A quick look at the story will help you treat/prevent that itch, and what could have caused it. Picture: Pexels
Whether you’ve been having sex with the same partner for years, or if it’s a one-night-stand, there are few things in the world that set off alarm bells as an itchy vagina after sex.

Sperm allergy: 

Thanos Papathanasiou, a fertility specialist and gynaecologist says If you've developed an allergy to your partner's sperm, your vagina may feel itchy after sex. A sperm allergy (also known as semen allergy or seminal plasma hypersensitivity) can also make your belly feel swollen or painful, with a burning sensation.

Inflamed vagina:

According experts, when your vagina and vulva are inflamed, it’s known as vulvovaginitis. In addition to a swollen vulva, vaginitis could lead to  unusual vaginal discharge and  itching.

Allergic reaction: 

Doctors don’t know why some people experience allergies. Allergies appear to run in families and can be inherited. If you have a close family member who has allergies, you’re at greater risk for developing allergies. An allergic reaction that causes your vulva to swell is known as noninfectious vaginitis. This can result from chemicals in:  clothing,  creams, lube and  condoms.

Over cleaning:
 
Douching and using heavily-fragranced soaps and body washes on your sensitive vulva region is a big no-no even when you want to clean up before sex. 

Yeast infection: 

According to Mayo Clinic, a vaginal yeast infection is a fungal infection that causes irritation, discharge and intense itchiness of the vagina and the vulva – the tissues at the vaginal opening.
Also called vaginal candidiasis, vaginal yeast infection affects up to 3 out of 4 women at some point in their lifetimes. Many women experience at least two episodes.

Here is how to treat/prevent it: 

How vaginal discomfort is treated depends on what condition is causing the problem. Here are some tips from WedMD to help you deal with the problem. 
  • Use water and a plain, unscented soap to regularly clean your external genital area. But don't wash more than once a day. Doing so can increase dryness.
  • Always wipe from front to back after having a bowel movement.
  • Wear cotton panties (no synthetic fabrics), and change your underwear every day.
  • Use condoms during sexual intercourse to help prevent sexually transmitted diseases.