Appearance and size of warts depend on the location and the amount of irritation and trauma. Common warts are sharply demarcated, rough-surfaced, round or irregular in shape, firm, and either light gray, yellow, brown, or gray-black in color. They are small nodules ranging in size from 2–10 mm in diameter. Plantar warts (on the bottoms of the feet) are flattened and may be exquisitely tender. Flat warts, more common in children and young adults, are smooth, flat-topped yellow-brown elevations, most often seen on the face and along scratch marks. Genital warts (also called condyloma acuminata or venereal warts) are soft, moist, small pink or gray polyps that enlarge and are usually found in clusters on the anus and the warmer, moister areas of the female and male genitalia. Genital warts caused by HPV are considered a major cause of cervical dysplasia and cervical cancer. All warts are contagious.