The moist, slightly acidic environment of a normal, healthy vagina supports a population of bacteria, protozoa and yeast living together in balance. Factors such as exposure to allergens, harsh chemicals, or infectious agents can alter the normal balance of the vagina, and vaginal itch can be the first sign that something has gone awry.
Allergy
The lining of the vagina (vaginal mucosa) can suffer from contact allergies like any other tissue. Vaginal and labial itching can result from a contact allergy. Women who are allergic to latex can suffer intense vaginal itching after intercourse with a partner using a latex condom. To prevent the allergic reaction, but still provide protection from sexually transmitted diseases, a partner could wear a latex condom covered by a natural skin condom. Other common culprits include feminine sprays and harsh or scented soaps and detergents.
Irritation
The vaginal mucosa normally stays moist and at a slightly acidic pH. Factors that alter the pH or dry the mucosa can irritate the vagina, making it itch. Again, feminine sprays and harsh or scented soaps and detergents can have this effect. Douching too often can also irritate the vagina and make it itch. To keep the vagina clean and healthy, regular bathing with mild soap and water is sufficient. Long sessions in a spa, hot tub or bubble bath dry out the vagina and alter its balance of natural organisms, making it itch.
Yeast Infection
A yeast infection, medically known as candidiasis, is caused by the fungus Candida albicans. According to "Primary Care for Women," up to 75 percent of women experience a yeast infection during their lifetimes. The major complaint of women with a yeast infection is intense vaginal itching, although the infection can cause a smelly, thick white discharge as well.
Infectious Vaginitis
In addition to a yeast infection, other forms of infectious vaginitis can cause vaginal itching. Bacterial vaginosis, usually sexually transmitted, results from an over-population of anaerobic (non-oxygen using) bacteria that kill off the normal aerobic vaginal bacteria. In addition to itching, women with bacterial vaginosis have increased vaginal discharge with a characteristic fishy odor that gets worse after anything that increases the pH of the vagina, such as semen or menstrual blood. According to "Primary Care for Women," overgrowth of the protozoan Trichomonas vaginalis, or trichomoniasis infection, usually sexually transmitted, causes vaginal itching along with painful urination and a foul-smelling, copious and frothy greenish-yellow vaginal discharge.
References
- Mayo Clinic.com: Vaginitis
- "Primary Care for Women"; Phyllis Leppert and Jeffrey Peipert; 2004
