Ultrasound-guided injection of intralesional steroids in acute hidradenitis suppurativa lesions: A prospective study.

The management of hidradenitis suppurativa (HS) flares with intralesional steroids lacks strong scientific evidence but limited data suggest that it may be useful. The objective of this study is to assess the clinical and ultrasound responses of HS flares to ultrasound-guided injections of intralesional triamcinolone (40 mg/ml) with a dilution 1:4 versus 1:2 at 30-day (t1), 60-day (t2), and 90-day (t3) follow-up. We recruited patients with ≤3 acute lesions, unresponsive to topical therapy. At baseline we assessed lesions clinically and by ultra-high frequency ultrasound (48 or 70 MHz) and randomly performed an ultrasound-guided injection of triamcinolone. Assessments were repeated at t1, t2, and t3 follow-up, re-injecting the lesion in the case of no or partial response. We treated 49 lesions: 38.8% showed improvements at t1; 46.9% at t2; 6% at t3; and 8.3% showed no clinical and ultrasound improvements. Long-term follow-up data confirmed a statistically significant reduction in Visual Analogue Scale (VAS)-pain, Dermatology Life Quality Index (DLQI), and HS-Physician Global Assessment (HS-PGA), as well as edema and vascular signals. No adverse effects were reported. Our study suggests that ultrasound-injections with a 1:2 dilution are beneficial for HS flares that do not respond to topical treatment and should be included in the therapeutic algorithm.