At the beginning of the summer of 2012 I went on a 12 day kayaking trip in Glacier Bay Alaska. My instructor on the trip would get painful and itchy red bumps on the tops of his fingers. He said he never got them while kayaking anywhere else and they always went away a few weeks after the trip ended. He has talked to many people but has not been able to figure out what it is. I also got them on the trip, and while they did go away afterwards they have made several reappearance s. I can t link it to the cold as I just got them here in Florida. It might be associated with water, but I have gotten them even when I have been keeping relatively dry. The symptom begins as a painful slightly swollen red dot, a bit like a pimple . Its doesn t necessarily form a head with pus though it might. Eventually it dries out and leaves a slightly discolored scar which eventually fades.