Does cough hypersensitivity syndrome differ from a chronic cough? Experts define it as a cough in response to a stimulus. Whereas persistent or chronic cough lasts for at least eight weeks.

The following chronic cough conditions may show hypersensitivity towards certain stimulants:

• Asthma (associated with cough)
• Chronic Bronchitis
• COPD
• Emphysema
• Pneumonia

Three good examples are: 

• cough variant asthma.
• idiopathic cough (typically lasts more than three weeks). 
• cough induction due to reflux.

Causes of Cough Hypersensitivity

There are various types of stimuli:

• Smoke
• Chemicals
• Dust
• Mites/Ticks
• Smog
• Fog
• Perfume

Cold weather, physiologic triggers, simply talking and laughing hard can also act as stimuli.

This often occurs due to one of three types of exposure:

• Chemical exposure - For instance, exposure to chemicals that are irritants.
• Thermal exposure - When you come in contact with temperature or heat is thermal exposure.
• Mechanical exposure - Applying high physical effort, which may lead to fatigue, is considered mechanical exposure.

Remember that stimuli, such as those listed above, do not necessarily make you cough every time. 

Symptoms of Cough Hypersensitivity

Initially patients' complaints of various sensations and symptoms undergoing hypersensitivity.

Some signs are

• Throat irritation
• Unexplainable sensation
• Difficulty in breathing
• Tickling
• Itchiness in the respiratory tract
• Laryngeal Paraesthesia 

Laryngeal Dysfunction in Hypersensitivity Syndrome: A Cross-Sectional Observational Study shows: deterioration of the vocal cords is quite common in CHS. 

Read this interesting yet powerful research study to learn about the Expert opinion on the cough hypersensitivity syndrome in respiratory medicine by the European Respiratory Society.

Tools to Measure Cough Hypersensitivity

Using cough frequency and cough reflex sensitivity tools can help measure the hypersensitivity.

Below are a few tools by name that were detailed in a study Hypersensitivity Syndrome: A Few More Steps Forward research:

• Tussigen inhalation challenge test 
• Hull Automated Cough Counter
• Leicester Cough Monitor
• VitaloJAK

Diagnosis of Cough Hypersensitivity Syndrome

Sadly, there is no specific diagnostic test or technique to detect this type of cough. Although, its diagnosis is not a big challenge. We might need special testing procedures in the future to find more accurate results.

A  physician may ask you a few questions about your condition. Describing your signs and symptoms in detail will help the healthcare provider assist you accordingly. 

It is essential to identify and point out the reason behind the trigger, whether it be chemical, physiological, thermal, or mechanical stimuli.  This information may be fundamental to diagnose the issue efficiently.

Often, simple cough sensitivity tests help in screening, such as by inhaling citric acid (vitamin C) or capsaicin (the active ingredient of chili pepper).

Treatment of Cough Hypersensitivity Syndrome

Involving treatment of speech pathology can aid in laryngeal dysfunction. 

Drugs such as amitriptyline and gabapentin treat chronic pain. They also act as antitussive agents. In addition, randomized clinical studies have demonstrated gabapentin medicine as effective against chronic coughing patients having laryngeal sensory neural damage.

Overview

To date, researchers have not produced as many studies about chronic hypersensitivity syndrome as would be ideal for substantially advancing the field. Therefore, more research is needed, especially in identifying approaches to improve outcomes of patients with cough hypersensitivity syndrome.

This insightful resource provides an overview of cough hypersensitivity progress at the Tenth London International Cough Symposium 2018.

Reference

1. Chronic cough hypersensitivity syndrome | Cough | Full Text (biomedcentral.com)
2. – A Major Advance in the Understanding of Chronic Cough | touch respiratory
3. clinical measurement is the key to progress | European Respiratory Society (ersjournals.com)
4. Drug-induced Cough - Hyfe Blog (hyfeapp.com)
5. Smoker’s Cough: Everything You Should Know - Hyfe Blog (hyfeapp.com)

Javeria Usmani