Is chronic cough a symptom of Eosinophilic Esophagitis (EE)?

Chronic Cough is Not a Common Symptom of Eosinophilic Esophagitis

Chronic cough is not a typical symptom of Eosinophilic Esophagitis (EoE) and should prompt investigation for other more common causes of chronic cough. While EoE is characterized by eosinophilic inflammation of the esophagus, its primary symptoms relate to esophageal dysfunction rather than respiratory manifestations.

Clinical Presentation of Eosinophilic Esophagitis

EoE is defined as a chronic, immune/antigen-mediated disease characterized by:

• Primary symptoms: Dysphagia, food impaction, feeding difficulties, heartburn, regurgitation, vomiting, chest pain, odynophagia, abdominal pain, and malnutrition 1
• Diagnostic criteria: Symptoms of esophageal dysfunction plus histologic evidence of eosinophil-predominant inflammation (>15 eosinophils per high-power field) 1
• Demographics: Most common in adult White men with high concurrence of atopic conditions 2

Common Causes of Chronic Cough

When evaluating chronic cough, the following conditions should be prioritized:

1. Upper airway cough syndrome (UACS) - formerly known as post-nasal drip syndrome
2. Asthma
3. Gastroesophageal reflux disease (GERD)
4. Non-asthmatic eosinophilic bronchitis (NAEB)

These four conditions account for 92-100% of chronic cough cases in non-smoking patients not taking ACE inhibitors and with normal chest radiographs 1.

Relationship Between EoE and Respiratory Symptoms

While some research suggests potential extraesophageal manifestations of EoE, the evidence for chronic cough as a direct symptom of EoE is limited:

• Some case reports mention chronic cough in EoE patients, but this is likely due to comorbid conditions rather than EoE itself 3
• EoE patients often have other atopic conditions like asthma, allergic rhinitis, and eczema that can independently cause cough 2, 4
• When respiratory symptoms occur in EoE patients, they typically include hoarseness, recurrent croup, and subglottic stenosis rather than chronic cough 4

Diagnostic Approach for Chronic Cough

When evaluating chronic cough, consider:

1. Rule out common causes first:

   • UACS (post-nasal drip syndrome)
   • Asthma (including cough-variant asthma)
   • GERD
   • Non-asthmatic eosinophilic bronchitis 1

2. Specific testing:

   • Sputum eosinophil count (>3% indicates eosinophilic airway inflammation) 1, 5
   • Methacholine challenge test for bronchial hyperresponsiveness 5
   • 24-hour pH monitoring for GERD 1

3. Consider EoE only when:

   • Patient has primary esophageal symptoms (dysphagia, food impaction)
   • Other causes of chronic cough have been ruled out
   • Patient has other atopic conditions or risk factors for EoE

Clinical Pearls and Pitfalls

• Key distinction: Eosinophilic bronchitis affects the airways and causes cough, while eosinophilic esophagitis affects the esophagus and causes dysphagia/food impaction 1
• Potential confusion: Both GERD and EoE can cause esophageal symptoms, but GERD is a much more common cause of chronic cough than EoE 1
• Diagnostic pitfall: Treating with PPIs empirically before proper evaluation may mask EoE diagnosis 3
• Treatment implications: Chronic cough requires targeted therapy for its specific cause (inhaled corticosteroids for eosinophilic bronchitis, PPIs for GERD, etc.) 5

In summary, while EoE patients may experience cough due to comorbid conditions, chronic cough is not considered a primary or typical symptom of eosinophilic esophagitis. Patients with chronic cough should be evaluated for the more common causes before attributing the symptom to EoE.