The presence of occipital hair in the pilonidal sinus cavity—a triple approach to proof
Hair in the pilonidal sinus is not growing within the sinus cavity, as hair follicles are not present there. Not few pilonidal patients do not have intergluteal hair, which is said to be the causative agent of folliculitis and pilonidal genesis. So, what is the real source of the hair forming the typical pilonidal hair nest?
A trifold approach was used: First, axial hair strength testing of pilonidal hair and body hair harvested from head, lower back (glabella sacralis), and cranial third of intergluteal fold. Hair strength match was compared clinically. Second, comparative morphological examination by expert forensic biologist of hair from sinus and dorsal body hair. Third, statistical Bayesian classification of every single sinus hair based on its strength was done to determine the most probable region of origin.
Using clinical hair strength comparison, in 13/20 patients, head hair is the stiffest hair, followed by intergluteal hair. Only in 6/20 patients, this is the case with hair from the glabella sacralis. According to comparative morphological comparison, a minimum of 5 of 13 hair nests with possible hair allocation examined contain hair from the occiput. In 5/18 nests, hair could not be determined to a specific location though. Statistical classification with correction for multiple testing shows that 2 nests have hair samples that are at least 100 times more probable to originate from head or lower back than from intergluteal fold.
We saw our null hypothesis that “hair in the sinus cavity is from the intergluteal region” rejected by each of three different approaches. There is strong evidence that occipital hair is present regularly in pilonidal sinus nests. We should start thinking of occipital hair as an important hair source for the development of the pilonidal hair nest.
KeywordsHair Pilonidal sinus Scalp Occiput Cut hair Electron microscopy Pathogenesis
Statistical analysis and calculations: AH, DD
Manuscript editing and interpretation of data: DD, FB, MML, FR, IS, AH, PM
Manuscript writing: DD, AH, DD, JG, FR, FB, MML
Graphic design: DD, AH, FB
Data acquisition: FB, AH, DD, JG, FR
Compliance with ethical standards
The ethics committee of the medical association of Niedersachsen, Berliner Allee 20, 30175 Hannover, Germany (Prof. Dr. med. Andreas Creutzig, chair), fully and unanimously approved the study based on § 15 of the Niedersachsen Medical Association’s professional code of conduct.
Conflict of interest
The authors declare that there is no conflict of interest.
- 2.Allen-Mersh TG (1990) Pilonidal sinus: finding the right track for treatment. BrJSurg 77:123–132Google Scholar
- 3.Anderson AW (1847) Hair extracted from an ulcer. Boston Med Surg J 36:74Google Scholar
- 4.Ardelt M, Dennler U, Fahrner R, Hallof G, et al. (2017) Adolescence is a major factor of sinus pilonidal disease - gender specific based investigation of case development in Germany from 2007 until 2015. Chirurg 88(11):961–967Google Scholar
- 6.Bosche F, Luedi MM, van der Zypen D, Moersdorf P et al (2017) The hair in the sinus: sharp-ended rootless head hair fragments can be found in large amounts in pilonidal sinus nests. World J Surg 42(2):567–573Google Scholar
- 11.Doll D, Luedi MM, Wieferich K, van der Zypen D et al (2015) Stop insulting the patient: neither incidence nor recurrence in pilonidal sinus disease is linked to personal hygiene. Pilonidal Sinus J 1:11–19Google Scholar
- 15.Favre R, Delacroix P (1964) Apropos of 1,110 cases of pilonidal disease of coccy-perineal localization. Mem Acad Chir (Paris) 90:669–676Google Scholar
- 16.Gosselink MP, Jenkins L, Toh JWT (2017) Scanning electron microscope imaging of pilonidal disease. Tech Coloproctol 21(11):905–906Google Scholar
- 22.Oien CT (2009) Forensic hair comparison: background information for interpretation. FBI Forensic Case Rev 11Google Scholar
- 25.Senapati A (2012) The management of pilonidal sinus disease. Contemporary Coloproctology Springer-Verlag London Ltd: 67–75Google Scholar
- 29.Warren JM (1854) Abscess, containing hair, on the nates. Am J Sci 28:113Google Scholar