I'm having the same thing and though I don't have a rash, my skin is red tinted and when you press on it, you can see it go white, it's my histamines. I got my blood work bad and there were no raised eosinophils, which usually indicates an allergic reaction, but my hematocrit was a little high, my WBC was low normal, rbc high normal and platelets definitely high. Of course, the doc told me my blood work was normal but I read that if your hematocrit gets high it can make you itch like that all over, especially after a bath. You might want to get some basic blood work done if it doesn't go away. Because of the nausea they are doing an endoscope for tropical/celiac sprue.
Also, high bilirubin from liver, and kidneys make you itch like that. It's extremely aggravating. Nothing helped me but my pain meds and IV antihistamines at one point.
The oatmeal baths everyone recommended did help. And if you get desperate ben gay will turn the itch to burn! I hope you feel better soon!
--Doctors are men who prescribe medicines of which they know little, to cure diseases of which they know less in human beings of whom they know nothing.--Voltaire (1694-1778)
Ills--Sjogrens-Lupus-like AI Disease, Hashis, Vitiligo, spinal stenosis/fusion with plate, salivary/lymphectomies, Diabetes, NAFLD, COPD, RLS, neuropathy, trigonitis, hystero, diffuse brain atrophy
Meds--Plaquenil, Evoxac, Metformin, Synthroid, HCTZ, Estradiol patch, Prosed, Klonopin, Soma, Ultram, Vicodin, Restasis, Albuterol,steroid injections, Protopic & Triamcinolone Acetonide ointments