Headliner in Physiology and Management of Childhood Asthma: Hypothalamic-Pituitary-Adrenal Axis

Abstract

Asthma is the most common chronic inflammatory disease of children. Inhaled corticosteroids (ICS) are the cornerstone of asthma therapy which are the most effective, commonly used treatment of persistent asthma. Mostly, studies on the relationship between asthma and cortisol have focused on side effects of treatment. Recently, asthmatic patients not treated with ICS have been reported to have an attenuated activity and/or responsiveness of their Hypothalamic-Pituitary- Adrenal (HPA) axis. Moreover, it has been proposed that asthma worsening with stress may be due to a dysfunctional HPA axis, or cortisol insensitivity due to chronic psychological stress through impaired glucocorticoid receptor expression or function. Although long-term ICS treatment might produce adrenal suppression or iatrogenic Cushing syndrome, improvement of adrenal function has also been detected in some of asthmatic cases. Thus, the response scheme of HPA axis still contains undiscovered features in asthma. The management of asthma can be improved by increasing knowledge on the role of HPA axis in asthma pathophysiology. The risk for side effects of ICS can be minimized through increased awareness, early recognition of at-risk patients and regular patient follow-up. This review was written to draw attention to the role of HPA axis in both asthma and its treatment and to illustrate a follow up algorithm of HPA axis in the management of asthma.

Keywords: Adrenal insufficiency; Hypothalamic-Pituitary-Adrenal axis; adrenal suppression; iatrogenic Cushing syndrome; inhaled corticosteroids..