From your description, I assume that your daughter has a labial adhesion, a thin membrane that covers all or part of the vaginal opening. This is a common disorder in young girls between the ages of three months and six years. It rarely causes any symptoms. Labial adhesions stem from irritation, poor hygiene, and bacterial infection. Most of them disappear spontaneously within a year.
I discussed your concern about using Premarin with Sandy Newmark, M.D., a California-based integrative pediatrician who is on the faculty of the Arizona Center for Integrative Medicine. Dr. Newmark said that unless the adhesion covers the entire vaginal opening preventing urine and vaginal secretions from escaping, it is totally harmless and probably will resolve on its own. He said that no treatment is necessary and cautioned that parents should not try to force an adhesion open manually.
When treatment is needed, Premarin cream usually is recommended (although Dr. Newmark emphasized that it doesn't appear necessary in this case). When prescribed, the cream is applied twice a day for two to eight weeks until the adhesion begins to separate. Side effects are rare but can include local irritation, a change in pigmentation of the vulva (the external female genitalia) and breast enlargement, all of which disappear once treatment stops. After the adhesion separates, a diaper rash cream or antibiotic ointment probably will be recommended to help the area heal. Because irritation may be a factor in the formation of labial adhesions, avoid washing the area with harsh or scented soaps.
Andrew Weil, M.D.