Hello dear I understand your concern Dark patches could be due to fungal infection, contact dermatitis, dark discoloration, wart. Vaginal examination by the gynecologist is must to confirm the cause. Skin biopsy can be useful but after the clinical examination. Doctor will give following advises: For fungal infection Single dose of fluconazole Apply candid cream Apply benadryl cream Wash the area with warm salted water Wear pure cotton loose inner and avoid sweat, change it after work out, use simple and unperfumed soap and cosmetics Other treatment will depend on the specific cause Hope this may help you Contact HCM for further health query Best regards Dr. Sagar