Chronic cough lasting more than eight weeks is often attributed to common conditions such as asthma, allergic rhinitis, or gastroesophageal reflux.
However, in a significant subset of patients, especially those with daily sputum production, the underlying culprit is bronchiectasis—frequently overlooked and under-diagnosed.
According to Dr. James Chalmers, "Up to 50% of patients with daily cough and sputum have undetected structural airway abnormalities consistent with bronchiectasis, yet most remain misclassified under chronic bronchitis or post-infectious cough."
Structural Airway Distortion: Beyond Radiologic Curiosity
Bronchiectasis involves irreversible dilatation and architectural damage of the bronchial lumen due to recurrent inflammation and infection. High-resolution computed tomography (HRCT) is the gold standard for detection. In clinical practice, the disease is increasingly recognized in patients without classical risk factors, including non-smokers and those without a history of pulmonary infections.
Recent data report that over 40% of idiopathic cases show no clear etiology, challenging previous assumptions about causation.
Daily Mucopurulent Sputum: A Clinical Marker Often Downplayed
Patients with bronchiectasis frequently produce thick, purulent sputum daily, particularly in the morning. Repeated detection of certain bacteria like Pseudomonas aeruginosa in sputum samples may signal a more severe form of the disease, linked to faster decline in lung function and a higher risk of hospitalization.
If persistent bacterial colonization is not properly managed, it can trigger repeated flare-ups, worsen airflow obstruction, and promote systemic inflammation. This highlights the importance of early detection and the use of targeted antibiotic treatments to improve long-term health outcomes.
Systemic Inflammation and Comorbid Burden
Bronchiectasis is not a localized airway issue. Systemic inflammatory markers such as CRP, IL-8, and fibrinogen are often elevated, indicating broader immunologic activation. Coexisting diseases particularly rheumatoid arthritis, COPD, and non-tuberculous mycobacterial (NTM) infections are frequently seen, complicating diagnosis and treatment algorithms.
Exacerbations Mislabelled as Recurrent Chest Infections
Recurrent respiratory tract infections in patients with bronchiectasis are often mistaken for isolated acute bronchitis. However, each flare-up potentially worsens airway inflammation and leads to further structural decline. Patients experiencing more than two exacerbations per year are considered high-risk and may benefit from prophylactic macrolide therapy or inhaled antibiotics.
Dr. Francesco Blasi explains, "What appears to be recurrent bronchitis might, in fact, be a phenotype of chronic infection in a distorted airway. The earlier we intervene, the better the functional preservation."
Diagnostic Delay: A Gap in Primary and Secondary Care
Despite available imaging and sputum diagnostics, the average delay from symptom onset to diagnosis remains over two years in many countries. General practitioners often lack awareness, and even pulmonologists may miss atypical presentations. A clinical scoring system, can aid in early recognition and management stratification.
Bronchiectasis challenges the conventional paradigm of chronic cough etiology. A nuanced approach, incorporating imaging, microbiology, and systemic inflammation markers, is essential for timely recognition and effective treatment. By shifting clinical attention to this neglected diagnosis, outcomes for a growing but silent patient population can improve significantly.
