Chronic Cough — SAQ

Stem

A 49-year-old female non-smoker who works as a teacher presents to her GP with a dry, irritating cough that has been present continuously for the past 12 weeks. It is worse at night, on talking, in cold air, and after meals. She describes throat clearing, a sensation of mucus dripping down the back of her throat, and intermittent heartburn. She is overweight (BMI 31). She has hypertension treated with ramipril 10 mg daily (started 4 months ago) and mild allergic rhinitis. She does not smoke and takes no other medications. Examination of the chest, ENT and cardiovascular systems is normal. Spirometry in the surgery shows FEV1/FVC 0.78 (predicted 0.80) with no bronchodilator reversibility.

Questions

a) Define chronic cough and list the five red flags that demand urgent investigation rather than empirical therapy. (2 marks)

Chronic cough = a cough lasting more than 8 weeks in an adult. Red flags:

1. Haemoptysis
2. Weight loss (or other systemic features — fever, night sweats)
3. Smoker over 50 / new or changing chronic cough
4. Abnormal chest X-ray
5. Significant dyspnoea, hoarseness over 3 weeks, or swallowing difficulty

b) Apply the ERS 2020 diagnostic algorithm to THIS patient. What are her likely contributing causes and what is your immediate management? (4 marks)

Step 1 — all patients get a chest X-ray to exclude serious disease (cancer, TB, ILD, heart failure). If normal:

Step 2 — review and remove iatrogenic/smoking triggers. This patient is on ramipril (an ACE inhibitor), which causes cough in up to 15 percent through bradykinin/substance-P accumulation sensitising airway C-fibres. STOP ramipril and substitute an ARB (e.g., losartan 50 mg daily); the cough typically resolves within 1 to 4 weeks.

Step 3 — she has features of all three 'big three' common causes simultaneously (overlap is common):

• UACS — post-nasal drip, throat clearing, allergic rhinitis → intranasal corticosteroid (mometasone 50 mcg, 2 sprays each nostril daily) plus oral non-sedating antihistamine.
• Asthma / eosinophilic bronchitis — nocturnal, cold-air/talking triggered; spirometry here is borderline but check FeNO (50 ppb or more supports eosinophilic airway inflammation) → trial inhaled corticosteroid (budesonide 400 mcg twice daily or fluticasone 250 mcg twice daily) for 4 weeks.
• GORD — worse after meals, overweight, heartburn → PPI (omeprazole 20 to 40 mg once daily) plus lifestyle (weight loss, elevate head of bed, avoid late meals/alcohol/coffee) for at least 8 weeks.

Step 4 — treat causes sequentially, re-assessing response before declaring failure.

c) Six months later the cough persists despite full, adherent empirical therapy for all three causes, ACE-inhibitor cessation and a normal high-resolution CT. What is the diagnosis and outline the management ladder for this condition? (4 marks)

Diagnosis: refractory chronic cough (RCC) — cough that persists despite optimal treatment of all identifiable causes, reflecting cough-reflex hypersensitivity (peripheral and central sensitisation of vagal afferents lowering the cough threshold). Refer to a specialist cough clinic. Management ladder:

1. Speech-language pathology (SLP) therapy / cough-suppression physiotherapy — education, vocal hygiene, controlled breathing, cough suppression; RCT-supported first-line.
2. Neuromodulators (evidence: Ryan et al., Lancet 2012):
   • Gabapentin titrated to a maximum of 1800 mg/day in divided doses over 2 weeks, continued for up to 10 weeks; main adverse effects somnolence and dizziness.
   • Pregabalin 75 to 300 mg/day as an alternative.
   • Low-dose slow-release morphine 5 to 10 mg twice daily for short courses in selected patients.
3. P2X3 antagonist (gepapixant 45 to 90 mg twice daily) where licensed — blocks ATP-mediated afferent signalling; main adverse effect is taste disturbance (dysgeusia).
4. Avoid long-term codeine/dextromethorphan — limited efficacy, dependence/sedation.
5. Address comorbid anxiety/depression and the complications (urinary incontinence, sleep disturbance, cough syncope).