Talk to Gynecologist on Skin Problem At Vaginal Area

My daughter has developed a skin problem having red skin with white pimples along vagina and anal skin. The lips of vagina , the sides of legs and skin around anus is affected. It's been a month. If it's diaper rash then it should have improved when I removed diaper and just used at night. Peds cream, rationil, fusil , hydrozol creams I HV tried but of no avail. Sometimes I see a whitish discharge too. PS: it started when she had some stomach disturbance. But she is not having any big problem. This rash is not going away in any way .