What is Upper Airway cough syndrome?

From the Guidelines

Upper Airway Cough Syndrome (UACS) is a common cause of chronic cough characterized by mucus dripping down the back of the throat from the nose or sinuses, triggering the cough reflex. This condition typically results from conditions like allergic rhinitis, sinusitis, or vasomotor rhinitis. The diagnosis of UACS is based on a combination of criteria, including symptoms, physical examination findings, radiographic findings, and response to specific therapy 1.

Key Characteristics of UACS

• Mucus dripping down the back of the throat from the nose or sinuses
• Triggering the cough reflex
• Conditions like allergic rhinitis, sinusitis, or vasomotor rhinitis are common causes
• Symptoms may include a sensation of something draining into the throat, a need to clear the throat, a tickle in the throat, nasal congestion, or a nasal discharge 1

Treatment Options

• First-generation antihistamines with decongestants, such as brompheniramine plus pseudoephedrine or chlorpheniramine plus pseudoephedrine
• Intranasal corticosteroids like fluticasone (2 sprays per nostril daily) or mometasone for allergic causes
• Nasal saline irrigation to clear mucus and irritants
• Antibiotics such as amoxicillin-clavulanate (875/125 mg twice daily for 5-7 days) if sinusitis is present
• Avoiding triggers like smoke, strong odors, and allergens when possible 1

Diagnosis

UACS is diagnosed clinically based on symptoms and examination findings such as cobblestoning of the posterior pharynx or visible postnasal drainage, though these signs aren't always present even when the condition exists 1.

Important Considerations

• The absence of any of the usual clinical findings does not rule out a response to treatment that is usually effective for UACS cough
• A careful medical history including the character and timing of cough and the complications associated with cough is of little diagnostic value in UACS 1

From the Research

Definition of Upper Airway Cough Syndrome

• Upper airway cough syndrome (UACS), formerly known as postnasal drip syndrome, is one of the most common causes of chronic cough 2, 3.
• UACS is a clinical diagnosis of exclusion with no diagnostic testing or objective findings 2.
• It can be present with or without associated rhinitis and chronic rhinosinusitis 2.

Causes and Pathogenesis

• The pathogenesis of UACS remains unclear, and different definitions and treatments are used by physicians worldwide 3.
• Proposed pathogeneses of UACS include the early postnasal drip theory, subsequent chronic airway inflammation theory, and a recent sensory neural hypersensitivity theory 3.
• Some researchers suggest that UACS is a clinical phenotype of cough hypersensitivity syndrome 3.

Diagnosis and Treatment

• Diagnosis is confirmed when therapeutic intervention results in symptom resolution 2.
• Treatment includes dual therapy with H1 receptor antihistamines and decongestants 2.
• Nasal corticosteroids may be an effective treatment for UACS 4.
• Diagnosis can be aided by selecting appropriate interview and examination items, such as awareness of mucus accumulating in the back of the throat and presence of abnormal echography findings 4.

Clinical Characteristics

• UACS is one of the major causes of chronic cough, often associated with allergic or non-allergic rhinitis, or chronic rhinosinusitis 5.
• Clinical characteristics of UACS patients with allergic and non-allergic rhinitis are similar, with only minor differences between these groups 5.
• UACS may be the most common cause of chronic cough in certain populations, such as in Japan 4.