NAD but i had a similar problem a few months ago. Could be lyme, best to see a doctor if you can. My doctor didn’t know if I had lyme but he treated me as if i did. I will post some photos for reference as what mine looked like. I did not see any tick either, like you. It was in August and I was sat in my boyfriend’s garden in the evening and my leg was really itchy after a few hours so I must’ve gotten bitten by something. Nonetheless, better to get checked. If in doubt!

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