My daughter has tiny red bumps all over her body. there were no other symptoms. it just showed up. she says they do not hurt. no fever. slightly itchy

Difficult to say: Most rashes are not emergencies & get better on their own without treatment. If this came on suddenly & itches it could be a mild allergy to something she came in contact with. It could also be from a viral illness, especially if she has other symptoms of illness. Less likely is insect or bug bites, if it's widespread. Bites are usually more isolated. Age/weight-based Benadryl (diphenhydramine) can help w/ itch.