What Causes Itching And Redness In Vulva?

Hi there. I've recently developed a really bad itch 'down there' around my vulva. I've had it for a few days now. I'm not getting any vaginal discharge, and it's not an STI because I've had unprotected sex with my husband for over 6 months and we're both free from any STIs. My only symptoms is this itching and some redness of my vulva. I think I have a rash too, but not sure.