Evaluation of the pituitary-adrenal axis function in patients on topical steroid therapy 皮质激素抑制垂体-肾上腺轴功能
In this issue of the JAAD, Kerner et al report blunted adrenal responses after the use of topical corticosteroids. While it is reassuring that laboratory values remained within the normal range in this particular study, the blunted responses serve as a reminder that systemic absorption of topically applied corticosteroids can have systemic implications. Topical corticosteroids can cause iatrogenic Cushing disease and adrenal suppression. 1-5 Those at greater risk for medically significant adrenal suppression include infants and young children, those with an impaired cutaneous barrier, and those in whom highly potent corticosteroids are applied over large areas or under occlusion. Highly vascular areas, such as the ear canals and diaper area, have been associated with enhanced systemic absorption. Practical guidelines to reduce the effects of systemic absorption include pulse application of more potent corticosteroids (weekends only or 2 weeks on/1 week off), medication holidays, use of the minimal effective strength and dose of medication, and the use of steroid-sparing agents. We must be mindful that many patients with steroidresponsive dermatoses remain under-treated, and our role is to optimize patient outcomes while minimizing the risk of complications. The following commentary by Lynnette Nieman, MD, of the National Institutes of Health, focuses on topical corticosteroids and their potential to induce adrenal suppression.
Topical corticosteroids can be absorbed percutaneously in sufficient quantities to cause systemic adverse effects. Suppression of the hypothalamic pituitary adrenal (HPA) axis has been reported following topical corticosteroid therapy. 1-3 We measured cortisol response to 1 g of adrenocorticotropic hormone (ACTH) in patients receiving topical corticosteroids for dermatological disorders.
Topical steroids induced some degree of cortisol suppression in 38% of patients, in line with reported suppressed ACTH secretion by inhaled steroids and intra-articular injection. An increase in steroid potency was linearly related to a decrease in cortisol levels. When adrenal insufﬁciency or acute adrenal crisis is suspected during topical corticosteroids, a morning cortisol level is the most cost-effective means of diagnosing clinically signiﬁcant suppression. The 1-g ACTH test is a more sensitive means of assessing the HPA axis. A blunted cortisol response to ACTH and suppressed fasting cortisol levels may indicate adrenal insufﬁciency, which can be conﬁrmed by stimulation studies with the overnight metyrapone test.
In conclusion, although clinically signiﬁcant systemic absorption of topical glucocorticoids is uncommon, it has important deleterious consequences. Mindful clinicians will consider this possible complication, particularly in high-risk patients.