Suggest Treatment For Itchy Rash On The Legs And Arms

I have had a itchy skin rash on my legs and arms for over a week, i thought it might be the baby oil that I was using for dry skin, however i stopped that last weekend, I started drinking coconut water two weeks ago, i stopped drinking that last monday, thinking it might be that. I still have the rash and it is worse in the evening and at night.

Should i see my doctor, i have been taking anti-histimine, but it does not seem to be working.