Hi Barbara,
I had something similar that turned out to be folliculitis. Looked just like those images you’ve posted and I experienced similar phenomena. They were localized. Mine were on my outer arms and shoulders, and then on my calf not far from a gigantic surgery scar. Sometimes they were very inflamed– like if I was having a histamine reaction to food or if I picked at them. I noticed they were sensitive to the sun, but I knew they weren’t caused by the sun. They healed very slowly. After many years and tons of scarring, I finally had a biopsy that confirmed folliculitis. While I’m certain histamine played a role, in keeping them inflamed and active, a loooong round of antibiotics cleared it up almost entirely where no previous interventions had done anything to help at all. I highly recommend you go to a dermatologist who will likely take a biopsy which will help you to know what they are, or at least what they aren’t. Skin problems are tricky to dx.