Baby’s arms are bumpy & get super red

My baby will be 2 in September, and she has a checkup soon, so I will ask her doctor about this then, but in the mean time, I’m looking for mama advice.

If it’s warm/hot outside, the backs of her arms (from her shoulder to her elbow) get really red, hot to the touch, and are bumpy.

The bumps seem to be there always, but not the redness or heat. It doesn’t seem to bother her that I can tell, but I want to know if anyone else’s baby has had this, and if so, what is it?

We use free & clear detergent, aveeno baby wash, aveeno lotion, and no allergies that I know of.

Here’s a picture of the bumps. It’s not as red because she’s been inside and cool for s while.

The picture is loading funny. Let me know if y’all can or can’t see it.