What Causes Itching In Vulva Area During A Menstrual Period?

Hello. Today I began to feel itchiness on my vuvla and when I took a look I noticed rash like little red bumps. I have been on my period and was thinking that it could be from wearing a pad and from sweating or decreased air flow down there. I went to sleep without underwears on and noticed that redness went away but the vuvla area is still itching. Could this simply be a skin issue?