Why do I feel itchy down there after sex?

Many years ago, talking about sex life was still a shameful thing, and people would not discuss this topic in public occasions. But now it’s different. Times are progressing, and sex life is beginning to enter the classroom in the right way. A harmonious married life is good for enhancing the relationship between husband and wife, but some female friends find that they feel itchy down there after having sex. What causes this?

Considering the possibility that it is caused by diseases such as vaginitis and vulvitis, it is necessary to check and then treat the symptoms.

Vaginitis, or inflammation of the vagina, is a group of conditions that cause vulvovaginal symptoms such as itching, burning, irritation, and abnormal discharge. The vagina of a normal healthy woman has a natural defense function against the invasion of pathogens due to the characteristics of its anatomical tissue. For example, the closure of the vaginal opening, the close contact of the anterior and posterior walls of the vagina, the proliferation of vaginal epithelial cells and the keratinization of surface cells under the influence of estrogen, and the balance of vaginal acidity and alkalinity inhibit the reproduction of alkaline-adapted pathogens. The cervical mucus is alkaline. When the natural defense function of the vagina is destroyed, pathogens can easily invade and cause vaginal inflammation.

Under normal circumstances, aerobic bacteria and anaerobic bacteria live in the vagina, forming normal vaginal flora. If the ecological balance between the vagina and the bacterial flora is disrupted for any reason, conditional pathogens may form. Common clinical conditions include: bacterial vaginosis (accounting for 22% to 50% of symptomatic women), candidal vaginitis (17% to 39%), Trichomonas vaginitis (4% to 35%), senile vaginitis, and vaginitis in young women.

Causes

1. Bacterial vaginosis

In a normal vagina, lactobacilli that produce hydrogen peroxide are dominant. Bacterial vaginosis is an endogenous mixed infection caused by a decrease in Lactobacillus and an increase in Gardnerella and anaerobic bacteria in the vagina.

2. Candidal vaginitis

(1) 80% to 90% of pathogens are Candida albicans, which grow easily in an acidic environment and are diphasic bacteria (yeast phase and hyphae phase).

(2) The patient's vaginal pH is 4.0-4.7, usually <4.5.

(3) Conditionally pathogenic bacteria (yeast phase → mycelium phase).

(4) Common causes: pregnancy, diabetes, and large-scale use of immunosuppressants and broad-spectrum antibiotics.

(5) Other contributing factors: gastrointestinal Candida, wearing tight synthetic underwear, and obesity.

3. Trichomonas vaginitis

(1) Trichomonas vaginalis grows best in a humid environment with a temperature of 25℃ to 40℃ and a pH of 5.2 to 6.6.

(2) The vaginal pH changes before and after menstruation, becoming close to neutral after menstruation, making it easier for Trichomonas to reproduce.

(3) The patient's vaginal pH is generally between 5.0 and 6.5, with most cases being > 6.0.

(4) Parasitic on the vagina, urethra or paraurethral glands, bladder, renal pelvis, male foreskin folds, urethra, and prostate.

(5) Often coexists with other vaginitis.

4. Senile vaginitis

Postmenopausal women have declining ovarian function, lower estrogen levels, vaginal wall atrophy, thinning mucosa, increased vaginal pH, reduced local resistance, and other pathogenic bacteria may over-multiply or easily invade and cause inflammation, mainly aerobic bacteria.

5. Vaginitis in young girls

It is caused by poor development of the vulva, low estrogen levels and foreign objects in the vagina of infants and young children, which trigger infection. Common pathogens include Escherichia coli, Staphylococcus aureus, Streptococcus aureus, etc.