Mycospores as an opportunistic pathogen are not caused by anything but a small amount of parasitism in the vagina of women or in the oral cavity or intestines of people. About 10-20% of non-pregnant women and 30% of pregnant women may have Pseudomonas aeruginosa, or mycobacterial parasites, adhering to the vagina, but the amount of bacteria is very small, mostly in the yeast phase, which is also known as mycobacterial spores and does not cause an inflammatory reaction. Mycobacterial spores play a role in asymptomatic residence or transmission, and when the host’s systemic as well as local cellular immunity of the vagina decreases, the mycobacterial spores will convert to the mycelial phase, multiply, grow and invade the tissue, thus causing an inflammatory response. The most common triggers for the development of mycosis vaginalis are the long-term use of broad-spectrum antibiotics, pregnancy, diabetes mellitus, heavy application of immunosuppressive agents, and receiving large amounts of estrogen therapy. Fecal contamination of the vagina by Pseudomonas gastrointestinalis infection can cause mycosis fungoides, and wearing tight fitting chemical fiber underwear and obesity, which increases the local temperature and humidity of the vulva, are also influential factors in the development of the disease.