Need 2nd Opinion...Please help! Really REALLY itchy chronic rash that comes and goes and has lasted for years

It is now 5:43am and I am awake bc the itchiness of this rash is just too much to sleep through.  
The rash began about 2 years ago...I guess I was under a bit of stress when I first broke out, but I'm not stressed now and I still have it.  Two dermatologists said I had a viral examthem and diagnosed me with pityriasis rosea...I think its pretty safe to assume its viral but as for the pityriasis rosea part...I'm not so sure.  I dont (nor did I ever) have a "mother patch" and my rash rally looks nothing like the pics of the condition on the web.  The rash began on my neck and a little on my my stomach, chest, back, and butt...it is EXTREMELY itchy and now basically shows up anywhere on my trunk.  On a bad flare up my back looks like something out of star trek or a bad horror flick...
The skin is raised and comes in various shapes of patches...the patches are never really circular..most are strangely-shaped, somewhat stretched-out patches...aka the marks tend to be longer and skinnier and non-symmetric.

It comes and goes multiple times throughout the day.  It usually flares up badly when I'm really tired and/or getting sick (usually if I wake up earlier than I usually would in the morning its worse than if I sleep longer).  Thus, it really seems to be immune-system-related...

Lately, it seems to be the worst on my back... it begins in a localized spot on my back and then climbs up or down my back and/or up along the sides of my torso...sometimes I get it on my butt too and my breasts and neck....
Help!

What can I do to treat this/stop it from flaring up/make it go away?

Do you think this is really viral? Does it seem like P.Rosea to you? (I have traveled to Africa and to other impoverished countries...I'm worried I may have contracted a strange infection of something that is hard to diagnose?)

Thank you so much for your time and consideration.  I would truly appreciate any input.

[Bhupinder Kaur, MD]

Hello,
From the symptoms it looks like hives. Hives (medically known as urticaria) are red, itchy, raised areas of skin that appear in varying shapes and sizes. They have a tendency to change size rapidly and to move around, disappearing in one place and reappearing in other places, often in a matter of hours.
I see that you are having the problem of chronic urticaria. It is defined as urticaria that persists for longer than 6 weeks. In most of the cases of chronic urticaria, the underlying pathology is idiopathic i.e it is not linked to any cause. It is essential to rule out the presence of serious illnesses of which recurring hives can be a symptom. Examples are hepatitis, hyperthyroidism, lymphomas, collagen vascular diseases, and cancers of the rectum, kidneys and gastrointestinal tract.

I feel that you should find out the cause of your chronic urticaria by ruling out the various conditions causing it. An allergist will be the best person to consult in this regards.
I sincerely hope that helps. Take care and please do keep me posted on how you are doing or if you have any additional doubts. Kind regards.