Overview

Laryngopharyngeal reflux is a condition characterised by the backwards flow of gastric contents into the larynx and pharynx.

GERD presents itself with heartburn, but no such symptom is present with LPR; hence, it often goes undiagnosed. Since it can affect the delicate tissues of the upper airway directly, its detailed study and awareness are important for maintaining respiratory health.

What is laryngopharyngeal reflux?

In healthy individuals, the contents from the stomach are prevented from coming up to the upper respiratory tract by 4 barriers:¹

• The lower esophageal sphincter
• The upper esophageal sphincter
• Esophageal peristalsis 
• Epithelial resistance factors.

LPR occurs due to dysfunction in any of the four barriers. The upper sphincter acts as a critical barrier protecting the larynx and pharynx from gastric reflux. The cricopharyngeus, the thyropharyngeus, and the proximal esophageal musculature form the complex of the upper esophageal sphincter. The sphincters remain closed except for swallowing. The tone of these muscles is reduced during sleep, general anaesthesia, and smoking. 

When this barrier fails, acidic and enzymatic contents, particularly pepsin, can reach the laryngopharynx, resulting in mucosal injury. The epithelium also has a layer of mucus, which prevents pepsin from attacking the submucosal layers, but cannot resist the acid for very long.

In addition to the mucus layer, there is also an aqueous layer, which forms an alkaline buffer for the acid.

Pepsin remains active in an acidic environment but can be reactivated at low pH after being deposited in the upper airway tissues, leading to chronic inflammation even when the reflux episodes are infrequent or non-acidic.

Epidemiology

LPR affects children and adults. A study in Shanghai Children’s Hospital, China, revealed that in children suffering from chronic cough, 36% were suffering from LPR. This warrants more attention now than ever.

Etiology

GERD and LPR have similar symptoms, and their etiology is also very similar. It is caused due to:

• Obesity
• Having a diet high in fats 
• Sleeping immediately after a heavy meal
• Smoking
• Alcohol
• Caffeine 
• Stress, anxiety, and other neurological issues

Impact on breathing and airway health:

Laryngeal and upper airway inflammation:

Laryngeal and pharyngeal mucosal inflammation is the first consequence of LPR. Laryngoscopy in LPR patients would reveal: 

• Posterior laryngeal erythema(redness)
• Edema (swelling)
• Vocal fold granulation
• Interarytenoid hypertrophy

Clinically:

• Hoarseness and a lump in the throat feeling
• Dysphagia
• Coughing while lying down after a meal
• Difficulty in breathing or a feeling of choking
• Heartburn

Reflux and direct airway effects

LPR acts directly and reflexively on the respiratory system. Asthma-like symptoms of bronchospasm, chronic cough, and wheezing can occur due to microaspiration of the gastric contents into the lower airways. This can aggravate existing asthma too.

Also, activation of the vagal afferents in the laryngopharynx can lead to reflex bronchoconstriction and increased cough reflex sensitivity. This explains the chronic dry non non-productive cough.

Airway obstruction and respiratory complications

Chronic upper respiratory inflammation can lead to laryngospasm, paradoxical vocal fold motion, and sometimes subglottic stenosis.

LPR can contribute to chronic rhinosinusitis and poorly controlled asthma.

Diagnosis

The diagnosis of LPR can be accomplished through tools that include:

• Reflux symptom index

It is a self-assessment questionnaire, developed by Dr. Jamie Koufman, that helps both patients and doctors evaluate the symptoms of LPR.

It consists of 9 questions, each rated on a scale from 0-5, where 0=no problem, 5=severe problem.

• Reflux finding score

Dr. Jamie Koufman also developed this to assess the visible signs of reflux-related damage in the throat and the larynx. It helps diagnose and track the response to treatment of LPR. It also helps differentiate LPR from other types of throat conditions.

• Flexible laryngoscopy

Flexible laryngoscopy is a diagnostic procedure where a thin, flexible tube with a light and camera (called a laryngoscope) is gently inserted through the nose to visualise the nasal passages, throat, and larynx. It helps view real-time images of the anatomic structures during speech, breathing, and swallowing.

• Dual probe 24-hour pH monitoring

It is the gold standard for diagnosing LPR. It consists of two tiny sensors placed on a thin catheter: one at the lower esophagus and the other at the upper esophagus. It connects to a small portable recorder that the individual wears to track reflux events.

