Update: Management of co-morbidities in asthma

Posted on: 31 Mar 2017
 

Module summary

This module will highlight the importance of the early recognition of comorbidities in patients with asthma.

Learning objectives

After completing the module, you should be able to:

• Describe the major comorbidities associated with asthma
• List common tests to identify and assess comorbidities
• Discuss how comorbidities can contribute to the pathogenesis and poor control of asthma
• Communicate the benefits of diagnosing and treating comorbidities in overall asthma management
• Define the key principles of treating difficult asthma, for instance when to make a specialist referral

Introduction

Patients with asthma often present with various comorbidities which can lead to poorer outcomes of their condition, through factors such as a misdiagnosis or misinterpretation of symptoms, and this can complicate management.1-3

For example, symptoms such as increased breathlessness may be misattributed to a patient’s asthma when they are, in fact, caused by a coexistent condition such as chronic obstructive pulmonary disease (COPD). Some comorbid conditions can alter the phenotype, or the way in which asthma presents, making it harder to diagnose. For example, the coexistence of nasal polyps in asthmatics has been linked with aspirin intolerance and a more severe asthma phenotype.1 A misdiagnosis may also occur if a patient has a coexistent condition, e.g. a psychological morbidity which causes them to incorrectly perceive their asthmatic symptoms. Clearly, the failure to correctly diagnose comorbidities can result in the inappropriate management of a patient’s asthma.1,3-5

The prevalence of comorbidities may be higher in difficult asthma, a subgroup of patients defined by the BTS/SIGN 2016 asthma guideline as having persistent symptoms and/or frequent asthma attacks despite treatment with high-dose therapies or continuous or frequent use of oral steroids.6

Difficult asthma can greatly affect a patient’s quality of life. Patients experience frequent exacerbations that can result in many days of absence from work or school. Difficult asthma increases the likelihood of hospital admission by 20 times and accounts for 50% of asthma-related expenditure in the United Kingdom.5,7

Recognising the role of comorbidities in difficult asthma, the BTS/SIGN 2016 asthma guideline recommends checking for such conditions as part of the evaluation process in a patient with difficult asthma.6

List of abbreviations
ACO	Asthma–COPD overlap	ICS	Inhaled corticosteroid
BMI	Body mass index	LAMA	Long-acting muscarinic antagonist
BTS/SIGN	British Thoracic Society/ Scottish Intercollegiate Guidelines Network	OSA	Obstructive sleep apnoea
COPD	Chronic obstructive pulmonary disease	PEF	Peak expiratory flow
CT	Computed topography	PPI	Proton pump inhibitor
ECG	Electrocardiogram	RCPH	Royal College of Paediatrics and Child Health
FEV1	Forced expiratory volume in 1 second	SABA	Short-acting beta agonist
GINA	Global Initiative for Asthma	TLCO	Transfer factor for carbon monoxide
GORD	Gastro-oesophageal reflux disease