help im scared..rash

[cjsmom24]

my  3year old daughter has been getting a rash for the last 24 hrs..it comes and goes..benadryl works and cream but it is coming back..it was bad to the point we went to the er but by the time the doc got there it was gone..it happens by her eye, top of foot,chest,tummy,butt and sometimes legs and her cheeks.it will come and a couple minutes later its gone..i havent changed soaps or anything different..any ideas?

[margypops]

Sounds like an allergy what does the rash look like is it streaks or blotches or single spots ?