My oldest had it happen, had just a little circle of baldness at the back of his head. Did nothing, he’s now 6 with a full head of hair
It's normal, the hair will grow back by itself, you don't need to do anything to help it grow
My first baby had his until after he turned 1 and now has a great head of hair My 3 month old also has it. It’s very normal and will grow out on its own
Following as mine has the same, she self soothes in her crib by shaking her head so is really bald! X