Jock itch, known in medical terminology as tinea cruris, is a superficial fungal infection of the groin skin. The infection occurs most commonly in adult and adolescent males but may also affect women. Jock itch appears as distinct patches of reddened, itchy skin in the groin, inner thigh and anal area. The causes of jock itch include habits and behaviors that favor the growth and spread of the offending fungi.
Damp Underclothing
Warm, damp conditions favor the growth of the fungi that cause jock itch. Wearing a perspiration-soaked undergarment or athletic supporter for a prolonged period may trigger the development of jock itch, reports the medical information website InteliHealth. Changing out of wet clothing at the conclusion of an athletic event or workout may help decrease the risk for jock itch.
Tight Underclothing or Pants
Tight underclothing and pants trap heat and cause skin friction, which may favor the growth of jock itch fungi. Loose-fitting clothing helps keep the groin skin dry and avoids skin abrasion.
Unlaundered Undergarments or Pants
The fungi that cause jock itch may contaminate undergarments or pants. Wearing these items without laundering between uses may provoke a case of jock itch, notes University Hospital of the University of Southern California. Laundering and thoroughly drying clothing items, especially athletic wear, between uses may decrease the likelihood of developing jock itch.
Sharing Contaminated Towels or Clothing
The fungi that cause jock itch can live on inanimate objects, such as towels. Sharing a towel with a person who has a fungal skin infection without laundering between uses may lead to the development of jock itch, reports the InteliHealth website. Sharing unlaundered clothing, especially undergarments and bathing suits, can also lead to tinea cruris.
Self-Inoculation
The medical information website Doctor Fungus reports that people with a fungal infection of the feet, or athlete's foot, can spread the infection to the groin, leading to jock itch. The fungus may spread on a towel or via contamination of the hands. Patients who have athlete's foot can reduce the risk of spreading the infection to other parts of the body by using separate towels for the feet and body, and washing the hands with soap and water after touching the feet.
Infrequent Bathing
Infrequent bathing or showering can lead to an overgrowth of fungus on the skin, potentially leading to the development of jock itch. Regular showering or bathing---especially during warm weather or after participating in activities that cause profuse sweating---may help reduce the risk of developing jock itch.
Sexual Contact
Tinea cruris can spread from one person to another during sexual contact, reports MayoClinic.com. Topical antifungal treatment for jock itch generally clears the infection within two weeks, according to the National Library of Medicine encyclopedia MedlinePlus.
