Itchy, contagious and in a place you'd rather not mention, jock itch (tinea cruris) is a fungal skin infection that affects the genital region.
While many people refer to jock itch and other forms of tinea as "ringworm," this infection has nothing to do with worms. However, it has everything to do with several persistent species of fungi known as dermatophytes.
These dermatophytes cause a pink, scaly rash to form on the inner thighs, groin and scrotum of their male victims. And although it's normally associated with men, jock itch can also affect women, causing the same itchy, scaly rash to form on the vulva.
All forms of tinea are fairly contagious and can spread from person to person, as well as through contact with surfaces that harbor fungi, like shower floors and damp soil. And because the dermatophytes that cause jock itch are the very same ones that cause athlete's foot, the fungi often spread from foot to genitals by wet towels or damp clothing.
Although the fungi that cause jock itch are persistent, they're also fairly easy to kill. Topical anti-fungal medications often effectively treat most forms of tinea. However, because many people who acquire fungal infections like athlete's foot and jock itch continue engaging in the activities that resulted in their exposure to the infection (such as using communal showers, pools or spas), reinfection with dermatophytes is common.
To avoid fungal infections, wear water shoes or sandals in communal spaces such as locker rooms and pool decks, and avoid using the same towel to dry feet and groin areas. Wash towels and clothes stored in a locker frequently, as fungi can flourish under these damp, dark conditions.