There is no medical term for mycosis fungoides, it should be mycosis vaginalis. It is medically called vulvovaginal pseudomycosis. It is a common vulvovaginal inflammatory disease in women caused by Pseudomonas. Mycosis vaginalis is an opportunistic infection. Normally, 10%-15% of non-pregnant women and 30% of pregnant women have Pseudomonas albicans parasitized in their vagina, but the number is very small and does not cause an inflammatory reaction. If patients use broad-spectrum antibiotics for a long time, use a lot of immunosuppressants or receive a lot of estrogen therapy; pregnancy; diabetes; fecal contamination of the vagina by gastrointestinal Pseudomonas infections; wearing tight-fitting chemical fiber underwear and obesity to increase the local temperature and humidity of the vulva, etc., all of them can make the whole body or the local resistance of the vagina decrease, resulting in the proliferation of Pseudomonas and causing mycosis fungoides. Pseudomycetes can be parasitized in the vagina of women and in the folds of the foreskin of men, so mycosis can be transmitted directly through unprotected contact. It can also live in the mouth and intestinal tract, and these parts of Pseudomycetes can be transmitted to each other. For example, if the anus is wiped from back to front after a bowel movement, the white pseudomycetes in the gastrointestinal tract contaminate the vagina and cause mycotic vaginitis. A small number of patients are infected indirectly through contact with infected clothing. Therefore, mycosis vaginitis is easily triggered when patients have poor body resistance, frequent unprotected sex or contact with feces and clothes contaminated by Pseudomonas. It is recommended to pay attention to personal and sexual hygiene; keep the vulva clean and dry; change and disinfect close clothing regularly; and actively treat diabetes.