Post-nasal drip

PND may present itself through the constant presence of discomfort in the upper airways. It is classically described as the sensation of a substance "dripping down the throat" and may also present with rhinorrhea, constant throat clearing, and cough, although its symptoms can be very nonspecific. PND is one of the most common etiologies for chronic cough, defined as a cough persisting beyond 8 weeks. Post-nasal drip can be a cause of laryngeal inflammation and hyperresponsiveness, leading to symptoms of vocal cord dysfunction. == Causes ==

There are multiple causes of PND, which can be acute or chronic. GERD Gastroesophageal reflux disease (GERD) is often associated with a high prevalence of upper-respiratory symptoms similar to those of PND, such as coughing, throat clearing, hoarseness and change in voice. Reflux causes throat irritation, leading to a sensation of increased mucus in the throat, which is believed to aggravate and, in some cases, cause post-nasal drip. This persistent irritation can lead to increased mucus production as a result of pro-inflammatory pathways, producing symptoms of PND. == Mechanism ==

The exact mechanism of PND depends on its etiology, but usually involves increased production of mucus from the nasal mucosa. In addition to providing sense of smell, the nasal cavity serves to filter and regulate the temperature and humidity of inspired air. The nasal mucosa can produce secretions, or mucus, that provides lubrication and protection for the nasal cavity. This mucus production is activated by the autonomic nervous system; specifically, cholinergic neuropeptides are responsible for increasing mucus production. In some patients, mucus recirculation between natural and accessory ostia has been described as a mechanism that perpetuates post-nasal drip and chronic rhinosinusitis. ==Diagnosis==

Diagnosis of PND depends on both a detailed history and clinical examination to help determine its etiology. The history may begin with feelings of obstructed nasal breathing or "stuffy nose" with or without nasal discharge. If allergic rhinitis is suspected, a family history of allergic conditions as well as a personal history of other associated conditions such as food allergy, asthma, and atopic dermatitis can be evaluated. In patients with accessory ostium recirculation, a condition often overlooked, careful nasal endoscopy may sometimes reveal a characteristic ring of mucus flow between adjacent openings. recirculates back into the maxillary sinus through an accessory ostium. ==Treatment==

Treatment options depend on the nature of an individual's post-nasal drip and its cause. Antibiotics may be prescribed if the PND is the result of bacterial sinusitis. Decongestants such as pseudoephedrine can tighten blood vessels of the nasal mucosa and result in a decrease in mucus production. One study has found that symptoms of postnasal drainage improved after 8 to 16 weeks of lansoprazole 30 mg taken twice daily regardless of the presence or absence of typical symptoms of GERD. Other methods, such as drinking warm fluids and using saline nasal irrigation, may be useful for managing symptoms of PND but their exact efficacy is unclear in medical literature. Nevertheless, since postnasal drip is frequently associated with chronic rhinitis, the regular application of various saline solutions to the nasal cavity may be beneficial. == Epidemiology ==

Because PND is often characterized as a "symptom" rather than a separate condition, the exact incidence is unknown and varies by its etiology. Chronic rhinitis, which includes allergic and non-allergic rhinitis, can affect 30-40% of the population. Non-allergic rhinitis is more common in females than in males. == References ==