What pigiron posted is absolutely CORRECT and what I have found to help more than anything,since the itch is an allergic reaction ,is to put anantihistamine stop itch cream,(I like the benadryl gel) and take a couple Benadryl tabs and that seems to work better than any home remedy I have tried.

I believe that covering the spots with fingernail polish does help,just because it cover the spot and prevents the area from being irritated as bad but the above does a much better job stopping the misory imo.