It is a small abscess or wound having single or multiple openings
pilonidal sinus
Pilonidal sinus is a condition characterized by a small abscess or wound, often with single or multiple openings, typically located over the tailbone at the top of the buttock cleft (natal cleft). While the natal cleft is the most common location, it can also occur in other areas like the armpits or finger webs. The primary cause is ingrown hair. In some hairy and obese individuals, hairs in the natal cleft can penetrate the skin through a small opening. The hair, being a foreign substance, triggers pus formation, eventually leading to an abscess or sinus.
Pilonidal sinus is a bothersome condition characterized by recurring swelling, pus drainage, and subsequent subsidence. While primarily a subcutaneous lesion, it can sometimes be a consequence of tuberculosis of the spine. Therefore, doctors may recommend X-rays of the lower spine (lumbosacral spine) to rule out any vertebral pathology.
Surgical intervention is the primary treatment for pilonidal sinus, as medical management is generally ineffective. Due to the high recurrence rate, minimally invasive procedures like Ksharasutra treatment or laser surgery are often preferred.