<s>[INST] My 15 year old son has a skin rash that has developed across his upper back, up his neck, is now creeping around to his chest & upper arms. He says they are unremarkable. No itching or sensitivity. We gave him oral Benadryl which seemed to slow the spreading, but that s all. Any suggestions? [/INST] Its difficult to comment onthe type of rash without looking at it. It may be allergic, viral or fungal infection. You can apply Betnovate GM and look at the response, if its not going a dermatologist must have a look at the rash. </s>