When it's infected, a pilonidal cyst becomes a swollen mass (abscess). Signs and symptoms of an infected pilonidal cyst include:
- Reddening of the skin
- Drainage of pus or blood from an opening in the skin
- Foul smell from draining pus
When to see a doctor
If you notice any signs or symptoms of a pilonidal cyst, see your doctor. He or she can diagnose the condition by examining the lesion.