What Causes Red And Painful Spots On Upper Right Chest And Shoulder?

I have red painful spots on my upper right chest/shoulder area that started appearing last night and a new spot appears every now and then throughout today. It looks like an allergic reaction to something, but it doesn t itch, it hurts to the touch. The red spots are about the size of mosquito bites or chicken pox spots but I have had chicken pox already and they aren t itchy. I am a 24 year old female.