It is difficult to diagnose any skin lesion without being able to see the lesions. Hence it is always better to consult a dermatologist for proper treatment.
Your rash could be the result of irritation, dermatitis (atopic, contact, and allergic), heat rash, excessive sweating, folliculitis or some medical condition like SLE. Hives are usually allergic (food, medication and insect stings) but may also be due to infections and stress. Many a times no specific cause for them is ever found. They usually go away on their own, but in a few serious cases, medicine might be needed. The most commonly used oral treatments are antihistaminics (such as cetirizine, loratidine, benadryl available over the counter).
You should consult a dermatologist who can determine the cause and prescribe appropriate treatment for it. In the meanwhile, you may try moisturizing lotions and calamine lotion for a soothing effect. You should avoid any cosmetics such as deodorants and use only mild hypoallergic soap.
Do keep us updated on the progress.
Was wondering if you had any luck with your skin and what the outcome is? I have what looks to be very similar to yours and exactly how you describe them too. I am seeing a dermatologist tomorrow. Be good to hear your feedback and how you getting on.
Hope you are getting better.