Rash and blisters

I went camping over a week ago. It was around 100F.  I have rash on my arms, back and legs. In addition, I have big blisters on my hand. Rashes seem to be going away, however blisters and bumps aren't. I would like to know whether it's a heat rash or possibly poison oak or ivy. I'm attaching pictures of my hand. For the past week I have been taking Over-the-counter Benadryl tablets ( Diphenhydramine 25mg) 6 tablets a day, benadryl cream, and Hydrocortisone.
Thank you

p.s. Pictures in this link
https://picasaweb.google.com/SeidoLA/SkinRash?authkey=Gv1sRgCOLV4L6R09zYRw

[Bhupinder Kaur, MD]

Hello,
It can be due to contact dermatitis, phytodermatitis, Pseudo or Drug induced PCT,Epidermolysis bullosa aquisita or porphyria cutanea tarda. If it is itchy then rash due to contact dermatitis with poison ivy can be considered.

Please get it examined from a dermatologist to confirm the diagnosis.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.