J Respir Med Lung Dis | Volume 4, Issue 2 | Review Article | Open Access

Mechanisms, Diagnosis and Management of Exercise- Induced Asthma

Nightingale Syabbalo^*

Department of Medicine and Physiology, Umtata Chest Hospital, South Africa

^*Correspondance to: Nightingale Syabbalo 

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Abstract

Exercise is one of the most common precipitants of asthma in clinical practice. In the general population the prevalence of Exercise-Induced Asthma (EIA) is reported to be 4% to 12%. The precise mechanisms for EIA are not clear, but are thought to be related to cooling and/or drying of the intrapulmunonary airways during exercise hyperpnoea. These effects may cause airway hyperosmolarity and release of inflammatory mediators from mast cells, eosinophils and basophils. Several mediators, including histamine, prostaglandins, leukotrienes and Th2 cytokines (interleukins) are known to cause airway smooth muscle contraction, microvascular leakage and oedema, and secretions. This would lead to airway narrowing and Exercise-Induced Bronchoconstriction (EIB). It has also been suggested that, both airway cooling with resultant vasoconstriction, may be followed by post-exercise rewarming hyperemia. This may result in bronchovascular engorgement and airway oedema that narrows the bronchial lumen causing symptoms of an asthmatic attack post-exercise. Exercise spirometry is the standard method for assessing patients with exercise-induced bronchoconstriction. Non-pharmacological preventive measures include avoiding known triggers, warm-up exercises before athletic activities, and choosing sports with low level of minute ventilation. Short acting inhaled β2-adrenoceptor agonists (SABAs) have been demonstrated to be the most effective against EIA, particularly in patients with airway obstruction before exercise. In some patients, a combination of an aerosol of a β2-adrenoceptor agonist and an inhaled anticholinergic agent ora cromone. Patients with severe EIA require addition of inhaled corticosteroids (ICSs), Long-Acting β2-Adrenoceptor Agonists (LABAs), or Leukotriene Receptor Antagonists (LTRAS). LTRAs and 5-lipoxygenase inhibitors only afford partial protection against EIA when administered as monotherapy. The future of interleukin-blocking monoclonal antibodies in affording bronchoprotection against EIA is still forthcoming.

Keywords:

Exercise-induced asthma; Inflammatory mediators; Exercise spirometry; Beta2- agonists; Inhaled corticosteroids

Citation:

Syabbalo N. Mechanisms, Diagnosis and Management of Exercise-Induced Asthma. J Respir Med Lung Dis. 2019; 4(2): 1045.