Weird swelling type things appearing on my arm?

..Hi Harley, This could be a couple of things..You may have ingested or eaten or drank something you may be allergic to, which can or will cause hives, and if this is the case watch your breathing and if this becomes difficult or in any way different than usual, then go to the hospital immediately...An allergic reaction can be very dangerous, so do not fool around if you think this may possibly be it at all..Recheck your steps to see if you have eaten/drank anything that you have not or haven't eaten in awhile, and especially if nuts are involved..Secondly, it could be bites of which you again may possibly be allergic to and/or have not yet built up an immunity against them..These can be from any number of insects we get, especially in the warm summer weather, including a type of house fly that does bite, and these types are smaller than the usual house fly..Again, watch your vitals and you will know if/when it is time to either call your doctor or go the hospital...Ice will help the swelling and alcohol rub will help with the itching..Remember too that most insects, especially mosquito's & spiders do come out in the night, usually when we are asleep, for their feeding...Do Take Care...