with @PiggyOwner. Without a photo it is difficult to have any view. If, however, you are worried that your piggy is injured or in pain please seek immediate vet review and assistance. i posted two pics had to log on to computersorry to hear you are having problems . We could do with more info - what does the area look like ? is it a wound ?
Are you in the UK ?
There is a section on uploading photos in this thread - part 5
https://www.theguineapigforum.co.uk/threads/tutorial-videos.109353/
She had it on her foot first and then it spread to her mouth I guess from grooming but I will try and find a vet tommorrow