Monday, my son was getting ready for school.  He sat down to tie his shoes, then almost immediately he said his fingers were really itchy and swelling.  I looked at them and they actually were.  I told him to go wash his hands and I put some hydrocortisone cream on them.   He often gets mysterious hives and it is very rarely something that progresses.  After this incident, he did not want to go to school.  I forced him to go to school because I didn't think anything was wrong.  The day went fine for him so I thought it was just a random hive incident.  Then yesterday we were out playing wiffleball in the street and he said his arms were itchy.  I told him to go put them in the snow b/c it was a rare occurrence that it was a warm day but still we had piles of snow around.  Immediately after he put his arms in the snow he started with hives covering his arms.   After some detective work, it looks like some areas are now using what is called cheese brine to melt the ice and snow on roadways.  I have to see if our township is doing this, which would explain his hives yesterday and Monday.  Check out this article.http://www.npr.org/blogs/thetwo-way/2014/01/21/264562529/cheese-to-the-rescue-surprising-spray-melts-road-ice