Ep 177 – Postnasal drip

Postnasal drip is a condition where excess mucus from the nose and sinuses accumulates and flows down the back of the throat. This can lead to symptoms such as throat clearing, coughing, a scratchy or sore throat, hoarseness and bad breath. Common causes include allergies, colds, sinus infections, weather changes, acid reflux and irritants such as smoke. Treatment typically involves managing the underlying cause through medications such as antihistamines, decongestants and nasal sprays, as well as maintaining proper hydration. If symptoms persist for more than 10 days or are accompanied by fever or discoloured mucus, medical evaluation is recommended to rule out infections or other issues. In this episode, Dr Roger Henderson provides an overview of these areas to help us easily diagnose this common problem in our surgeries.

Key take-home points

• Postnasal drip (PND) is a descriptive term referring to the sensation of mucus accumulation in the throat or dripping from the posterior nasal cavity into the pharynx.
• PND is not a diagnosis in itself, but a symptom that results from various conditions that affect mucus production or clearance.
• A structured approach to evaluating the patient with PND is critical for effective treatment and symptom resolution.
• The nasal epithelium plays an essential role in respiratory defence mechanisms through the continuous production of mucus, typically 1–2 litres a day.
• Inflammation, infection, anatomical obstruction or altered mucus viscosity can all lead to the accumulation of mucus, and it is this that patients then perceive as PND.
• Allergic rhinitis remains one of the most common causes of PND and is a very common problem, affecting over 20% of the UK population.
• Non-allergic rhinitis encompasses a group of disorders which are not mediated by immunoglobulin E. These include vasomotor rhinitis, hormonal rhinitis, drug-induced rhinitis and idiopathic forms. All these conditions can lead to increased nasal secretions and impaired clearance.
• Both acute and chronic sinusitis are important considerations in any patient presenting with persistent PND.
• Gastroesophageal reflux disease and its variant, laryngopharyngeal reflux, are increasingly becoming recognised as important contributors to PND.
• Nasal polyps, septal deviations, enlarged adenoids and obstructive lesions can all lead to impaired sinus drainage and chronic mucus accumulation.
• The diagnosis of PND is primarily a clinical one, supported by a detailed history and physical examination.
• Key questions to ask include the timing, duration and character of mucus, the presence of associated symptoms (such as sneezing, nasal congestion, facial pain and cough), whether there are any environmental triggers, medication use and sleep positioning.
• The management of PND is relatively straightforward as it depends entirely on addressing the underlying cause.
• Where aetiology is unclear – or symptoms persist despite initial management – then referral is warranted, where evaluation may include allergy testing, laryngoscopy and imaging studies.

Key references

1. Orlandi RR, et al. Int Forum Allergy Rhinol. 2021;11(3):213-739. doi: 10.1002/alr.22741.
2. Smallwood D, et al. J Allergy Clin Immunol Pract. 2024;12(6):1472-1478. doi: 10.1016/j.jaip.2024.04.030.
3. Yu JL, Becker SS. Curr Opin Otolaryngol Head Neck Surg. 2016;24(1):15-19. doi: 10.1097/MOO.0000000000000226.
4. Ryan MW. Med Clin North Am. 2010;94(5):913-21. doi: 10.1016/j.mcna.2010.05.009.
5. Pratter MR, et al. Chest. 2006;129(1 Suppl):63S-71S. doi: 10.1378/chest.129.1_suppl.63S.