Differences between male and female patients with pilonidal disease

Background: Pilonidal disease begins in puberty when males and females have different sex hormone expression. We hypothesize that sex differences can lead to clinical differences in pilonidal disease. Methods: Patient demographics, Fitzpatrick skin type, hair characteristic, presentation, pain score, recurrence were recorded 2019-2022. All patients underwent regular epilation+/-pit excision. Excised pits were stained for estrogen receptor, progesterone receptor, and androgen receptor. Results: 237 patients (110F, 127 M) were followed 351+327days. Females present younger than males (17.5 + 3.9 vs.18.4 + 3.6years). While no sex-related differences noted in recurrence rate (4.5% vs.7.9 %) or skin type, there were significant sex-related differences in hair amount, thickness, density, and color. More males had granuloma than females (34% vs.12 %): 63 % granuloma were located left of midline, 30 % right, 7 % center. More males than females presented with drainage (67% vs.35 %). Significant differences were noted in patientreported pain: Females' mean initial pain score was higher than that of males' (5.6 + 2.5 vs.4.7 + 2.2). 35 % females had menstruation-related gluteal cleft pain (MRGCP), not associated with recurrence or pads/tampons use. Females on contraceptives (15.5 %females) had lower pain score than those who were not (3.9 + 2.7 vs.5.8 + 2.4) and none of these females reported MRGCP. Patients with drainage had lower pain score than those without (4.5 + 2.4 vs.5.8 + 2.2). Excised pits from females with MRGCP had higher proportion of fibroblasts stain positive for estrogen receptor and androgen receptor compared to those without MRGCP (28.4 %+9.0 % vs.14.4 %+6.5 %, 18.0 %+11.7 %vs.6.9 %+9.0 %, respectively). Conclusions: Male and female pilonidal patients differ in pain intensity, drainage, and granuloma formation. More fibroblasts with estrogen receptor and androgen receptor expression is a potential mechanism for MRGCP that is ameliorated by contraceptive use.