I've checked online and can't find anything quite like this. My first baby had no hair loss at all after she was born with a full head of long, thick hair.
Now I have a 3 month old boy who was also born with a head of full, thick hair. Recently, it developed a 1/2 inch ring all the way around the middle of his head where it seemed the hair had fallen out. I assumed this was where his scalp was growing and the hair just hadn't had time to fill in the new skin yet. Now the ring is still there, only one whole side of his head is balding. There are some lighter, shorter hairs growing all over that half of his head, but they are rougher than the long, soft brown hair on the back, top and other side. The hair only seems to be falling out of one side.
My first thought was that he was laying on that side because until now he did prefer to lay only on one side because he likes to face me in bed. Then I realized that the side he's balding on is NOT the side he usually lays on. It's the side he avoids. The bald area has no redness or flaking. It doesn't seem to have anything wrong with it at all other than that the hair seems to be falling out. And, like I said, it's not totally bald. There are thin, light hairs which feel a bit like straw. They are about 1/2 inch in length whereas his brown hair is about 1 inch long.
Anyone experience anything like this? Please tell me it's normal. I was hoping he would lose it all like normal newborn hair loss, but it has been a few weeks now and still, just this one side. He looks like he has a mohawk from just that side as if I buzzed that side of his head and left the rest.