some experience this because of yeast infection or a woman is in menopausal stage.

you`ll definitely experience some allergies, like you mentioned wearing tight undies or that is not suitable to your size.

I think you had some allergies in the skin of your vagina, and you can't wear tight jeans because it can cause much of your allergy.

some also experience it from using harsh soaps or fitting pants/shorts from departments stores.

harsh washing, yes it is especially when you douch it.

i have been feeling a burning sensation before and it's really itchy. the cause of it happened when i was into medication then.