A pilonidal cyst may not cause symptoms. But if it's infected, the skin around the cyst may be swollen and painful. Symptoms of an infected pilonidal cyst include:  A pit near the top of the buttocks crease. Pain. Inflamed, swollen skin. Pus or blood leaking from an opening in the skin. An odor from draining pus. 
pilonidal cyst may cause symptoms  it's infected  skin cyst may swollen painful  symptoms infected pilonidal cyst include:  pit near top buttocks crease  pain  inflamed  swollen skin  pus blood leaking opening skin  odor draining pus
pilonidal cyst