White, Itchy Bumps

My daughter has been waking up screaming that she itches.  When I get up and turn on the lights she has white bumps, mainly on the top of her feet.  But lately they have been spreading up her legs, on her back, and now to her face.  It only happens a few nights a week, then quits for a month.  I would get up in the morning to schedule her an appointment with her doctor but within a hour or so, they are gone. The weird thing is, it happens only at 4 am!  It is not bed bugs and we have not been using any different types of laundry detergent.  I am so lost as to what this could be!

[Caryopteris]

I am unsure, but people online said ice packs help.  Seems like it would have to be having to do with perspiration or a contact dermatitis.  If there are any food allergies present, stopping the problem foods will lower the histamine load and may help.