It has taken me a while to narrow down an allergic reaction. For the past couple of weeks or so, my lips would dry up and they'd be itchy around my lips.
At first, I thought it was my toothpaste and dental floss that I was using while stateside. Nope.
Recently, I noticed that my lips would get itchy when I drank either Diet Coke or Diet Pepsi. The formulation of these two products are different, so I didn't think it was the type of pop.
Both drinks were in plastic bottles. I drank from plastic Diet Pepsi bottles in the States. I realized that I'm allergic when I drink directly from plastic bottles.
I'm not sure whether it'll be better if I pour the pop out of the bottle and into a cup to consume, or stick a straw into the bottle. There wouldn't be any plastic contact with my lips. I also don't know whether the plastic would seep into the pop. I have more tests to do.
The safe bet is to drink pop from cans or get fountain drinks. I haven't any issues with these formats.
I'm so glad that I have narrowed it down. It's such an odd allergy to have, but at least I know what to do when it happens. I have been using hydrocortisone cream around my lips to stop the itchiness and it works.