Felt compelled to reply... I stumbled to this site looking for new info on BRP (=bracchioradial pruiritis)... as it is making me go mad, mad, mad! I can totally relate to "cry, scream, meltdowns" too. It is so maddening!! For those looking for temporary relief, my go tos, here in Canada, are: Xylocaine 5% (which I think may be Lidocaine in US)... this numbs your arms (but takes an hour to take effect, i find) and Stopain!, which is a strong menthol-type roll-on cream that feels super cold... so cold that it hurts a little (but at least you don't feel itchy). Hope this helps someone.
As for next steps, for me, I'm booking an appointment at chiropractor. Hopefully he'll take xrays and see something? Or perhaps an "alignment" of my spine will help? I'm desperate! Keep looking for answers people!!