answer:Purring is also a stress reaction. Does she have some sort of imbedded foreign object?Have you noticed an abscess or an abrasion? Is there a bald patch over the area? If your answer to all of these is no, then I wouldn’t worry, even if he is stressed in some manner, and is other wise okay. I’d see a vet, just to be on the safe side though. By the way, cute boy. Looks kinda like mine.