So i have an itchy bumpy rash on my and need help....?

So its on my and back of my uppper thighs. Ive had it for several weeks i havnt used new detergent or anything. The bumps start small but slowly get bigger they arent red unless i scratch them. No puss or white head on them and its not acne either. Theyre hard bumps that dont hurt but are super itchy. Calamine lotion helps the itch for a bit but not long, sometimes the bigger bumps flake off the top when scratched but the bump stays. What the heck is this?