Hi and welcome to Healthcaremagic. Thank you for your query. I understand your concerns and I will try to help you as much as I can. In some cases purple areas may be normal and doesn’t need to indicate specific disease. However it his spreads, I would keep a possibility of Lichen planus, particularly annular variety of Lichen Planus, which is common on the genitalis. I would suggest that you seek an appointment with a dermatologist for a confirmatory diagnosis. Diagnosis is clinical. Treatment of Lichen Planus is commonly with topical steroids like mometasonepropionate, twice daily for a few weeks. Sometimes oral steroids may be required for widespread or diffuse disease. A OTC antihistamine e.g cetrizine once daily would help you symptomatically with the itch. I hope I have answered you query. If you have any further questions you can contact us in every time. Kindly regards. Wish you a good health.