White spots on arm

[IDown4292]

Hi, my 3 month old starting getting these spots on his arm (pic attached). Noticed before or after bath time on the same arm. They tend to go away after about 1 hour. Anyone had this before?

Looks like hives/allergic reaction

Thanks. He has started teething and we tried a teething gel 3 days ago, and shortly after we noticed the first one. So we stopped using if after one bit, would it still be reaction from that 3 days later?