Do i need a prescription for my rash?

Exam: A full medical exam is needed to make a proper diagnosis. If you have poison ivy, calamine lotion, oral antihistamines & cool, wet compresses should help. However, even though poison ivy seems like a real possibility as I have suggested you need to be examined by a physician for a proper diagnosis to be made.

Possibly: It is likely a contact dermatitis such as poison ivy but there are other possibilities. See your primary care doctor or a dermatologist.