Redness on mouth palette

B

Would anyone know what this might be? It’s a bad photo sorry. The red spot on the roof of mouth.

We have a dr appointment tomorrow but I just seen this now and it’s like a red area on the roof of the mouth. My baby is still normal self although has had a small cough for almost 2 weeks now. Has anyone’s baby had this? Baby is 1 I do give food appropriate for age so I’m scared my baby might be allergic to something maybe.

Thanks for any help.