Last Sunday behind my ear was itching so i scratched a little then it began to itch more throughout the day and i kept scratching by Monday Morning my ear was swollen, warm to the touch and red. I had an o.b. appt on Monday, so I asked what he thought it was. He said cellulitis so he prescribed cephalexin 4 times a day. Today, i had a wallet with the handle that you can put on your wrist it made it itch and then again it started itching some more. I took the wallets off the wrist and tried to avoid scratching and in the process my wrist began swelling and it is warm to the touch and inflamed. Again something touched my hand and after scratching once or twice it started to swell up, so before it got as big as my wrist. I stopped scratching although it is still itching. Why has my skin become so sensitive or is this a reaction to the cephalexin.