My 11yr old step daughter comes out in a red rash now and again, blotches of red which itch, what is the best way to find out what is going on?

Most likely an allergy.

You can take her to an allergy specialist for testing but before making that investment I'd try some home investigations i.e. make note of things she has eaten, places she has been, and insect bites etc prior to the rash appearing and look for commonalities.

Stress is also a possibility so see if she seems to be or have recently been upset before the rash occurs

I am starting with what she washes with, go away from these perfumed soaps, trying Dettol soap, just checked and the rash has completely gone, so guessing some allergy!! thanks for the advice, she did attend the dentist yesterday and was understandably upset!

Edited May 5, 201313 yr by dogpoo

While things she applies to the skin are possibles, so is food allergy. Also possible that it is an allergic reaction to some small insect bites, would suspect that particulalry ifg the rash occurs after playing outdoors.

It make take some trial and error but with patience you should be able to isolate what it is.

In the meantime, application of a steroid cream (something containing hydrocortisone betamethasone or pretty much anything ending in __asone) will give temporary relief while you are working out the cause.

I've gotten heat rash like that also, pharmacies has pills and oil for it

Stress is also a possibility so see if she seems to be or have recently been upset before the rash occurs

Thats good advice