May I ask if are there any concomitant vaginal discharge or bowel symptoms? The complaint of just isolated itch alone is a little unusual, especially if there are no skin changes.
In essence you would need it to be looked at by a doctor, and two main conditions excluded – either pinworms or lichen sclerosus.
If both are ruled out by the doctor, then you might want to consider perhaps a short course of topical corticosteroids eg mometasone cream.
