Patients with Persistent Cough Prone to Severe Asthma Presentation

Michael S. Benninger, MD

To establish a correlation between persistent cough and asthma diagnosis and severity, investigators from Cleveland found that patients with persistent cough tended to have a more severe asthmatic presentation.

This was especially prevalent in patients with a positive immunoglobulin E (IgE) allergy class test to cat and dog dander, house dust, or lamb’s quarter.

Michael S. Benninger, MD, Department of Otolaryngology-Head and Neck Surgery, Cleveland Clinic Lerner College of Medicine, Head and Neck Institute, led a team of investigators in establishing the correlation. They suspected cough to be a potential risk factor for severe asthma based on their previous study, ““The phenotypes of allergic asthma: Does in-vitro allergy testing help to predict poor responsiveness?”.

However, this was not included in the original study, which prompted them to conduct a separate, independent review which aided them in identifying patients with a potentially more challenging disease.

With asthma being cited as a common etiology for chronic cough in adult nonsmokers (24%-29%), Benninger and colleagues hypothesized that asthmatic patients who had or have persistent cough would have poorly responsive asthma.

The Methods

The team conducted a retrospective review on 701 patients who had positive IgE allergy in vitro blood testing between 2014 and 2018 and asthma diagnosis.

The data they collected included age, sex, diagnosis and age of diagnosis of asthma, IgE allergy test results, asthma treatment, smoking status and respiratory comorbidities such as cancer, and inflammatory diseases such as chronic obstructive pulmonary disease, as well as other systemic illness treated with steroids.

Treatment classes were also established, and included short-acting beta-2 agonists, long-acting beta-2 agonists, inhaled corticosteroids, anticholinergics, leukotriene modifiers, oral methylxanthines, cromolyn, immunomodulators, anti-IgE and oral corticosteroids, or a combination of these medications.

A myriad of primary IgE tests were included. Each IgE class response was evaluated using the median and interquartile range (IQR).

Benninger and colleagues evaluated 5 different outcome measures, namely 1) number of clinic visits due to asthma measured as an average clinic visits < or >4 per year for asthma care, 2) emergency department (ED) visits due to asthma measured as < or >1 a year due to asthma, 3) hospital admissions due to asthma measured as yes/no; 4) asthma treatment measured as < or >2 medica- tions needed to control asthma excluding rescue inhalers, and 5) use of corticosteroids measured as yes/no.

Lastly, persistent cough was identified by a description of cough lasting >8 weeks in one visit for adults or >4 weeks in pediatric patients or 2 or more diagnosis of cough from the same episode separated >8 weeks for adults or >4 weeks for pediatric patients.

The Findings

The data from the study suggested that patients with persistent cough and a positive IgE allergy class test noted earlier could have a more severe asthma presentation.

The investigators founf that for patients with asthma and persistet, positivity to lamb’s quarter 2.92 (95% CI 1.63, 5.22; P < .001) showed a higher likelihood of ED visits. However, allergens had no influence on ED visits for patients without persistent cough.

In the analysis of hospitalizations for patients with persistent cough, positivity to cat dander 2.09 (95% CI 1.03, 4.59; P < .05), lamb’s quarter 2.96 (95% CI 1.50, 5.79; P < .002), dog dander 3.37 (95% CI 1.54, 8.45; P < .004) showed a higher likelihood of hospitalizations.

For patients without persistent cough, positivity to cat dander 2.62 (95% CI 1.12, 6.88; P < .035) and dog dander 3.15 (95% CI 1.30, 8.81; P < .017) showed higher odds of hospitalization.

Benninger and colleagues believed these data could have potential long-term benefits in asthma prevention.

“This can help physicians identify high-risk groups and have more tailored treatments to prevent exacerbations and disease burden from one of the most bothersome symptoms for patients, cough,” the team wrote.

The study, “Persistent Cough as a Predictor of Poor Responsiveness in Asthma Patients,” was published online in The Laryngoscope.