May be suffering from mild vaginal infection .Follow the below advice , u will get relief
http://womenscure.com/suffering-from-vulval-itch/
Next Steps
Internal per vaginal examination gives few details
Health Tips
Wash your genetelia with excess water , don't use tight pants and panties , use cotton wear .Expose your genetelia to air , when you are alone in room . Don't use deodorants ,douches to ur private parts . Use hygienic methods for pubic hair removal