I Have Had An Itchy Scrotum For Going On 15

I have had an itchy scrotum for going on 15 months now.. diagnosed as 1: jock itch, 2: eczema.. Treatments have all proved futile some expensive. Today another dermatologist diagnosed it as red scrotum syndrome and prescribed Allegra 180mg orally. I have googled Allegra with Red ball syndrome online and can't find on single example of this treatment for my problem. Can you tell me if the Allegra will actually work? I desperate to find some relief from this constant burning and itch.