Conversation: The conversation between human and AI assistant.
[|Human|] My nearly three-year-old son has a bright red blotchy rash that comes and goes on different parts of his body the last two days.  It is all up and down the sides of his face and behind the ear.  Plus, his chest, entire back and his legs.  It seems to bother him sometimes and sometimes it doesnt at all.  He was unusually fussy going to bed last night, but once he was asleep he stayed that way until morning.  He does not seem feverish except the rash feels warm to the touch.  Can you shed any light on this for us?  Thanks.
[|AI|]  From what you are describing, these rashes are probably wheals - urticaria in medical language. They come in response to some form of allergy - against food, against contact ants like soaps, body creams, etc., against cold water, against insect bites, etc. They will be warm, and they will typically come and go for several days. Give him an anti-allergic medicine like loratadine. You may also apply Call Chat Doctor.  In rare cases, he may need an oral steroid medication. Flags would be raised if the rash isn't better in a week, if there is bleeding from the skin due to itching, if he has any general symptoms like fever, difficulty in breathing, cloudy urine or fast heart-beat, or if he gets extremely itchy and cannot sleep or eat or do any normal activities. In that case, you may go to the ER. Otherwise, consult his pediatrician within a few days.