Red Swollen Itchy Mark On The Foot, Elbow, Knees Not Disappearing By Anti Itch Creams. Is It An Insect Bite /allergic Reaction?

Today at school, I felt a severe itch on my foot which lasted for most of the day. When I finally got home, I removed my shoes and socks and there on my right foot was a red, swollen, itchy mark. I applied some anti-itch cream, but it did not seem to help. Then, just minutes later, this same mark appeared upon my left elbow and an hour or so later on my right knee. I think it is some sort of insect bite, but I've been wearing jeans and a hoodie all day and the anti-itch cream usually soothes them. Another possibility that was suggested by family member, it could be an allergic reaction to something, but I do not know what. Thank you for your time.