What Are The Red Itchy Rash On Fingers,toes And Thighs?

I am recoverying from a throat infection but have just strted getting a red itchy rash on knuckles and toes, tops of feet, elbows, behind knees and once on thighs. There was one hive on my elbow but is mainly blotchy red and itchy. Could you advise me what it could be and what i should do? Thanks