My baby has white and yellow patches on her lower lipppp

Zainab

Hellooo, so my baby has been having these white and yellow patches on her inner lower lip and i am seeing this for the first time. She has also been rejecting food recently and acting a bit cranky.

What could this be? How can i treat this? What could have possibly caused this? I am so confused

Ps. Sorry for blurry pictures, my baby wont stay still. 🤣😭