01015 Baseline Sleep Variability and Trajectories of Pain and Pruritus in Patients Receiving Surgery for Hidradenitis Suppurativa: A Pilot Study

Abstract Introduction Sleep plays a role in inflammation regulation and wound healing, and sleep disturbance is common in patients with Hidradenitis Suppurativa (HS), a chronic inflammatory skin condition. Sleep has been linked to pain and pruritus in HS cross-sectionally, however it is unclear how sleep variability relates to post-surgical symptom trajectories for patients undergoing surgical excision. This study characterized baseline sleep variability and analyzed predictors of post-surgical change in patients undergoing surgical excision for HS. Methods Participants (N=18; mean age=32.17, 88.89% female) provided data at five time-points: pre-surgery, and 2, 6, 12 and 26 weeks post-surgery. A subset (N=16) completed 7-day sleep diaries pre-surgery; intraindividual standard deviations (SD) in Total Sleep Time (TST), Bedtime, and Wake Time were calculated. Outcomes were the PROMIS Sleep Disturbance Short Form 4a, Brief Pain Inventory (Pain Severity and Interference scores), and a 7-day average Itch Intensity visual analog scale assessed at all time-points. Spearman correlations and linear regressions tested associations between baseline sleep variability and longitudinal symptom trajectories (within-person slope). Results Participants demonstrated high daily sleep variability: TST mean (M)=6 hours 28 minutes, within-person SD M=135 minutes; Bedtime SD M=90 minutes; Wake Time SD M=78.4 minutes. There was a trend between TST variability and pain severity (p=0.05). Longitudinally, sleep disturbance, pain severity, pain interference, and itch intensity significantly improved. TST, Bedtime and Wake Time variability all correlated with itch intensity slope (p< 0.05). In a linear regression including Bedtime and Wake Time variability and controlling for baseline itch intensity, Bedtime variability significantly predicted itch intensity slope (F(3,12)=7.027, p< 0.01, adjusted R2 =0.55). Conclusion To our knowledge, this is the first study to evaluate sleep variability and its association with symptom trajectories in patients with HS following surgical excision. Even within this small pilot sample, participants exhibited marked variability in sleep timing and duration. Greater baseline irregularity was robustly associated with poorer pruritus improvement post-surgery. These preliminary findings highlight pre-surgical sleep variability as a promising and potentially modifiable target for optimizing postoperative symptom outcomes in patients with advanced HS. These results also underscore the need for larger, confirmatory studies. Support (if any) This work was supported by the Blaustein Pain Research Endowment Fund.