Elevated Salivary Cortisol Levels Caused by Lip Balm Use

Endogenous Cushing syndrome is a disorder characterized by cortisol excess, with an incidence of 0.7-2.4 million of the population per year. ¹ Approximately 10% of new cases each year affect the pediatric population.² The current recommendations for assessment of Cushing syndrome include either 24 hour urine free cortisol, dexamethasone suppression testing, or measurements of late night salivary cortisol levels.³ Given its relative ease of collection and storage, as well as its high sensitivity and specificity, late-night salivary cortisol levels have become the most popular method for initial testing. Despite its sensitivity, testing is susceptible to false positives primarily via contamination from topical steroid ointments and creams. This case presents a pediatric patient with elevated salivary cortisol levels referred for evaluation of Cushing syndrome found to be secondary to an over-the-counter lip balm containing 1% hydrocortisone.

Case Description :

A 19-year-old previously healthy female presented to her pediatrician for evaluation of fatigue, hair loss, palpitations, and unexplained weight gain. Though initial workup including thyroid function studies were normal, evening salivary cortisol and ACTH levels were obtained for evaluation of Cushing syndrome. ACTH levels were noted to be within reference range, but salivary cortisol levels at 11 PM two consecutive nights were significantly elevated at 16.81 mcg/dL and then 29.87 mcg/dL (reference range for 11 PM is < 0.09 mcg/dL). To further evaluate we performed 24-hour urine free cortisol and low dose dexamethasone suppression testing which were not consistent with Cushing syndrome. Interestingly, salivary cortisol levels collected at 11 PM for 3 consecutive nights showed persistently elevated salivary cortisol >1.00 ug/dL.

Discussion :

With all testing inconsistent with diagnosis of Cushing syndrome except for salivary cortisol, concern arose for sample contamination. An in depth review of the patient’s topical cosmetics was completed and revealed an over-the-counter lip balm containing 1% hydrocortisone which had been recommended 3 years prior for management of dry lips during acne vulgaris treatment with isotretinoin. The patient was asked to discontinue use of the lip balm for three weeks, after which salivary cortisol levels were repeated at 11 PM over three days and were now within reference range and not consistent with Cushing syndrome. Thus, the diagnosis of Cushing syndrome was excluded and the etiology of elevated salivary cortisol levels was attributed to lip balm use.