What Causes Red Spots On The Palms Of My Hand And Fingertips?

i am 19 years old and i have had these red spots on the palms of my hand and fingertips. i have had them a little over a month now and they come and go as they please. usually only lasting about 2 to 3 min. i never had them before and when i went to my local doctor he said they were a form of hives and gave me a steroid pack to take for a week and they still came back. everyone keeps telling me im allergic to something but i have nka. nothing in my daily routine has changed and im not sure what to do. the spots itch only a tiny bit and they always hurt when they start to show up.