Features

• A pilonidal cyst first appears as a small skin indentation and may not even be noticeable, states the Mayo Clinic. The cyst will swell, leak blood or pus and be painful if it becomes infected.
  
  

Causes

• When stray hairs are forcibly pressed down into the skin, the body may view the hair as an unknown substance and develops a cyst to isolate it. Skin chafing, tight clothing or prolonged sitting can cause hair to dig into the skin.
  
  

Time Frame

• Pilonidal cysts form most often in teenagers and people in their twenties. The condition seldom occurs after age 30, reports the University of Michigan Department of Surgery.
  
  

Treatment

• Antibiotic medications are prescribed to treat infected pilonidal cysts and a doctor will remove any blood or pus. If the cysts continue to come back, they can be surgically removed.
  
  

Warning

• If a pilonidal cyst infection is not permanently treated, a person is more likely to get squamous cell carcinoma, a form of skin cancer, states the Mayo Clinic.