Use a comma to separate nonessential elements from a sentence. More specifically, when a sentence includes information that is not crucial to the message or intent of the sentence, enclose it in or separate it by commas.
Genital warts are a sexually transmitted infection (STI) caused by certain strains of the human papillomavirus (HPV). These skin growths can cause pain, discomfort, and itching. They are especially dangerous for women because some types of HPV can also cause cancer of the cervix and vulva.
Causes of Verruca Plana. They are common growths caused by an infection of the surface (superficial) skin with the human papillomavirus (HPV), which thickens the top skin layer. Warts may spread in humans by person-to-person contact or, rarely, by touching an object used by an infected person.