Overview

In 2002, the American Academy of Otolaryngology-Head and Neck Surgery introduced the concept of Laryngopharyngeal reflux disorder (LPRD). Many researchers believe that LPRD is a form of extraesophageal symptoms (symptoms occurring beyond the oesophagus) of GERD. But, otolaryngologists regard LPRD as a distinct clinical entity. Recent studies indicate LPRD is closely associated with sinusitis, otitis media, asthma, and laryngeal cancer. Although LPRD has gradually developed in recent years, its prevalence has become more evident in this decade.¹ Following some American studies, LPR symptoms would concern 4% to 10% of outpatients visiting Otolaryngology- Head and Neck Surgery departments, and up to 50% of patients visit voice centres.²

What is laryngopharyngeal reflux(LPRD)?

Laryngopharyngeal reflux disorder (LPRD), also known as “silent reflux” or “airway reflux,” is an inflammatory disorder affecting the tissues of the upper aerodigestive tract. It results from both the direct and indirect effects of reflux of contents from the stomach and duodenum, causing structural changes and inflammation, particularly in the vocal cords.^2,3

How is the voice box or vocal cords affected by LPRD?

Reflux of gastric and duodenal contents (refluxate) is a major cause of laryngeal pathology. Laryngeal pathology results from small amounts of refluxate (stomach acid flowing backwards or regurgitated into the food pipe), typically occurring while sitting upright during the daytime, causing damage to laryngeal tissues and producing localised symptoms.³

There are 4 barriers protecting the upper aerodigestive tract from reflux injury: the lower oesophageal sphincter (LES), oesophageal motor function with acid clearance, oesophageal mucosal tissue resistance, and the upper oesophageal sphincter (UES). The area behind the voice box that normally functions to clear mucus from the tracheobronchial tree is altered when these barriers fail, causing stagnation of mucus. The subsequent accumulation of mucus produces postnasal drip (extra mucus dripping down the back of the throat) and provokes throat clearing. Irritation by refluxate can directly cause coughing and choking (laryngospasm) that inflames vocal cords, leading to vocal fold oedema, contact ulcers, and granulomas that cause other LPR-associated symptoms. ⁴

Breaching your LES

The LES serves as the primary defence against acid reflux from the stomach and duodenum. Frequent and significant acid reflux can lead to GERD symptoms. However, small amounts of acid may occasionally enter your oesophagus without causing any noticeable symptoms. Your oesophagus has many layers of protection against acid reflux, hence it cannot be harmed so easily. But your throat lacks the same protection. ⁵

Oesophageal motor function disruption with delay in acid clearance

Acid in the oesophagus gets cleared by a two-step process. Initially, the maximum amount of liquid in the oesophagus is cleared quickly by gravity or by the oesophageal muscle movements (peristalsis). But removal of the liquid differs from clearance of the acid. After the liquid is removed, the small amount of leftover acid (about 1 mL) is gradually neutralised by swallowed saliva, which brings the acid level (pH) back to normal.

Many studies suggest that about half of patients with reflux disease have markedly longer acid clearance times. ⁶

Disruption in oesophageal mucosal tissue resistance

The mucosa of the inner portion of the oesophagus gets damaged, and the composition of oesophageal microbiota (commensal bacteria) gets altered when exposed to mixed (acid and bile) reflux. The most severe damage happens when stomach acid and bile combine at very low pH levels (between 1 and 3). This significantly raises the risk of developing conditions such as Barrett’s oesophagus, cellular abnormalities (dysplasia), and even oesophageal cancer. Research indicates that the combination of hydrochloric acid, pepsin, and bile acids causes the most damage to the oesophageal lining.⁷

Breaching your UES(upper esophageal sphincter) ⁵

When stomach acid rises into your oesophagus, the upper oesophageal sphincter (UES) acts as a barrier to protect your throat. Even a small amount of acid reflux in the oesophagus can easily irritate the delicate tissues of your throat. Unlike the oesophagus, the throat lacks a protective lining and efficient mechanisms to clear out the reflux, causing the acid to linger there for a longer time.

Symptoms of LPR

With LPR, the vocal cords become inflamed and damaged. 

Symptoms are as follows:^{5 6}

• Waking up in the middle of the night from a sound sleep, coughing (or even grasping for air like a fish out of water, i.e. laryngospasm
• Morning hoarseness
• Chronic intermittent hoarseness
• Increased phlegm or mucus in the throat
• A sensation of a lump in the throat is always present except at the time when you are eating
• Excessive throat clearing
• A chronic cough for more than two months, even if your lungs do not have any pathology
• Difficult swallowing
• Sore or burning throat
• Sour or bitter taste in the mouth

These symptoms worsen in the morning and after eating food (especially spicy food). 

Treatment

LPR can usually be treated without the need for medication, as it may only be caused by a small amount of acid. Therefore, it is better managed by lifestyle modifications such as eating healthily, avoiding triggers such as spicy foods or eating and then immediately lying down, smoking cessation, and reducing alcohol intake. However, a healthcare professional may prescribe medications such as PPIs (e.g., omeprazole, lansoprazole), H2 blockers (e.g., cimetidine), and alginates (e.g., in Gaviscon), which aid the process of neutralising the acid, reducing its production, and protecting against irritation. Prokinetic agents (such as azithromycin) can also be prescribed in cases where the patient is unresponsive to PPI treatment.⁷

Summary

Patients with LPRD who suffer from severe symptoms may experience greater physical and mental strain, along with low quality of life and emotional well-being.¹ LPRD condition is difficult to diagnose and treat, with no gold standard for its diagnosis or treatment, which hampers the healthcare system. In addition, the exact mechanism of disease pathology is unknown and likely due to a combination of factors, which further complicates the picture.²  Treatment mainly consists of lifestyle modifications, but medications such as PPIs, H2 blockers, alginates, and prokinetic agents can also be prescribed to neutralise the acid and prevent irritation.

FAQs

How is LPR different from GERD?

GERD, known as chronic acid reflux, happens when stomach acid often glides back into the foodpipe(oesophagus), travelling from below the throat towards the stomach. It occurs because the lower oesophageal sphincter (LES) is unable to restrict the acid flow into the oesophagus. But when acid rises even further into the throat, crossing the upper oesophageal sphincter (UES), it leads to LPRD. Some people experience both GERD and LPR, while others have symptoms only related to LPR.⁵ Unlike GERD, laryngopharyngeal reflux often doesn’t cause common symptoms like heartburn or regurgitation.³

How is a case of LRPD treated?⁴

Treatment methods include 

• Patient education and behavioural change: weight loss, smoking cessation, alcohol avoidance, dietary changes
• Medical management: drugs like PPIs, H2 receptor antagonists, prokinetic agents, and alginates
• Surgery (only when the oesophageal sphincter muscles are affected, like a hiatal hernia)

What is the prognosis of LPR post its treatment and management?⁵

An accurate diagnosis and figuring out the contributing factors can aid in a brief and effective treatment process. Hence, long-term prescribed medications or other interventions become ineffective for many people. Proper lifestyle modifications and taking care of your throat and voice while it heals are essential.