1. Asthma

📄Definition

Chronic inflammatory airway disease with:

  • Reversible airflow obstruction

  • Airway hyperresponsiveness

  • Often linked to atopy and environmental triggers

Mnemonic: AIR

Airway inflammation
Intermittent symptoms
Reversible obstruction

🧬 Pathophysiology

  • Trigger (allergen, infection, exercise, cold air) → immune activation

  • Mast cells → histamine, leukotrienes → bronchial smooth muscle contraction

  • Eosinophils (IL-5 driven) → airway inflammation

  • Mucosal oedema + mucus hypersecretion → narrowed airways

🛡️ Risk Factors (Mnemonic: ASTHMIC)

  • Atopy (eczema, hay fever)

  • Smoking (active/passive)

  • Triggers (cold, dust, pets, pollen)

  • Household irritants (mould, damp)

  • Medications (NSAIDs, β-blockers)

  • Infections (esp. viral in childhood)

  • Childhood/family history

🤒 Symptoms (Mnemonic: WHACK)

  • Wheeze (expiratory, polyphonic)

  • Heavy chest (tightness)

  • At night/early morning (worse)

  • Cough (often dry, variable)

  • Keen trigger sensitivity (exercise, pets, dust, cold)

Symptoms are episodic and worse on exertion or allergen exposure.

🚩 Red Flags / Severe Features

  • Silent chest, exhaustion, confusion → impending respiratory failure

  • Life-threatening asthma: SpO₂ <92%, PEF <33%, silent chest, cyanosis, arrhythmia, hypotension

  • Near-fatal asthma: Raised PaCO₂ or need for mechanical ventilation

🔬 Investigations 

TestUseExam Notes
Spirometry with reversibilityObstructive pattern (FEV₁/FVC <70%) + ≥12% & ≥200 ml ↑ FEV₁ post-bronchodilatorDiagnostic gold standard
Peak flow monitoringVariability >20% = diagnosticDiurnal variation: morning dipping worse
FeNORaised in eosinophilic inflammationNICE recommends in uncertain cases
Allergy testingRAST/skin prick if atopy suspectedNot first-line
BloodsMay show eosinophiliaRule out differentials
CXRIf atypical / to exclude pneumoniaOften normal in asthma

🩻 CXR Findings (Mnemonic: THUMP)

  • Thickened bronchial walls

  • Hyperinflated lungs (flattened diaphragms)

  • Unusual findings suggest another cause

  • Mediastinal shift (if tension pneumothorax)

  • Pneumothorax / pneumomediastinum

📊 Severity of Acute Asthma (BTS/NICE)

ClassificationFeatures
ModeratePEFR 50–75%, speaks in full sentences
SeverePEFR 33–50%, RR >25, HR >110, can’t finish sentences
Life-threateningPEFR <33%, SpO₂ <92%, silent chest, cyanosis, confusion, hypotension

Stepwise Management (NICE 2022 Update)

Key Shift: MART Preferred

MART (Maintenance and Reliever Therapy) is now first-line for many adults and young people using:

  • Low-dose ICS-formoterol as both daily preventer and reliever
    (e.g. Fostair, Symbicort)

Mnemonic: SMART PLAN
SABA no longer routinely used if on MART
MART preferred for many (ICS-formoterol)
Add-on therapy if uncontrolled: LTRA, ↑ICS
Review inhaler technique and adherence
Tailor plan to patient age and symptom pattern
Personalised asthma action plan
Low-dose ICS if not suitable for MART
Adult vs child algorithms differ
NICE stepwise diagram guides escalation

📋 Stepwise Treatment Ladder

StepTreatmentNotes
1MART (low-dose ICS–formoterol) daily + PRNPreferred adult first-line
2Increase ICS dose or add LTRA (montelukast)Watch behavioural SE
3Switch to alternative inhaler regimen or ↑ICSSpecialist review if uncontrolled
Children <5SABA trial → daily ICS if frequentMART not licensed

Offer a structured review to people with asthma at least annually.
More frequent reviews may be needed after treatment changes or exacerbations.

🚨 Acute Asthma Management (Mnemonic: O SHIT ME)

Oxygen (aim SpO₂ 94–98%)
Salbutamol (neb or inhaler)
Hydrocortisone IV / Prednisolone PO
Ipratropium (neb, esp. in severe)
Theophylline (specialist input only)
Magnesium sulfate IV (for life-threatening cases)
Escalate care → HDU/ICU if deteriorating

Monitoring & Review

  • Annual asthma review

  • Personalised Asthma Action Plan (PAAP)

  • Check inhaler technique and trigger control

  • Consider stepping down therapy if controlled for ≥3 months

⚠️ Complications

Mnemonic: RAMP
Respiratory failure
Air leaks – pneumothorax or pneumomediastinum
Mucus plugging
Persistent hypoxaemia

❓ Differential Diagnoses (Mnemonic: VACUUM)

  • Vocal cord dysfunction

  • Anaphylaxis

  • COPD

  • Upper airway obstruction

  • Undiagnosed cardiac disease (HF)

  • MSK chest pain

🔎 Key PARA Exam Traps

  • Reversibility (≥12% & ≥200 ml FEV₁) = asthma; irreversible = COPD

  • Life-threatening asthma signs: silent chest, PEF <33%, SpO₂ <92%

  • Near-fatal = raised PaCO₂ or ventilation

  • Always give O₂ with neb salbutamol (not air)

  • ICS started early (≥3 SABA uses/week)

  • Montelukast → behavioural SEs

  • ICS inhalers → rinse mouth to prevent oral candidiasis

  • Only adults use MART

  • Cardioselective β-blockers (bisoprolol) may be safe but exam trap

📅 Last updated in line with:

  • NICE NG80 (Asthma: diagnosis, monitoring and chronic management) – Nov 2022

  • BTS/SIGN Asthma Guideline – 2019

  • PARA-aligned, reviewed July 2025

PASSMAP ensures all content is NICE-aligned and exam-optimised for the Physician Associate Regulation Assessment (PARA).

Scroll to Top