The common pilonidal sinus occurs in the sacrococcygeal region. It is more common when certain risk factors are present.


Typical location: 5 cm above the anus in the natal cleft in the midline


Risk factors for a pilonidal sinus:

(1) male gender

(2) age from puberty to 40 years

(3) abundant hair

(4) hair that is relatively stiff

(5) poor hygiene

(6) recurrent abrasion in the area (The condition was called "jeep" disease in World War II because of the frequency in Jeep drivers.)

(7) obesity


Additional factors to consider:

(1) history of a previous pilonidal sinus

(2) moisture from sweat or other source


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