Hi I Have Been Getting The Trangest Itchy Patches Which

hi I have been getting the trangest itchy patches which initially look like something small has bitten you these first appeared on my legs then all of a sudden within a few hours they become horrifically itchey with a brning sensation the area around the spots becom very inflamed then when they subside the actuall area about the size a twenty pences coin goes a violet red and gradually changes to a faded brown. Having been to the doctor he and I have ponered an alergic reaction to one of my meds . I have been diagnosed with AF and I am an accute diabetic tye 2 with diabetes and a long term medical problems. Lying in bed I wondered if this could be a connection to hives. They have now appeared on my mid body