What is the appropriate treatment for a patient with a cough and radiographic findings of prominent lung markings, mild peribronchial thickening, and a slightly elevated left hemidiaphragm?

Management of Cough with Prominent Lung Markings and Peribronchial Thickening

Begin with empiric treatment for the most common causes of chronic cough—upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD)—rather than rushing to advanced imaging, as these radiographic findings likely represent age-related changes or early bronchial disease that will respond to standard therapy. 1, 2

Initial Therapeutic Approach

The radiographic findings of prominent lung markings with mild peribronchial thickening do not indicate a specific diagnosis requiring immediate intervention. Instead, follow a systematic empiric treatment algorithm:

First-Line Treatment: UACS

• Start with a first-generation antihistamine-decongestant combination as the initial diagnostic/therapeutic trial 1
• Expect noticeable improvement within days to 1-2 weeks, with complete resolution potentially taking several weeks to months 1
• If partial resolution occurs, UACS is confirmed as at least one contributing factor 1

Second-Line: Evaluate for Asthma

• If UACS treatment provides only partial relief or no improvement, proceed to evaluate for asthma (including cough-variant asthma) 1, 3
• Consider bronchoprovocation testing if baseline pulmonary function tests are normal 4
• Treat empirically with inhaled corticosteroids and bronchodilators if asthma is suspected 5

Third-Line: Address GERD

• If cough persists despite treatment of UACS and asthma, initiate empiric therapy for GERD 1, 2
• Multiple causes frequently coexist—do not stop treating one condition when adding another 1

Clinical Context of Radiographic Findings

The chest X-ray findings described warrant specific interpretation:

• Prominent lung markings and peribronchial thickening may represent early bronchiectasis, chronic bronchitis, or age-related changes rather than acute pathology 1, 2
• Up to 20% of patients over 70 years have bronchiectasis on imaging, with 57% being asymptomatic 2
• These findings are common in elderly patients even without respiratory symptoms 2
• The slightly elevated left hemidiaphragm is typically an incidental finding unrelated to the cough unless there are other concerning features 2

When to Escalate to Advanced Imaging

Proceed to high-resolution CT (HRCT) chest only if empiric treatment fails after adequate trials of therapy for common causes: 1, 6

• HRCT detects bronchiectasis missed in 34% of cases with "normal" or minimally abnormal chest radiographs 1, 7
• CT identifies clinically significant findings in 27-28% of patients with chronic cough and unremarkable radiographs, most commonly bronchiectasis and bronchial wall thickening 1, 6
• However, wide application of CT in all chronic cough patients has low clinical yield when used before empiric treatment 6

Red Flags Requiring Immediate CT or Bronchoscopy

Bypass empiric treatment and proceed directly to advanced evaluation if any of the following are present: 6, 7

• Hemoptysis (even if minimal)—requires immediate CT and likely bronchoscopy 1, 7
• Smoking history >45 years with new or changed cough pattern 6
• Constitutional symptoms (fever, night sweats, weight loss) 1
• Prominent dyspnea out of proportion to examination findings 6
• Hoarseness suggesting recurrent laryngeal nerve involvement 6

Critical Pitfalls to Avoid

• Don't assume radiographic findings are the cause of cough—in elderly patients, chronic changes may be incidental and unrelated to current symptoms 2
• Don't order CT prematurely—studies show 82-93% of chronic cough cases are diagnosed and successfully treated using standardized clinical protocols without advanced imaging 6
• Don't treat only one condition—chronic cough is multifactorial in many patients, requiring simultaneous treatment of UACS, asthma, and GERD to achieve resolution 1
• Don't dismiss these findings entirely—while often benign, they may represent early manifestations of bronchiectasis or interstitial lung disease requiring specific therapy 2
• Don't delay evaluation beyond 8 weeks—if empiric treatment fails after adequate trials (typically 4-8 weeks total), proceed to HRCT to evaluate for bronchiectasis, interstitial lung disease, or occult malignancy 1, 6

Malignancy Considerations

While the prevalence of malignancy in chronic cough populations is low (1-2%), vigilance is required: 1, 2

• Both patients with malignancy in one retrospective series had normal chest radiographs but suspicious clinical findings 1
• In smokers with persistent cough, bronchoscopy may be indicated even with normal radiographs, as 16% of central airway tumors are radiographically occult 1, 7