How To Cure Itchy Red Rashes All Over The Body ?

Hi ...I am suffering from itching all over my body..for the past 1 week I am suffering from it....especially on my stomach,underarms and chest part..red ashes are appearing on these places...its really irritating and unable to concentrate on my work..please suggest me what might be the problem and the precautions I have to take...today I started using alerid,wysolone tablets..2 per day...are these tablets ok??