Pilonidalsinus

Pilonidal sinus is a chronic inflammatory condition of the skin and subcutaneous tissue in the sacrococcygeal region, typically presenting as one or more sinus tracts near the midline of the natal cleft. It most often affects young adults, particularly men, and is associated with a deep natal cleft, obesity, thick body hair, prolonged sitting, and prior trauma to the area.

The disease is believed to arise from hair penetrating the skin when hair follicles in the natal region become embedded, triggering a granulomatous reaction and secondary infection. Over time, sinus tracts may extend laterally and become recurrent and draining.

Symptoms include localized pain, swelling, redness, and drainage of serous or purulent material, sometimes with a foul odor. Recurrent abscess formation is common.

Diagnosis is clinical, based on examination. Imaging such as ultrasound or MRI may help delineate the extent of sinus tracts, particularly in recurrent or complex cases, and to distinguish from other conditions.

Treatment ranges from conservative management for asymptomatic disease to surgical excision of the tracts. Acute abscesses are usually treated with incision and drainage. For definitive management, procedures such as excision with primary closure, or flap techniques (e.g., Karydakis, Limberg) or minimally invasive methods (endoscopic pilonidal sinus treatment) are used. Healing by secondary intention is an option in some cases. Hair removal and laser epilation may reduce recurrence. Antibiotic therapy alone is not curative.

Recurrence remains a concern, particularly with inadequate excision or poor wound care. Prevention focuses on reducing hair in the natal cleft, good hygiene, weight management, and avoidance of prolonged pressure. Outcomes are generally favorable with modern surgical techniques, though recurrence risk persists.