Pilonidal disease is a skin condition at the top of the buttock crease where hair works its way into the skin and causes inflammation, a sinus or an abscess. It is most common in young men with dense body hair and in people who sit for long periods.
Key symptoms
- Pain and swelling at the top of the buttock crease
- Drainage of pus or blood
- Pain when sitting
- Repeat episodes over months or years
What you find on exam
- Small midline pits in the buttock crease
- Tender, red, fluctuant swelling just off the midline (abscess)
- Sinus tracts with hair inside
- Fever and spreading cellulitis in severe cases
Tests
- Diagnosis is clinical
- Culture of pus if recurrent or severe
- Ultrasound or MRI if the disease is complex or its extent is unclear
Treatment basics
- Acute abscess: incision and drainage, ideally off the midline
- Antibiotics only for cellulitis, weak immunity or systemic signs
- Wound care with packing or dressings, plus sitz baths
- Surgery for chronic disease: excision, flap or minimally invasive procedures
- Hair removal (laser or shaving) and good hygiene to prevent recurrence
Red flags
- Fever, spreading redness or signs of sepsis
- Large abscess or quickly worsening pain
- Wound that has not healed months after surgery
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.