Causes of Vaginal Itching
Sexually Transmitted Diseases
A condition called Trichomoniasis is caused by a microscopic, single-celled parasite and is spread through intercourse. Other STDs that cause inflammation and itching of the vagina include chlamydia, herpes, genital warts, and gonorrhea. Sexually transmitted parasites like lice, scabies, and crabs can also cause itchy vagina.

Vaginitis
Vaginitis simply refers to inflammation of the vagina. Women who suffer from vaginal itching before period time often suffer from this condition, as more blood flow rushes to the genital region during this time, causing tissues to become inflamed.

Allergies
Sometimes women are allergic to feminine hygiene products, douches, sprays, soaps, or spermicides, which may cause vaginal itching without discharge or even with discharge. This is not caused by any type of infection, but is simply the body’s reaction against a foreign substance it does not like.

Bacterial Vaginosis
BV is the most common cause of itchy vagina. The female vaginal naturally contain both "good" bacteria (lactobacilli) and "bad" bacteria (anaerobes). To keep a healthy balance, the good must outnumber the bad bacteria. When there is an overgrowth of anaerobes such as Gardnerella vaginalis, it disrupt the pH balance of the vaginal flora and bacterial vaginosis infection occurs. The risk increases with women who use IUD birth control, have multiple sex partners, or women who have just started relations with a new sex partner. Certain medications may also affect a woman’s ability to fight off bad bacteria.

Yeast Infection
Some women have genital itching after childbirth because their body’s hormones are imbalanced, which may trigger a fungal infection as the fungus Candida albaicans proliferates. Yeast infections can occur in women of any age, however. In fact, this same fungus causes diaper rash in babies. According to the Centers for Disease Control and Prevention, 3 out of 4 women will develop a yeast infection at some point in their lives. Risk factors include antibiotic or steroid use, uncontrolled diabetes, and hormonal changes associated with birth control pills, pregnancy, or menopause.

Atrophic Vaginitis
This condition occurs when vaginal tissues thin and dry out, usually after menopause, as estrogen levels diminish. Noninfectious vaginitis may be a reaction to soaps, spermicides, or perfumes.