Systemic safety of serial intralesional steroid injection for subglottic stenosis

Serial intralesional steroid injection (SILSI) has recently been proposed as an effective scar-modifying therapy for subglottic stenosis (SGS). We aimed to explore the systemic absorption of steroid following SILSI and to characterize the magnitude and chronicity of any effect observed. Specifically, we aimed to show that any effect resolves prior to the next intralesional injection.

Prospective, observational pilot study.

Patients were injected intralesionally with 40 to 200 mg triamcinolone. Serum cortisol, as well as white cell counts and inflammatory markers were measured at day 0 (baseline), 1, 7, and 28. Salivary cortisol was measured at baseline and for 7 consecutive days following injection.

Six patients with idiopathic SGS were recruited. At baseline, serum cortisol measured 284.0 ± 61.4 nmol/L and fell significantly to 15.5 ± 4.3 nmol/L 1 day following triamcinolone injection (P = .03). At day 7, serum steroid levels showed significant recovery to 221.8 ± 78.9 nmol/L (P = .03) and further rose to 279.5 ± 29.9 nmol/L at 28 days (P = .07). Salivary cortisol exhibited a similar pattern with significant recovery by day 6 (P = .04) and suggestion of exponential clearance of triamcinolone systemically. White cell counts were also affected by systemic absorption of exogenous steroid. No significant change in inflammatory markers was observed.

Our findings demonstrate systemic absorption of steroid following SILSI, with acute hypothalamic-pituitary-adrenal (HPA) axis suppression. However, normalization of HPA axis function by day 7 suggests that although acute steroid side effects should be discussed with patients, no cumulative systemic steroid side effect would occur with serial injections.

2 Laryngoscope, 129:1634-1639, 2019.