Hi
Hi, Form your long history it seems there is nothing special found in her tests and all medicines tried. Now there is one possibility of having Worm infestation where worms come out of anal canal and migrates in front to lower genital tract to vagina, clitoris might produce itching on this area. Go for stool test for ova, cyst and worms. Even empirically you can give her one course of anti-worm medicine like Albendazole. Keep her local hygiene clean and airy. Ok and take care.