What causes lpr cough

Overview

Laryngopharyngeal reflux (LPR), often referred to as "silent reflux" because it typically lacks the classic heartburn associated with gastroesophageal reflux disease (GERD), is a condition where stomach acid flows backward into the esophagus and can reach the throat and voice box (larynx). This backward flow of acid irritates the delicate tissues of the larynx and pharynx, leading to a variety of symptoms, one of the most common and persistent being a chronic cough. The cough associated with LPR is often described as a "throat-clearing" cough or a dry, hacking cough that can be particularly bothersome, especially when lying down or after meals.

What is Laryngopharyngeal Reflux (LPR)?

Unlike GERD, where stomach acid primarily affects the lower esophagus and causes heartburn and regurgitation, LPR involves acid reaching higher up into the pharynx (throat) and larynx (voice box). The upper esophageal sphincter, which normally prevents reflux from entering the throat, may be less effective in LPR patients. This allows stomach contents, including acid and digestive enzymes like pepsin, to come into contact with the laryngeal structures. These tissues are much more sensitive to acid than the esophageal lining, leading to inflammation, irritation, and the subsequent cough reflex.

How Does LPR Cause a Cough?

The chronic cough in LPR is a protective reflex. When stomach acid irritates the lining of the pharynx and larynx, nerve endings are stimulated. This stimulation sends signals to the brain, which then triggers the cough reflex as a mechanism to try and expel the irritant and protect the airway from further exposure. Because the exposure to acid can be intermittent and often occurs during sleep or after meals, the cough can be persistent and difficult to pinpoint to a specific cause. It's often a dry cough, but some individuals may experience a sensation of mucus in their throat, leading to frequent throat clearing.

Symptoms of LPR

While a chronic cough is a hallmark symptom, LPR can present with a range of other issues affecting the throat and voice. These may include:

• Hoarseness or a raspy voice, especially in the morning.
• A feeling of a lump in the throat (globus sensation).
• Frequent throat clearing.
• Sore throat or burning sensation in the throat.
• Difficulty swallowing (dysphagia) or a sensation of food getting stuck.
• Postnasal drip sensation.
• Excessive mucus in the throat.
• In severe cases, breathing difficulties or vocal cord irritation.

It's important to note that many people with LPR do not experience heartburn, which is why it's termed "silent reflux." The absence of heartburn does not rule out LPR as a cause of chronic cough.

Causes and Risk Factors for LPR

The exact cause of LPR is not fully understood, but it is believed to involve a combination of factors that compromise the function of the upper esophageal sphincter and increase the exposure of the pharynx and larynx to stomach acid. Common contributing factors and risk factors include:

• Dietary Habits: Consumption of trigger foods and beverages such as spicy foods, fatty foods, chocolate, caffeine (coffee, tea, soda), alcohol, mint, and acidic foods (tomatoes, citrus fruits).
• Lifestyle Factors: Eating large meals close to bedtime, obesity, smoking, and wearing tight clothing around the abdomen can increase intra-abdominal pressure, pushing stomach contents upward.
• Anatomical Factors: Certain anatomical variations or conditions affecting the esophagus or stomach.
• Medications: Some medications can relax the lower esophageal sphincter, potentially contributing to reflux.
• Delayed Stomach Emptying: Conditions that slow the rate at which the stomach empties its contents.

Diagnosis of LPR

Diagnosing LPR can be challenging due to its non-specific symptoms and the absence of typical GERD symptoms. A diagnosis often involves a combination of:

• Medical History and Physical Examination: A doctor will ask about your symptoms, diet, lifestyle, and conduct a physical exam, which may include looking at your throat and vocal cords.
• Trial of Acid-Suppressive Medication: Often, a doctor will prescribe a course of proton pump inhibitors (PPIs) or H2 blockers to see if symptoms improve. A positive response to medication can be indicative of LPR.
• Laryngoscopy: A specialist (like an otolaryngologist or ENT doctor) may perform a laryngoscopy, using a small camera to examine the larynx and pharynx for signs of irritation, inflammation, or swelling consistent with LPR.
• 24-hour pH Monitoring: This test measures the acidity in the esophagus and sometimes the pharynx over a 24-hour period to detect reflux events.
• Esophageal Manometry: This test measures the pressure and muscle activity of the esophagus.

Treatment and Management of LPR Cough

The goal of LPR treatment is to reduce the frequency and severity of reflux episodes and to promote healing of the irritated laryngeal tissues. Treatment typically involves a multi-faceted approach:

• Lifestyle Modifications: These are crucial for managing LPR and include:
  • Elevating the head of your bed by 6-8 inches (using blocks or a wedge pillow).
  • Avoiding lying down for 2-3 hours after meals.
  • Eating smaller, more frequent meals.
  • Avoiding trigger foods and beverages (as listed above).
  • Losing weight if overweight or obese.
  • Quitting smoking.
  • Avoiding tight clothing.
• Dietary Changes: Identifying and eliminating personal trigger foods is essential. A diet rich in alkaline foods and low in acidic, fatty, and spicy components is often recommended.
• Medications:
  • Proton Pump Inhibitors (PPIs): These are the most common medications prescribed to reduce stomach acid production. Higher doses and longer treatment durations than those typically used for GERD may be necessary for LPR.
  • H2 Blockers: These also reduce stomach acid but are generally less potent than PPIs.
  • Prokinetics: Medications that help speed up stomach emptying.
  • Antacids: May provide temporary relief but are not a long-term solution for LPR.
• Speech Therapy: For individuals with significant vocal cord irritation or damage, speech therapy may be recommended to help manage voice changes and improve vocal hygiene.

It is important to work closely with a healthcare provider to develop an individualized treatment plan for LPR, as the condition can be chronic and require ongoing management.