The Myth of Mild: Severe Exacerbations in Mild Asthma: An Underappreciated, but Preventable Problem

Asthma is a common, chronic inflammatory airway disease, characterised by unpredictable episodes of worsening symptoms, or exacerbations. Causes of asthma exacerbations include viral infections, exposure to allergen and air pollution, all of which increase the underlying inflammation that typifies asthma. Most (50–75%) patients are classed as having mild asthma, with symptoms that can be readily controlled with available inhaled medications. Paradoxically, for the past 30 years, the first treatment recommended in asthma management guidelines was short-acting β(2)-agonists (SABA), which not only have no anti-inflammatory properties but may, in fact, worsen inflammation. The Global Initiative for Asthma (GINA) 2019/2020 broke with this paradox by stating clearly that SABA should no longer be used alone as a reliever, for safety reasons. Instead, GINA now recommends an anti-inflammatory rescue/reliever approach for adult and adolescent patients, based on the combination of an inhaled corticosteroid with a rapid onset β(2)-agonist such as formoterol. This commentary highlights the fact that even patients with well-controlled mild asthma are at risk of severe, potentially life-threatening exacerbations, similar to those in patients with moderate or severe asthma, and therefore ‘mild asthma’, is a misnomer. The commentary describes the case history of a patient with mild asthma to illustrate how increasing use of SABA alone can worsen and prolong exacerbations when they occur. The author goes on to describe how the management of this patient’s exacerbation could have been improved, and provides up-to-date advice on broader aspects of the management of mild asthma and exacerbations, supported by the recent changes to the GINA recommendations.