Hello dear Understand your concern I think this spot is due to previous infections. Other causes are: poor hygiene problem, allergic reaction, fungal infection, benign malinosis (require to evaluate by excision if spot persists after rule outing all other cause). For Exact diagnosis need to consult the gynecologist and get the done following investigations: KOH mount preperation, vaginal swab test to rule out infection, gram stain, cell culture, STD screenings. Mean while take following advice: Single dose treatment : Azithromycine + tinidazole + flucanazole, Use simple unperfumed soap, avoid douching, Avoid colored or perfumed toilet tissue and bubble bath, Take shower after work out and change the undergarments as early as possible, wipe pelvic area after urination, sex and bowel movement, lactobacilli vaginally, avoid excessive sugars in diet, wear pure cotton loose undergarments, Avoid overexertion and scratching. Hope this may help you Best Regards. Dr. Sagar