Q:For the last 2 days, my daughter randomly gets welts (raised tiny bumps red around the edges) come and go within minutes. What could this be? Allergies?  It appears on her legs  and arms. Today one on her chin, gone in 2 minutes. What do you think? She also has a nose cold. No fever.

A: It's most likely an allergic reaction to something she came in contact with.  A runny nose and no fever also go along with the probability of this being an allergic reaction.  At this time, I would recommend using an antihistamine like benadryl, claritin, or zyrtec.  If she were to get a lot more of these at the same time or develop wheezing or persistent cough, then she should be seen immediately by a physician.  The rash can come and go for 3-4 days before they stop.
The exposure can be food, chemicals, bug bites, or in some cases a virus.  But given that it's spring time, I would guess it's something she came in contact with or something she ate.