Differential Diagnosis: Distinguishing UACS from Asthma and GERD

Chronic cough has a short differential, but the three most common causes—upper airway cough syndrome, asthma, and gastroesophageal reflux disease (GERD)—can overlap in presentation. A patient with persistent cough could have any one of these conditions, or sometimes more than one simultaneously.

So how do you tease them apart during your initial evaluation? The answer lies in associated symptoms, past medical history, and recognizing the characteristic patterns that distinguish each condition, according to Vukiet Tran, MD, an emergency, family medicine, and long-term care physician.

Patient Care® spoke with Vukiet Tran, MD, an emergency, family medicine, and long-term care physician, during the 2025 FMX conference in Anaheim. In this segment, Dr Tran provides a practical framework for differentiating UACS from asthma and GERD, helping clinicians avoid the common pitfall of treating the wrong condition while the real culprit goes unaddressed.

In this segment, Dr Tran covers:

• How asthma history and objective testing guide diagnosis
• The role of wheezing in distinguishing asthma from UACS
• GI symptoms that point toward reflux as the primary cause
• Why proper diagnosis matters before starting empiric treatment

The following transcript has been lightly edited for flow and style.

Patient Care: How can clinicians differentiate UACS from other common causes of chronic cough, such as asthma or GERD, during an initial evaluation?

Tran: Let’s take asthma first. Patients with asthma typically have a history of it and may already use inhalers. Their diagnosis should be confirmed with pulmonary function or methacholine testing. In asthma, the cough is often accompanied by wheezing—something we don’t see with upper airway cough syndrome.

In contrast, GERD-related coughs are usually associated with gastrointestinal symptoms such as throat pain, heartburn, bad breath, chest or abdominal pain, and sometimes nausea or vomiting. Some patients may have reflux laryngitis, where acid irritation causes a cough, but again, those symptoms tend to come with other GI signs. So if the cough presents alongside those, reflux is more likely.

Dr Tran is the co-founder and president of the Canadian Physicians' Pension Plan, and an assistant professor in the Department of Family and Community Medicine at the University of Toronto.

Series Navigation

• Part 1: Defining Acute, Subacute, and Chronic Cough: A Clinical Framework
• Part 2: Recognizing Upper Airway Cough Syndrome: Key Clinical Clues
• Part 3: Differential Diagnosis: Distinguishing UACS from Asthma and GERD (You are here)
• Part 4: Evidence-Based Treatment of Upper Airway Cough Syndrome (coming soon)