What is asthma with bronchitis?

"Asthma with Bronchitis" - Understanding the Clinical Overlap

"Asthma with bronchitis" is not a formal medical diagnosis but rather describes a clinical scenario where patients present with features of both conditions—either acute bronchitis triggering asthma symptoms, or more commonly, undiagnosed asthma being misidentified as recurrent bronchitis. This distinction is critical because the two conditions require fundamentally different management approaches.

The Diagnostic Challenge

The most important clinical reality is that asthma is frequently misdiagnosed as acute bronchitis—occurring in approximately one-third of patients presenting with acute cough. 1 This misdiagnosis has significant implications:

• In patients with at least two similar physician-diagnosed episodes of "acute bronchitis" in the past 5 years, 65% actually have mild asthma. 1 This represents a critical diagnostic pitfall where recurrent respiratory symptoms are incorrectly attributed to repeated infections rather than underlying chronic airway disease.

• The clinical pictures of acute bronchitis and asthma exacerbations are frequently quite similar, making differentiation challenging without prospective evaluation to determine whether the episode is isolated or part of a chronic disease pattern. 1

Key Distinguishing Features

Acute Bronchitis (True)

• Cough lasting less than 3 weeks, with or without sputum production 1
• Should only be diagnosed after excluding pneumonia, common cold, acute asthma, and COPD exacerbation 1
• Transient bronchial hyperresponsiveness may occur but typically resolves within 2-3 weeks (occasionally up to 2 months) 1
• Self-limited course without recurrence 1

Asthma Masquerading as Bronchitis

• Recurrent episodes of "bronchitis" are the hallmark—if a patient has had multiple similar episodes, asthma must be strongly considered. 1
• Cough that worsens at night or after exposure to cold or exercise suggests cough-variant asthma 1
• Variable airflow obstruction and airway hyperresponsiveness are present (though may not be evident during acute presentation) 1
• Female sex, current wheeze, episodes of dyspnea over the past year, and symptoms triggered by allergens increase likelihood of underlying asthma 2

The Temporal Diagnostic Algorithm

For acute cough (<2-3 weeks duration): Distinguishing asthma from acute bronchitis is difficult because many patients with acute bronchitis develop transient bronchial hyperresponsiveness and abnormal spirometry. 1 Therefore, evaluation for chronic asthma should be limited to patients with cough lasting longer than 3 weeks. 1

For persistent cough (>3 weeks): Other diagnoses must be considered including cough-variant asthma, upper airway cough syndrome, gastroesophageal reflux disease, and nonasthmatic eosinophilic bronchitis. 1

For recurrent episodes: The only reliable diagnostic approach is prospective longitudinal evaluation to determine whether episodes represent isolated infections or a pattern consistent with chronic airway disease like asthma. 1

Nonasthmatic Eosinophilic Bronchitis - A Related Entity

Nonasthmatic eosinophilic bronchitis represents a distinct condition that shares eosinophilic airway inflammation with asthma but lacks variable airflow obstruction and airway hyperresponsiveness. 1 This accounts for 10-30% of chronic cough cases. 1

Key differentiating features from asthma:

• Normal airway responsiveness (methacholine challenge >16 mg/mL) 1
• Sputum eosinophilia ≥3% (similar to asthma) 1
• Mast cells infiltrate the epithelium rather than airway smooth muscle (as occurs in asthma) 1
• Responds to inhaled corticosteroids like asthma 1

Critical Clinical Pitfalls

Do not assume purulent sputum indicates bacterial infection requiring antibiotics—purulence results from inflammatory cells and can occur with viral or bacterial infections. 1 The color of sputum does not reliably predict bacterial etiology.

Do not continue labeling recurrent episodes as "acute bronchitis"—this pattern strongly suggests underlying asthma that requires controller therapy rather than episodic treatment. 1

Do not miss the opportunity for early asthma diagnosis—the initial clinical evaluation is crucial in longitudinal care, as retrospective studies show 65% of recurrent "bronchitis" episodes represent mild asthma. 1

Management Implications

For true acute bronchitis: Routine antibiotics, antivirals, antitussives, inhaled beta agonists, inhaled anticholinergics, inhaled corticosteroids, oral corticosteroids, and oral NSAIDs are not recommended until proven safe and effective. 1

For suspected underlying asthma: Bronchodilator response or positive methacholine challenge confirms the diagnosis, and controller therapy with inhaled corticosteroids is indicated. 1 Bronchodilators should be used on demand with anti-inflammatory treatment rather than continuously without anti-inflammatory therapy. 3

For nonasthmatic eosinophilic bronchitis: Inhaled corticosteroids are the treatment of choice, with dose and duration varying between patients. 1