Hello I Have Been Itchy For The Past Three Months

hello i have been itchy for the past three months and I have tried everything even the doctor has too by doing things such as taking blood samples and doing allergy tests nothing has shown up so far, tried every kind of cream and anti histamine again nothing has worked it is driving me crazy as I cant sleep or concentrate my mum contacted a neurologist and he has said that it could be signs of a dirty liver. the rashes appear like little skin coloured spots an are extremely itchy, also I would like to add that I have changed everything such as shampoo bedding shower also washing powders any one know what this might be thank you in advance as this is driving me INSANEEEEEE!!!!!!!!!!!!!!!!!! :)