question about a preauricular sinus

i am 32 years old. i had a preauricular sinus cyst removed about 6 months ago. previously, this had become infected twice. once about 10 months ago and before that about 7 years ago. both times i had the infected area just in front of the cyst where the swelling and fluid was lanced open and drained. after this the area always healed without incident. on the advice of my doctor i had the cyst removed to prevent future infection. immediatly following the surgury i had another infection that did not respond to antibiotics as with the other two infections. i had to have another minor
procedure to drain and pack the abcess (abscess) again. also healed. this was about 3 months ago. the area has once again become inflamed though not as bad. my doctor told me that this may happen and that he may have to go in and
remove more tissue/track or cyst ( this is all kind of confusing, im not sure about how the cyst relates to the track
ect.ect.) i have had the fluid/puss cultured both times. no bacterial growth. My question is why is this getting inflamed again after the surgury. i do ride a motorcycle and where a helmet although i try to be carefull. the incision was healed
although still a little soft. could this be the reason for the new infection or is this just a recuurent issue. i was under the impression that once the cyst was removed that the infections were over although my doctor says that these
tend to be reoccuring, sometimes after surgury. could this be due to incomplete excision of the cyst/track. also i never
run a fever with these. Is this just like a big sebacious gland?