Help - baby chick keeps pecking around butt

[Mthawkins08]

We picked her up to check to pasty butt and gently wiped around with a Q tip. After putting her back down she's been pecking at her butt and doesn't seem to stop. Its becoming irritated. I can't find any cause for it either. Suggestioms? Im becoming concerned

 

[Mthawkins08]

She chips very loud when holding here. She had no problems till I checked her for pasty butt with a q tip