Bump. OP, if you’re still here, what was your diagnosis?

I’ve had a bad taste in my mouth for a few days and now white tongue today.

+1 on oral allergy syndrome. I started experiencing burning mouth / white tongue this year. Initially, my doctor treated it as oral thrush but told me to keep a food journal. Low and behold, turned out the symptoms always rushed back when I ate fennel seed or parsley. These being ingredients I used ALL. THE. TIME. Haven't had any issues since (sadly) cutting those out my diet.

I had something similar to this happened to me a few years ago. I suddenly became allergic to mangoes. They weren’t some thing I ate that often, maybe a handful of times a year, but I ate one one day and with an hours had extremely dry and peeling lips with hundreds of bumps all over them, my tongue was tingly and my mouth tasted weird.

I had no idea what was going on until I went on a huge Google rabbit hole and found out that some people are allergic to the oils on mango skin which can transfer to the flesh when you eat it. Apparently mangoes are in the same family as other common allergens like poison ivy and cashews. A few days of Benadryl cleared everything up and now I avoid anything with mango.

Just an example of something to look for in your recent diet, even if it’s something you’ve had many times before. Sudden allergies can pop up so weirdly.

I had a period of pronounced stress associated with work, and developed waxing and waning “burning mouth syndrome” at that time. Food tasted funny and my mouth had a burning sensation that got worse throughout the day. Dr. Google says that it is a thing that stressed out perimenopausal women get.... it was pretty miserable, but went away after 2 or 3 months.

Sounds like oral allergy syndrome. You can suddenly become allergic to something you've been exposed to a lot previously just like with ordinary allergies.