It totally could be hives OR an allergic reaction. Have you started to eat/drink something else than usually? Or maybe you took some new vitamins/drugs or something? Some plants, animals, chemicals could cause it too. Maybe the doctor no.2 suggested some kind of treatment?
The 4th one says-rule out 'Scabies'.Any friends or contacts with itching?
sounds lke fleas f mosquio bites both itch alot also there could be bed bugs
try sleeping over a friend house if your still have the same thing i will not know