosis
Healthy lung vs IPF: alveolar fibrosis and gas exchange impairment
ILD: HRCT Patterns
- UIP (Usual Interstitial Pneumonia): subpleural, basal honeycombing ± traction bronchiectasis → IPF
- NSIP (Non-Specific Interstitial Pneumonia): bilateral ground glass ± reticulation; autoimmune-related
- Hypersensitivity Pneumonitis: centrilobular nodules, ground glass, mosaic attenuation
- Sarcoidosis: perilymphatic nodules, hilar/mediastinal lymphadenopathy
- Organising Pneumonia: consolidation, often peribronchial or subpleural — can mimic pneumonia
- 💎 HRCT pattern guides MDT diagnosis and determines management approach
CT patterns in ILDs: IPF, NSIP, HP, sarcoidosis, organising pneumonia
Key Summary: Spirometry & Bronchiectasis
Key Point
💎 Spirometry is essential for diagnosing and monitoring obstructive and restrictive lung disease
Key Point
FEV₁/FVC <0.70 (post-BD) = obstruction; reduced FVC with normal ratio = restriction
Key Point
Positive BD reversibility (≥12% + ≥200 mL) suggests asthma but does not exclude COPD
Key Point
Bronchiectasis: irreversible airway dilatation; manage with airway clearance, macrolides, vaccinations
Key Point
Post-TB lung disease is a major cause of morbidity in Singapore — proactive management needed
Key Point
Spirometry is indicated for any patient with unexplained dyspnoea, chronic cough, or respiratory risk factors
Key Summary: Asthma
Key Point
Diagnosis requires BOTH variable symptoms AND confirmed variable airflow limitation — do not treat empirically without evidence
Key Point
💎 GINA 2024 strongly prefers Track 1: ICS-formoterol as reliever at ALL steps — reduces severe exacerbations by ~60-70%
Key Point
🚨 SABA-only treatment is no longer recommended — every patient should have an ICS-containing controller
Key Point
MART (budesonide-formoterol or beclometasone-formoterol): maintenance AND reliever in one inhaler
Key Point
Check inhaler technique and adherence at EVERY visit — poor technique is the most common cause of poor control
Key Point
All patients should have a Written Asthma Action Plan (WAAP)
Key Summary: COPD
Key Point
Diagnosis requires symptoms + risk factor exposure + post-BD FEV₁/FVC <0.70 — never diagnose without spirometry
Key Point
GOLD ABE framework (not ABCD): Group A → 1 LABD; Group B → LAMA+LABA; Group E → LAMA+LABA ± ICS
Key Point
Blood eosinophil count guides ICS use: ≥300 → add ICS; <100 → ICS unlikely effective
Key Point
💎 Smoking cessation is the MOST effective intervention — reduces FEV₁ decline rate
Key Point
Vaccinations, pulmonary rehabilitation, and physical activity are essential non-pharmacological pillars
Key Point
🚨 COPD exacerbation: SABDs + OCS (5 days) + antibiotics if all 3 cardinal signs present
Key Summary: ILD
Key Point
Suspect ILD in: progressive exertional dyspnoea + dry cough + bibasilar velcro crackles
Key Point
Restrictive spirometry + reduced DLCO → refer for HRCT and respiratory specialist MDT evaluation
Key Point
💎 Do NOT start empirical treatment in primary care — accurate diagnosis via MDT is essential
Key Point
IPF: anti-fibrotics (pirfenidone/nintedanib) slow progression; no cure
Key Point
Connective tissue disease-ILD: immunosuppression; Hypersensitivity pneumonitis: remove causative antigen
Key Point
Integrate palliative care early — progressive ILD has significant symptom burden and poor prognosis
References
M121
Ear Conditions
Normal Tympanic Membrane — The Baseline
- Landmark: cone of light (anterior-inferior), handle of malleus, pars tensa and pars flaccida
- Normal TM: pearlescent/grey, intact, mobile on pneumatoscopy
- Any deviation from this baseline is clinically significant
- Always examine both ears; compare sides
- A confident normal finding is as important as detecting pathology
Normal tympanic membrane with visible light reflex and handle of malleus
Otitis Externa — Clinical Features
- Pain constant, worsened by tragal pressure or pinna traction
- Creamy/white discharge; canal erythematous, oedematous, with debris
- TM usually intact and normal
- Risk factors: water exposure, instrumentation, skin conditions
- Chronic OE: thick, malodorous discharge with desquamated skin
External ear showing erythema, scaling, and moist debris — otitis externa
Dermatitis of the Ear Canal
- Consider when OE does not respond after 1 week of treatment
- Causes: otic medications, cosmetics, earplugs, shampoos, hearing aid moulds
- Classic: shiny, erythematous canal extending to the conchal bowl
- Manage by identifying and removing the irritant
- Topical steroid cream may help; avoid prolonged use
External ear showing mild erythema and scaling of conchal bowl — early otitis externa or eczema
Otomycosis — Fungal Otitis Externa
- ~9% of otitis externa cases; more common after antibiotic eardrops
- Predominant symptom: intense itch (more than in bacterial OE)
- Candida spp.: white fungal ball in canal
- Aspergillus spp.: black spore heads on canal wall or TM
Otoscopic view showing white fungal mass consistent with otomycosis (Aspergillus or Candida)
💎 Aspergillus Niger Otomycosis — Classic Appearance
- Black spore heads on tympanic membrane or canal wall — pathognomonic
- Do NOT confuse with a foreign body
- Treatment: thorough aural toileting + clotrimazole 1% drops or solution
- Avoid prolonged antibiotic drops — predisposes to fungal superinfection
- Local Singapore study: 38% of community OE patients had positive fungal culture
Otoscopic view of Aspergillus niger otomycosis with characteristic black spore heads on tympanic membrane
Acute Suppurative Otitis Media — Recognition
- Classic history: severe otalgia → sudden painless yellowish discharge (perforation)
- Otoscopy before perforation: red, bulging, opaque TM — loss of light reflex
- After perforation: pulsatile discharge; pain relieves
- Central/tubo-tympanic perforations = 'safe'; marginal/attic = 'unsafe' (cholesteatoma risk)
- Most perforations heal within weeks; refer to ENT if persists >3 months
Otoscopic view showing bulging, opaque tympanic membrane with middle ear effusion — acute otitis media
Cholesteatoma — Do Not Miss
- Keratinized squamous epithelium in middle ear/mastoid — erodes bone
- Key features: persistent foul-smelling otorrhoea, marginal or attic perforation
- May cause: facial nerve palsy, SNHL, intracranial complications
- Can be congenital or acquired (secondary to retraction pocket)
- 🚨 Mandatory ENT referral — surgical treatment required
Otoscopic view showing cholesteatoma with keratin debris and retraction pocket in the tympanic membrane
OME and Tympanosclerosis — Differentiating TM Appearances
- OME: dull, retracted TM; bluish hue, air-fluid level, or bubbles visible
- OME does NOT cause discharge unless it evolves into AOM
- 🚨 Unilateral OME in adults → urgent ENT referral to exclude NPC
- Tympanosclerosis: chalky white plaques on TM; does NOT cause discharge
- Tympanosclerosis: history of grommet insertion; rarely causes conductive hearing loss
Otitis media with effusion — bluish tympanic membrane with air-fluid level
Tympanosclerosis
- Chalky white calcified plaques on the tympanic membrane
- Result of prior inflammation — common after grommet insertion
- Does NOT cause ear discharge
- Usually clinically insignificant; rarely involves ossicles causing conductive HL
- Reassure the patient — no treatment required unless symptomatic
Tympanosclerosis — white calcified plaques on tympanic membrane