Pulmonologist Role in Diagnosis and Management
Yes, a pulmonologist is the appropriate specialist to diagnose and manage both upper airway cough syndrome (UACS) and non-asthmatic eosinophilic bronchitis (NAEB), particularly when the patient responds to corticosteroids, as this suggests eosinophilic airway inflammation requiring specialized respiratory evaluation and treatment. 1, 2
Diagnostic Approach by Pulmonology
A pulmonologist will establish the diagnosis through:
- Spirometry with normal results (no airflow obstruction) and absence of airway hyperresponsiveness on bronchial challenge testing (e.g., methacholine) to distinguish NAEB from asthma 1, 2
- Sputum induction or bronchoscopy with bronchial wash to document airway eosinophilia, which is the gold standard for confirming NAEB 2, 3
- Non-invasive biomarkers including fractional exhaled nitric oxide (FeNO) and blood eosinophil counts to support the presence of eosinophilic inflammation 1, 4
- Chest radiography to exclude other pulmonary pathology 5, 4
The key diagnostic criteria for NAEB include: normal chest radiograph, normal spirometry, no variable airflow obstruction or airway hyperresponsiveness, presence of airway eosinophilia, and improvement with corticosteroid therapy 2.
Treatment Management by Pulmonology
First-Line Therapy
Inhaled corticosteroids (ICS) are the recommended first-line treatment for NAEB 1, 2. The CHEST guidelines specifically recommend ICS as first-choice treatment for chronic cough due to NAEB, though the evidence base includes small numbers of subjects 1.
Escalation Strategy
If response to initial ICS is incomplete, the pulmonologist should:
- Step up the inhaled corticosteroid dose after reconsidering alternative causes of cough 1, 2
- Add a leukotriene receptor antagonist as a therapeutic trial 1, 2
- Consider oral corticosteroids if symptoms remain persistently troublesome despite high-dose ICS or if the natural history of eosinophilic airway inflammation progresses 2
The patient's positive response to oral and systemic steroids during flares supports the diagnosis of NAEB and validates this treatment approach 2.
Distinguishing UACS from NAEB
Critical Diagnostic Nuance
Upper airway cough syndrome with latent eosinophilic bronchitis is a distinct entity where sputum eosinophilia (3.5-8.0%) may be present but is not the primary driver of cough 6. In these cases:
- Cough resolves with oral antihistamines alone within 2-5 weeks 6
- Sputum eosinophil percentage does not change significantly after successful treatment 6
- This recognition avoids unnecessary corticosteroid use 6
However, if the patient requires corticosteroids for symptom control (as in your case), this strongly suggests NAEB rather than UACS with incidental eosinophilia 6.
Common Pitfalls to Avoid
- Do not assume UACS is the primary diagnosis simply because rhinitis symptoms are present; eosinophilic airway inflammation can coexist with multiple conditions 7, 6
- Treatment duration matters: shorter treatment courses correlate with higher relapse rates in NAEB 3
- Reassess sputum eosinophils after treatment to identify patients at risk of relapse 8, 3
- Consider occupational or environmental triggers as potential causes of NAEB that may require avoidance rather than chronic corticosteroid therapy 2
Prognosis and Long-Term Management
NAEB is primarily a chronic disease with high relapse rates after treatment 8, 3. Long-term follow-up studies suggest NAEB is a distinct entity rather than an early stage of asthma or COPD 8. The pulmonologist will need to establish a long-term monitoring plan with periodic reassessment of eosinophilic inflammation 8, 3.