First of all... There is difference between "other steroids" and the steroid prescribed for u... The other steroid, what we usually hear about is to increase body mass and function are not the same ones you r taking. Dont mix them up.
Nasonex is a local steroid which helps in reducing the inflammation (which is caused by the allergy). There is no "harm" as such in taking these steroids over a long period of time. Yes, there are side effects to all the medicines n so does your nasonex has. Ignore the internet findings and just go with ur dr.