From the Guidelines
Upper airway cough syndrome (UACS), formerly known as postnasal drip syndrome, is a common cause of chronic cough that should be treated with first-generation antihistamines combined with decongestants, such as chlorpheniramine 4mg or diphenhydramine 25mg every 6-8 hours, plus pseudoephedrine 60mg every 6-8 hours for 2-3 weeks, as this approach has been shown to be effective in reducing symptoms and improving quality of life 1.
Diagnosis of UACS
The diagnosis of UACS-induced cough should be determined by considering a combination of criteria, including symptoms, physical examination findings, radiographic findings, and, ultimately, the response to specific therapy 1.
- Symptoms such as chronic cough, nasal congestion, and postnasal drip are common presentations of UACS.
- Physical examination findings, such as nasal mucosal thickening and purulent discharge, can support the diagnosis.
- Radiographic findings, such as sinusitis or nasal polyps, can also be present in some cases.
Treatment of UACS
Treatment of UACS typically begins with first-generation antihistamines combined with decongestants, such as chlorpheniramine 4mg or diphenhydramine 25mg every 6-8 hours, plus pseudoephedrine 60mg every 6-8 hours for 2-3 weeks 1.
- For patients with allergic rhinitis causing UACS, intranasal corticosteroids like fluticasone propionate (1-2 sprays per nostril daily) or mometasone furoate are effective 1.
- Nasal saline irrigation using a neti pot or saline spray several times daily can help clear mucus and reduce symptoms.
- For cases related to sinusitis, antibiotics may be necessary, typically amoxicillin-clavulanate 875/125mg twice daily for 5-7 days 1.
Management of UACS
Patients with UACS should also avoid irritants like cigarette smoke, maintain adequate hydration, and elevate the head of the bed to reduce nighttime symptoms 1.
- If symptoms persist beyond 4 weeks despite appropriate treatment, further evaluation for other causes of chronic cough is warranted 1.
- An empiric trial of therapy for UACS should be administered because the improvement or resolution of cough in response to specific treatment is the pivotal factor in confirming the diagnosis of UACS as a cause of cough 1.
From the FDA Drug Label
Temporarily relieves these symptoms due to hay fever or other upper respiratory allergies: • runny nose • itchy, watery eyes • sneezing • itching of the nose or throat
The diagnosis of Upper Airway Cough Syndrome (UACS), also known as Postnasal Drip Syndrome, is not directly addressed in the provided drug label. For treatment, loratadine (PO) may be used to relieve symptoms of upper respiratory allergies, which can be a cause of UACS. Key symptoms that may be relieved by loratadine include:
- runny nose
- itchy, watery eyes
- sneezing
- itching of the nose or throat 2
From the Research
Diagnosis of Upper Airway Cough Syndrome (UACS)
- UACS is a clinical diagnosis of exclusion with no diagnostic testing or objective findings 3
- It can be present with or without associated rhinitis and chronic rhinosinusitis 3
- Diagnosis is confirmed when therapeutic intervention results in symptom resolution 3
Treatment of Upper Airway Cough Syndrome (UACS)
- Treatment includes dual therapy with H1 receptor antihistamines and decongestants 3
- Older-generation H1 antihistamines are recommended in empiric protocols for the treatment of cough due to UACS 4
- Newer-generation H1 antihistamines are not useful in the treatment of cough due to UACS 4
- Antihistamine-decongestant combinations may be effective in reducing cough symptoms 5, 6
- There is no good evidence for or against the effectiveness of OTC medicines in acute cough, including those used to treat UACS 5
Mechanism of Action
- The mechanism of action of older-generation H1 antihistamines in UACS is not fully understood, but may involve anticholinergic activity or actions on histamine H1 and/or nonhistaminergic receptors in the central nervous system 4
- The effects of older H1 antihistamines may also be molecule specific, rather than attributable to the entire class of compounds 4