Jock itch is a fungal infection in the groin area. Dermatophytes, the fungal group that causes jock itch, can infect other areas of the body as well. They can infect the scalp and beard area, causing bald patches. On the feet, the fungi can cause athlete's foot, while on the body it causes ringworm. Cross-contamination between infected areas is common.
Rash
Dermatophytes prefer moist, dark, warm areas. They enter the body through breaks in the skin and spread throughout the layer of dead skin cells that make up the uppermost layer of skin, called the stratum corneum. The dead cells are keratinized, meaning they have large amounts of the protein, keratin, which the fungus metabolizes. Skin responds to the infection by producing an allergic response. The response includes a rash. The jock itch rash generally appears in creased areas of the groin area, including the upper, inner thighs and between the buttocks. It affects more men than women, and, in men, jock itch infection usually does not affect the scrotum or the penis. Medline Plus,a publication of the National Institutes of Health, points out, however, that the infection can spread to the anus.
Scaling
Unlike green plants that convert sunlight into energy, fungi do not need light. They live off of a host. In order to metabolize keratin, the fungus excretes an enzyme that breaks the keratin down. This process causes scaling of the skin, as well as breaks in nails and hair, which also have high keratin contents. The jock itch rash usually has a defined outer edge with crusted, scaling skin.
Other Indications
The Cleveland Clinic reports that a jock itch infection often includes itching and burning. Blistering in the groin area may also be an indicator of the infection. Secondary bacterial infections can occur in dermatophyte infections as skin is already compromised. Over the long term, if left untreated, permanent skin discoloration may occur as a result of a jock itch outbreak.
