Increasing Amount of Hair Reduction using Laser Correlates with Lower Probability of Recurrence in Patients with Pilonidal Disease

Background: Hair at the gluteal cleft plays a key role in the development and recurrence of pilonidal disease (PD). We hypothesized that more hair reduction achieved using laser could correlate with lower chance of PD recurrence.

Methods: PD patients who underwent laser epilation (LE) were categorized by Fitzpatrick skin type, hair color, and hair thickness. Photos taken at LE sessions were compared to determine hair reduction amount. LE sessions completed prior to the recurrences were recorded. Groups were compared using multivariate T-test.

Results: 198 PD patients had mean age 18.1 ± 3.6 years. 21, 156, and 21 patients had skin types 1/2, 3/4, and 5/6, respectively. 47 patients had light- and 151 had dark-colored hair. 29 patients had fine hair, 129 medium, and 40 thick. Median follow-up was 217 days. 95%, 70%, 40%, and 19% of patients reached 20%, 50%, 75%, and 90% hair reduction after mean LE sessions of 2.6, 4.3, 6.6, 7.8 sessions, respectively. To reach 75% hair reduction, patients require a mean of 4.8-6.8 LE sessions, depending on different skin/hair characteristics. PD recurrence rate was 6%. Probability of recurrence after 20%, 50%, 75% hair reduction was decreased by 50%, 78%, 100%, respectively. Dark hair and skin type 5/6 were associated with higher recurrence rates.

Conclusion: Patients with dark-color and thick hair require more LE sessions to achieve certain degree of hair reduction. Patients with dark hair and skin type 5/6 were more likely to recur; more hair reduction correlated with lower chance of recurrence.

Level of evidence: Level IV.