Pilonidal Sinuses

A 45-year-old man sought medical advice after suffering for 6 months with recurrent pain and a purulent discharge at the sacrococcygeal region. Two weeks before this consultation, an abscess on the patient's right buttock had been drained by another physician. The patient had type 1 diabetes mellitus for 5 years; his medical history was otherwise unremarkable.

Pilonidal sinuses were diagnosed. This is a classic presentation of the disease, which most commonly occurs in the sacrococcygeal area.

The word "pilonidal" means a nest of hairs; it is thought that pilonidal sinuses are caused by penetration of local skin by growing hairs. The presence of hairs in the subcutaneous tissue predisposes the area to infection and abscess formation.

This condition is seen most commonly in dark-haired, hirsute men and often affects obese persons. The primary sinus may have one or more openings located strictly in the midline between the level of the sacrococcygeal joint and the tip of the coccyx. Secondary openings can occur on either side of the midline, often on the buttocks or in the perineum.

Treatment consists of incision and drainage of the abscess and excision of the sinuses. The wound should be gently probed to rule out additional cavities and to extract all collections of hair.