What is Post-Nasal Drip?

Postnasal drip syndrome (PNDS) is the most common but easily overlooked cause of chronic cough. The cough guidelines issued by the American College of Chest Physicians (ACCP) in 1998 clearly state that postnasal drip syndrome (PNDS), cough variant asthma (CVA), and gastroesophageal reflux (GER) are the most common causes of chronic cough. The incidence rate is 85% ~ 98%. The latest "Guidelines for Diagnosis and Treatment of Cough" promulgated in China also pointed out that: postnasal drip syndrome (PNDS) is a common cause of chronic cough. US researchers have found that postnasal drip syndrome (PNDS) accounts for 28% to 57.6% of patients with chronic cough, while European researchers believe that less than a quarter of patients have postnasal drip syndrome (PNDS).

Postnasal drip syndrome

Postnasal drip syndrome (PNDS) refers to the chronic inflammation of the nasal cavity and sinuses. The purulent secretions produced by the inflammation site flow back through the nasal cavity and flow into the nasopharynx, oropharynx, hypopharynx through the nostril. Long-term chronic stimulation of purulent secretions causes secondary inflammation and related symptoms in the above parts, which is often one of the root causes of clinical chronic cough. Common diseases that cause postnasal drip syndrome include chronic rhinitis, chronic sinusitis, and chronic Nasopharyngitis and so on.

Overview of postnasal drip syndrome

PNDS Pathogenesis of Postnasal Drip Syndrome (PNDS)

Postnasal drip syndrome (PNDS) is a syndrome mainly due to cough due to nasal diseases that cause secretions to flow back to the nose and throat, and even back into the glottis or trachea.

At present, most people believe that inflammatory lesions in the nasal cavity and sinuses can stimulate cough receptors distributed in the nose, sinuses, throat, etc., and cause them to have an inflammatory response similar to that of the lower respiratory tract. Can stimulate the sensory nerves of the airway, thereby increasing the sensitivity of the cough reflex. In addition, in the case of postnasal drip syndrome (PNDS), excessive secretions from the nose or sinuses drip back into the throat, causing physical stimulation of the cough and afferent nerves of the throat to trigger cough. Many diseases can cause postnasal drip syndrome (PNDS), such as common cold, allergic rhinitis, non-allergic rhinitis, vasomotor rhinitis, infectious rhinitis, and so on.

PNDS Diagnosis of Postnasal Drip Syndrome (PNDS)

Postnasal drip syndrome (PNDS) is one of the most common causes of chronic cough. Therefore, patients with chronic cough should consider the possibility of retronasal drip syndrome (PNDS). On the other hand, because postnasal drip syndrome (PNDS) involves a variety of underlying diseases, its diagnosis is mainly based on a comprehensive history of medical history, related examinations, and response to specific treatments. Therefore, we should rule out other common causes of chronic cough before confirming the diagnosis of postnasal drip syndrome (PNDS).

The diagnostic criteria for nasal drip syndrome (PNDS) recommended by China's "Guidelines for the Diagnosis and Treatment of Cough" are as follows: (1) paroxysmal or persistent cough, mainly during the day, and less coughing after falling asleep; (2) nose Posterior drip and / or mucus attachment on the posterior pharyngeal wall; (3) History of rhinitis, sinusitis, nasal polyps or chronic pharyngitis; (4) Examination of mucus on the posterior pharyngeal wall, cobblestone-like view; (5) ) Cough relief after targeted treatment.

Different underlying diseases of postnasal drip syndrome (PNDS) can be examined accordingly. It should be noted that the diagnosis of postnasal drip syndrome (PNDS) lacks specificity, and the diagnosis of postnasal drip syndrome (PNDS) cannot be completely ruled out when patients do not meet these diagnostic criteria, as a significant proportion of patients with chronic cough are A "concealed" postnasal drip syndrome (PNDS) can only be diagnosed based on the effects of specific treatments for postnasal drip syndrome (PNDS).

PNDS Treatment of Postnasal Drip Syndrome (PNDS)

Patients suspected of having postnasal drip syndrome (PNDS) should be treated specifically based on their underlying disease. For PNDS caused by common cold, non-allergic rhinitis, vasomotor rhinitis, year-round rhinitis, etc., first-generation antihistamines (such as chlorpheniramine maleate) and decongestants (pseudoephedrine hydrochloride) are preferred. ). Most patients develop efficacy within a few days to two weeks after initial treatment. Postnasal drip syndrome (PNDS) caused by allergic rhinitis is effective with various antihistamines. The second-generation antihistamines without sedation are preferred. The commonly used drugs are loratadine or aspartame. Azole, etc. Nasal inhaled glucocorticoids are the drug of choice for allergic rhinitis. The inhaled dose is usually 50 g / time / nostril or other equivalent inhaled glucocorticoids 1 to 2 times a day. Sodium cromoglycate also has a good preventive effect on allergic rhinitis. The applied dose is 20 mg / time, 3 to 4 times a day. Improving the environment and avoiding allergen stimulation are effective measures to control allergic rhinitis. Allergen immunotherapy may be effective, but the onset time is longer.

The main treatment of acute bacterial rhinosinusitis is the application of antibacterial drugs. When the effect is poor or the secretion is large, nasal inhalation of glucocorticoids and decongestants can be used to reduce inflammation. For the treatment of chronic sinusitis, the guideline recommends the following initial treatment schemes: application of antibacterial drugs effective for Gram-positive bacteria, Gram-negative bacteria and anaerobic bacteria for 3 weeks; oral administration of first-generation antihistamines and decongestants for 3 weeks Nasal decongestant for 1 week; nasal inhaled glucocorticoid for 3 months. When medical treatment is not effective, negative pressure drainage, puncture drainage or surgery can be performed.

It should be noted in the treatment of postnasal drip syndrome (PNDS) that not all antihistamines have the same effect. Current research suggests that first-generation antihistamines and decongestants are the most effective treatment for most patients with postnasal drip syndrome (PNDS), and postnasal drip syndrome (PNDS) caused by non-allergic causes ) Is not mediated by histamine, and treatment with second-generation antihistamines is likely to be ineffective.

Conclusions of postnasal drip syndrome

Postnasal drip syndrome (PNDS) is easily missed and misdiagnosed clinically. The main reason is that the physician lacks knowledge of postnasal drip syndrome (PNDS). He only pays attention to the performance of the tonsils, pharynx and lungs, and sees the texture of the chest radiograph Thickness is the diagnosis of interstitial pneumonia, and the patient's medical history and other signs are ignored. In fact, postnasal drip syndrome (PNDS) is the most common cause of chronic cough. Patients with chronic cough who have not been able to determine the cause can be given specific empirical treatment for postnasal drip syndrome (PNDS) and diagnosed based on the efficacy disease.