When to Seek Urgent Care
Seek prompt medical care for a painful swelling, pus or bleeding at the top of the buttock cleft. Fever, spreading redness or feeling unwell may mean an abscess. Do not squeeze or try to drain it yourself.
Understanding the Condition
A pilonidal sinus is a small opening or tunnel beneath the skin near the tailbone, usually in the cleft between the buttocks. Hair and debris can become trapped and lead to infection.
Some sinuses cause no symptoms. Others produce repeated swelling, pain or discharge. Pilonidal disease is separate from an anal fistula, which usually opens closer to the anus.
How It Is Assessed
The surgeon examines the openings, swelling, scars and the extent of affected tissue. Previous drainage or surgery, repeated infections, work, sitting and wound-care support all influence the plan. Imaging is not routinely needed unless the diagnosis or extent is uncertain.
When Is Surgery Considered?
An acute abscess is treated by incision and drainage. Antibiotics may be added for surrounding skin infection or another clinical reason, but they do not replace drainage.
A symptom-free sinus may need only observation and clinician-guided skin and hair care. Persistent discharge, repeated abscesses or recurrent disease usually leads to discussion of a planned procedure.
Procedures, Surgery and Important Risks
Limited or endoscopic treatment cleans and treats the tract through small openings and suits selected, less extensive disease. Excision removes affected tissue. The wound may be left open to heal or closed using an off-midline technique or flap. If a wound is closed, keeping the scar away from the deep midline cleft lowers wound problems and recurrence.
Risks include pain, bleeding, infection, wound separation, slow healing and recurrence. The most suitable operation depends on disease extent, previous treatment and the practical demands of wound care.
Recovery and Follow-up
An open wound may need dressings for several weeks. A closed wound may heal sooner, although infection or separation can delay recovery. Confirm who will provide dressings and when sitting, driving, exercise and work can resume.
Follow instructions about washing, dressings and hair management. Seek advice if pain increases, discharge changes or fever develops. Do not shave the area unless your clinician has advised a safe method.