I've got a client I've been doing for years I've always used pink cream wax for everything and never had any problems, people have often said that's it's much less painful when they come to me - but this one particular lovely lady says that recently when I've waxed her upper lip the next day her lip is really sore for a few days after. She is having problems with her skin and thinks she's got an allergy to something she's using on her skin. She nearly ready to have her waxing done and I'm not sure what to suggest - help!!