What Causes Brown Spots On My Legs That Are Rough To Touch?

Hi doctor. I've had a sort of brown spots on my legs since I ever could remember. They are rough to the touch, brown, pimple like and they go from my legs to thighs. The spots are not due to shaving because i dont use a razor or anything abrasive and I have a history of allergy. I have tried stopping hair removal, exfoliation but none have worked so far apart from fade them a bit, but never remove them. Could you please tell me if there is any possible solution? Thank you.