I had teporal artiritis since 3 1/2 yrs ago and have been on predisone all of thei time .Now am taking 2 pill a day. Recently had a rash develop on my body. Boipsy determined it to be an allergen. Visited a dermotologist and now an allergy doctor. He said to take one allegra aday. Third day I developed severe pain in my right leg. I stopped the Allegra. Is there a relationship to these drugs?