The anatomical and physiological characteristics of the vulva and vagina form a natural defense function: (1) the labia majora on both sides naturally close together to cover the vaginal opening and urethral opening; (2) the vaginal opening is closed due to the action of the pelvic floor muscles, and the front and back walls of the vagina are close together to prevent external pollution. The vaginal epithelium is thickened under the influence of estrogen secreted by ovaries, which increases the resistance to pathogens, and the epithelial cells are rich in glycogen, which decomposes into lactic acid under the action of Lactobacillus and maintains the normal acidic environment of the vagina (pH ≤ 4.5, mostly 3.8-4.4), so that pathogens adapted to breeding in a weak alkaline environment are inhibited. Pathogens adapted to reproduce in a weak alkaline environment are inhibited. Under normal conditions, aerobic and anaerobic bacteria reside in the vagina, forming a normal vaginal flora. Aerobic bacteria include: Corynebacterium, non-hemolytic streptococci, enterococci, and Staphylococcus epidermidis. The parthenogenic anaerobes are Lactobacillus, Gardnerella and Escherichia coli. Anaerobic bacteria include digestive cocci, digestive streptococci, bacillus-like bacteria, clostridium and actinomycetes. There are also Mycoplasma and Candida. The vagina forms a balanced ecology with these flora, the vaginal environment influences the flora and the flora influences the vaginal environment. Lactobacillus predominates in the normal vagina and plays a key role in maintaining the normal vaginal flora. Although there are defense mechanisms in the vulva and vagina, the vulva is vulnerable to contamination because it is adjacent to the urethra in the front and to the anus in the back; the vulva and vagina are also essential for sexual intercourse, childbirth and various uterine operations and are susceptible to damage and infection by various external pathogens. In addition, although the vaginal flora is normal, the ecological balance between the vagina and the flora can be disrupted when a large number of antibiotics are applied, hormonal changes occur in the body or the immunity of the body is reduced for various reasons, and conditional pathogenic bacteria can be formed. The common features of vulvovaginal and vaginal inflammation are increased vaginal discharge and vulvar itch, but the characteristics and nature of the discharge and the severity of the itch vary depending on the cause of the inflammation. Trichomonas vaginalis [Etiology] is a common vaginitis caused by Trichomonas vaginalis. The temperature suitable for trichomonas growth is 25℃～40℃ and pH is 5.2～6.6 in a humid environment. It does not grow in environments with pH below 5.0 or above 7.5. The vaginal pH of trichomonas vaginalis patients is usually 5-6.6, mostly >6.0. The vaginal pH changes before and after menstruation and approaches neutrality after menstruation, so the trichomonas hidden in the glands and vaginal folds often multiply before and after menstruation, causing inflammatory episodes. It consumes or engulfs glycogen in vaginal epithelial cells and prevents lactic acid production. Trichomonas is not only parasitic in the vagina, but also in the urethra or paraurethral glands, and even in the bladder and renal pelvis, as well as in the male partner’s foreskin folds, urethra or prostate. The way of infection is: ① direct transmission through sexual intercourse; ② indirect transmission through public baths, bath tubs, bath towels, swimming pools, bidets, clothing, etc.; ③ medical transmission: transmission through contaminated instruments and dressings. Clinical manifestations] The incubation period is 4 to 28 days. The main symptoms of trichomonas vaginalis are increased thin foamy leucorrhea and itchy vulva, if there is a mixture of other bacteria, the discharge is purulent and may have an odor. Itching is mainly at the vaginal opening and vulva, with occasional burning, pain, and painful intercourse. Trichomonas vaginalis can swallow sperm and prevent lactic acid production, which can affect the survival of sperm in the vagina and cause infertility. If there is infection in the urethra, there may be frequent and painful urination, and sometimes hematuria is seen. On examination, the vaginal mucosa is congested, and in severe cases there are scattered bleeding spots. The posterior curvilinear ronge has a large amount of leucorrhea, which is a thin grayish yellow, yellowish white liquid or yellowish green purulent discharge, often frothy. The vaginal mucosa often has no abnormal changes in those with worms. Diagnosis】Typical cases are easily diagnosed if trichomonas is found in vaginal secretions. The easiest way to check for trichomonas is the suspension method. In symptomatic patients, the positive rate can be 80-90%. To do this, add a small drop of warm saline to a slide, take a small amount of discharge from the back of the vagina, mix it with the saline and immediately look for trichomonads under a low magnification light microscope. If trichomonas is present, it can be seen to move in a wave-like motion and the surrounding leukocytes can be seen to be pushed. In suspicious patients, if trichomonas is not found by repeated suspension, it can be sent for culture with an accuracy of about 98%. Avoid sexual intercourse, vaginal irrigation or local medication for 24-48 hours before taking out the secretions, and do not make double examination before taking out the secretions. After taking out the secretion, send it for examination and pay attention to keep it warm, otherwise the activity of trichomonas will be weakened, which will make identification difficult. Prevention】Make good health propaganda, actively carry out census and universal treatment to eliminate the source of infection. Strict management system, trichomonas patients or those with worms should be prohibited from entering the swimming pool. Bath tubs, bath towels and other utensils should be disinfected. Medical units must make good disinfection and isolation to prevent cross-infection. Treatment】 1, systemic medication metronidazole 400mg, 2-3 times a day, 7 days as a course of treatment; for the first time patients a single oral metronidazole 2g, can receive the same effect. Oral absorption is good, high efficacy, low toxicity, and easy to apply. Sexual partners should be treated at the same time. Gastrointestinal reactions, such as loss of appetite, nausea, vomiting, are occasionally seen after taking the drug. In addition, headache, rash and leukopenia are occasionally seen and should be discontinued once detected. Metronidazole can be excreted through breast milk, so if the drug is used during breastfeeding, it is better not to breastfeed during and within 24 hours after the drug is administered. 2.Local medication can be administered locally alone or in combination with systemic and local medication, but the combined effect is better. Metronidazole tablets 200mg should be inserted into the vagina once a night, 10 times as a course of treatment. Before topical administration, the vagina can be rinsed with 1% lactic acid solution or 0.1-0.5 acetic acid solution to improve the vaginal environment to improve the efficacy. Trichomonas vaginitis often recurs after menstruation, so if the test is negative for trichomonas after treatment, the leucorrhoea should be rechecked after each menstruation, and if the test is negative for 3 times, it will be called cured. 4.Cautions in treatment When the trichomonas test is negative after treatment, you should continue the treatment for one course after the next menstruation, in the same way as before, in order to consolidate the efficacy. In addition, to avoid repeated infections, underwear and towels should be boiled for 5-10 minutes to eliminate pathogens; married people should also check whether the male partner has genital trichomoniasis and whether the prostate fluid has trichomonas, if it is positive, it should be treated at the same time. Candida vaginitis [Etiology] Candida vaginitis is a common vaginitis, misnamed mycotic vaginitis in the past. 80 to 90% of the pathogens are Candida albicans, which is a fungus. Candida is not very resistant to heat and can die when heated to 60°C for 1 hour; however, it is more resistant to dryness, sunlight, ultraviolet light and chemical agents. Candida albicans is a conditionally pathogenic organism, which is found in the vagina of about 10% of non-pregnant women and 30% of pregnant women and does not cause symptoms. The pH of the vagina with Candida infection is between 4.0 and 4.7.