2yrs ago i started having daily allergic reactions. (face mouth tongue swelling). i take claritin & zantac (ranitidine) daily.they can not find a cause. thoughts?

Not unusual: When urticaria and angioedema are continuous for more than 6 weeks there is often no obvious cause. It is considered "idiopathic". The main object is to find a combination of medication to control the symptoms without having to use oral steroids like prednisone. Make sure you are not taking an "ace" medication which can predispose to this type of problem. It may be time to see an allergist.

Angioedema causes: I assume you have been evaluated by an allergist. Your condition, called angioedema, can be secondary to medications, or acquired from an underlying disease, or hereditary if you have members of the family with same symptoms, or idiopathic, which is an unknown cause. If you did not see an allergist, i would recommend seeing one.