Tiny Little Red Itchy Bumps On Arms, Chest And Neck. What Could It Be ?

hello. for the past 2 weeks I have had these tiny little red bumps and every now and then they itch. but other times during the day they don't. currently, they are on a small portion of my right arm and my left, a little on my chest, and two small spots on my neck. thing is, they itch more when I sweat. im active in the summer so they somewhat itch. right now though they don't. and at times, I have no itch whatsoever...what is it? I tried anti itch stuff that I put on. that somewhat helped, and I had benedryl thinking it was an allergic reaction.