Objective: To study the incidence and causes of pilonidal sinus in Turkish soldiers.
Design: Open study by questionnaire.
Setting: Military and University hospitals, Turkey.
Subjects: 1000 soldiers who presented for their first medical examination.
Main outcome measures: Correlation between factors known to be associated with pilonidal sinus, and incidence of pilonidal sinus.
Results: 88/1000 soldiers had pilonidal sinuses; in 48 they were symptomatic and in 40 asymptomatic. The factors associated with the presence of a pilonidal sinus were: family history of pilonidal sinus (18/88 compared with 32/912, p < 0.0001); obesity defined as weight over 90 kg (34/88 compared with 32/912, p < 0.0001); being the driver of a vehicle (58/88 compared with 308/912, p < 0.0001); and the incidence of folliculitis or a furuncle at another site on the body (22/88 compared with 64/912, p < 0.0001).
Conclusions: Pilonidal sinus is an acquired condition, penetration of hair is the main cause, and the disease can be prevented if the aetiological factors are understood.