itchy rat leason on tail and itching to point of bleeding

my rat keeps getting leasons on his tail along with being itchy all the time to the point of bleeding any suggestion? ive already changed the type of bedding

[ireneo]

Could be a fungal infection, could be skin mites but that would normally affect the whole body.

[ireneo]

Could be a fungal infection, could be skin mites but that would normally affect the whole body.