It helps measure:

• Acid exposure time
• Number and duration of reflux episodes
• Whether reflux reaches the upper airway
• Correlation between symptoms and reflux events

• Biomarkers  
  • Pepsin:
    • Pepsin is a digestive enzyme produced in the stomach. Pepsin detection in the oral cavity or the pharynx at different times of the day, post-meals, or after an episode is the new non-invasive technique for diagnosing LPR³
  • Bile acids:
    • It is the digestive fluid secreted by the liver. Its presence in the esophagus can indicate duodeno-esophageal reflux
  • Inflammatory markers: 
    • Presence of inflammatory markers like IL-6, IL-8, in the pharynx indicates chronic irritation to the tissues caused by reflux

Management

Lifestyle modifications

Weight loss¹

• Decrease in meal size
• The meal should be high in fibre and lean protein
• Avoid sleeping for 3 hours after a meal
• Avoid saturated fats
• Avoid smoking
• Avoid caffeine and alcohol
• Avoid aerated beverages

Stress reduction

Studies show that individuals with stress and anxiety are more prone to LPR. The gastric secretions are controlled by the brain (autonomic nervous system), and mental issues change the response of the brain, which in turn affects the physiology of the body. The mind-body connection cannot be denied.

Various methods of stress reduction, through medication or meditation, should be sought to lessen the extent of severity of LPR. Yoga, Pilates, Zumba, and any form of physical exercise will help reduce stress and increase levels of the happiness hormone.

Sleep

Sound sleep provides the much-needed rest and repair for the body. Additionally, each hour that we are awake beyond 10 pm increases acid production, hunger pangs, nocturnal eating, and poor digestion. 

The circadian rhythm should be regularised so that the body works according to the biological clock. Set times for waking and sleeping should be practised to regulate acid production.

Some of the other precautions that can be taken around bedtime to reduce LPR include:

• Keeping the head elevated 6-8 inches will prevent the acid from entering the throat
• Avoid eating anything at least 3 hours before bed. Avoiding fatty and spicy meals, alcohol, and caffeine for dinner will be an added advantage
• Sleeping on the left side will help reduce the reflux
• Having a good sleep environment is equally important for reducing stress and for a good night’s sleep. Keeping the room cool and dark, with some aromatic oils that help induce deep sleep, reduces reflux by improving sleep quality

Proton pump inhibitors

Proton pump inhibitors reduce stomach acid production by blocking acid-producing enzymes in the stomach lining. The examples of PPIs are omeprazole, pantoprazole, etc.

Proton pump inhibitors are cost-effective and useful in the long-term management of LPR. The full dose of PPIs is continued for 2-3 months. They are 82-94% effective in completely curing LPR symptoms.¹⁴

Though PPIs give a lot of symptomatic relief, there is always a chance of LPR starting again due to stress and lifestyle issues. Lifestyle changes will ensure that LPR does not occur again.

Alginates

Alginates are natural compounds from brown algae. When combined with saliva or stomach acid, they form a gel that floats on top of the stomach contents, preventing reflux of acid into the esophagus.

Magnesium alginate suspension, along with simethicone, is as effective as proton pump inhibitors for managing LPR.

They can be taken alone in milder cases or with PPIs for better results. It takes 3-4 weeks for the full effect. The main advantage of alginates is that they are drug-free and can be used by pregnant women safely.

Again, relying solely upon alginates without addressing the stress and lifestyle issues will give only temporary relief from LPR.

H2 receptor antagonists

H2 receptor antagonists work by blocking histamine 2 receptors in the stomach lining, which reduces acid production. They act faster than PPIs but are less effective. E.g.. Ranitidine, Famotidine.

One disadvantage is that long-term use of these can cause tolerance, apart from headache, dizziness, and constipation, which are the other side effects of H2 receptor antagonists. 

Nissen fundoplication

This surgery is indicated only when the LPR is drug and diet-resistant.³

This surgery involves wrapping the upper stomach(fundus) around the lower end of the esophagus. This strengthens the lower esophageal sphincter and prevents the reflux of acid from the stomach to the esophagus.

Conclusion

Undiagnosed and untreated laryngopharyngeal reflux can lead to chronic vocal cord damage and can cause laryngeal carcinoma and adenocarcinoma.¹ 

It is also known as the “silent” reflux, as it does not have the heartburn associated with GERD and often goes undiagnosed. So if you suffer from any chronic cough or voice changes, please get yourself checked, the earlier the better.