Advances in the diagnosis of exercise-induced bronchoconstriction Expert Rev. Respir. Med. Early online, 1–12 (2014) Oliver J Price 1 , James H Hull 1,2 and Les Ansley* 1 1 Faculty of Health and Life Sciences, Northumbria University, Newcastle, UK 2 Department of Respiratory Medicine, Royal Brompton Hospital, London, UK *Author for correspondence: Tel.: +44 191 243 7773 les.ansley@northumbria.ac.uk Exercise-induced bronchoconstriction (EIB) describes the post exercise phenomenon of acute airway narrowing in association with physical activity. A high prevalence of EIB is reported in both athletic and recreationally active populations. Without treatment, EIB has the potential to impact upon both health and performance. It is now acknowledged that clinical assessment alone is insufficient as a sole means of diagnosing airway dysfunction due to the poor predictive value of symptoms. Furthermore, a broad differential diagnosis has been established for EIB, prompting the requirement of objective evidence of airway narrowing to secure an accurate diagnosis. This article provides an appraisal of recent advances in available methodologies, with the principle aim of optimising diagnostic assessment, treatment and overall clinical care. KEYWORDS: airway dysfunction • airway-hyperresponsiveness • asthma • athletes • diagnosis • exercise-induced bronchoconstriction “If from running, gymnastic exercises, or any other work, the breathing becomes difficult, it is called asthma” Aretaeus (81–138 AD) [1]. Respiratory symptoms in association with exercise are reported frequently in both elite athletic and recreationally active populations. However, differentiation between a ‘normal’ physiologically appropriate and ‘abnormal’ pathophysiological response of the cardiorespi- ratory system is complex, presenting a poten- tial for misdiagnosis [2,3]. The most frequently encountered chronic medical condition in elite athletes is airway dys- function [4]. Depending on the population stud- ied and the diagnostic methodology employed, the estimated prevalence varies significantly. For instance, the prevalence in Olympians has been estimated at approximately 8% [4], whereas in high-risk populations (i.e., swimmers and cold-air athletes), the estimate is much greater (25–75%) [5–7]. In contrast, the prevalence of airway dysfunction in recreationally active indi- viduals has recently been identified at >13% [8]. Consequently, diagnostic accuracy in clinical practice is of fundamental importance to ensure the appropriate application of effective treatment. Airway dysfunction is a term used to describe the entities of exercise-induced bronchoconstric- tion (EIB), exercise-induced asthma, airway hyper-responsiveness (AHR) and/or asthma [7]. While often used interchangeably with exercise- induced asthma, EIB is the preferred terminol- ogy given exercise triggers bronchoconstriction rather than inducing the clinical syndrome of asthma [9]. Specifically, EIB describes the post exercise phenomenon of acute airway narrowing in association with physical activity [5,10]. Clini- cal characteristics of EIB often include dyspnea, increased perceived effort of breathing, chest tightness, wheezing, excessive sputum produc- tion and/or cough. In addition, individuals with the aforementioned symptoms may also report a reduction in physical performance and/or earlier onset of fatigue following a stren- uous bout of exercise [3]. The diagnosis of EIB in athletes has pre- sented difficulties in the past, predominantly because baseline spirometry possesses poor pre- dictive value [11] and primary care physicians rely heavily on self-reported respiratory symp- toms. However, it is now established that a symptom-based approach to diagnosis is imprecise as symptoms correlate poorly with objective evidence of airway narrowing [2,12]. As such, it is now recognized that an accurate diagnosis of EIB should be established through changes in lung function following a provoca- tive stimulus to the distal airways, rather than informahealthcare.com 10.1586/17476348.2014.890517 Ó 2014 Informa UK Ltd ISSN 1747-6348 1 Review Expert Review of Respiratory Medicine Downloaded from informahealthcare.com by 92.40.248.178 on 02/19/14. For personal use only.