Suggest Medication For Redness And Itchiness In Vaginal Area Due To Tampon Usage

I went swimming in the ocean a few days ago with a tampon in. Once I came back on shore I took the tampon out since it was soaking in more saltwater than anything. Once fully done swimming I changed out of my bathing suit. It s been three days and my vaginal area is red and itchy without discharge or smell. What could it be and how can I treat it?