The condition is seen much more frequently in men than women, usually after puberty and before the fourth decade of life, and is characteristically seen in dark-haired individuals rather than those with softer blond hair (Oldham). Patients complain of intermittent pain, swelling and discharge at the base of the spine but little in the way of constitutional symp- toms. There is often a history of repeated abscesses that have burst spontaneously or which have been incised, usually away from the midline. The primary sinus may have one or many openings, all of which are strictly in the midline between the level of the sacrococcygeal joint and the tip of the coccyx.