Jock itch, also known as shingles, is a fungal infection of the skin in the groin. A warm and humid environment is an ideal place for fungi to grow.
Anything that improves this environment puts the person at risk of itching. Therefore, wearing sweaty and damp clothing in summer or multiple layers of clothing in winter increases the incidence of itching in athletes. Men are affected more often than women.
The fungus that most often causes itching in athletes is called Trichophyton rubrum. It also causes fungal infections of the toes and the body.
Under the microscope, this fungus appears as translucent, branched, rod-shaped filaments or hyphae (tube-like structure). The hyphae are the same width throughout their length, which helps distinguish them from the hair, which tapers towards the end. Some hyphae have bubbles on the walls, which also distinguishes them from hair. In most cases, these fungi live only on the dead cells of the epidermis (the outermost layer of the skin).
Signs and symptoms
An itchy rash begins in the crease of the groin, usually on both sides. If the rash increases in size, it usually spreads over the inner thigh. The anterior margin is redder and higher than areas that have been infected the longest. The anterior margin is usually scaly and very easily distinguishable or well defined. The skin within the rim turns reddish brown and loses most of its scales.
Athlete's itch caused by the fungus T. rubrum mentioned above does not affect the scrotum or penis. If these areas are affected, you can most likely blame Candida albicans , the same type of yeast that causes vaginal yeast infections .
There are other rashes in the groin that can cause itchy-like symptoms in athletes. The first is called diaper rash , a macerated red rash in the groin that is not caused by a fungus. It is often seen in obese patients and occurs when wet skin rubs against other wet skin. The skin cracks and forms folds called fissures, which can be very painful. These cracks can become re-infected with fungi or bacteria. The edge of the eruption generally does not increase until much later in the life of the eruption.
Another condition that mimics an athlete's itch is called erythrasma . It is a bacterial infection that affects the groin and spreads down the inner thighs. However, the erythrasma rash is flat and brown all over the affected area. It is also free of flakes and blisters.
The best way to diagnose shingles is to look for hyphae (these tubular structures) under a microscope using the KOH test . The skin is scraped off with a scalpel or glass slide, causing dead skin cells to fall onto the slide. A few drops of potassium hydroxide (KOH) are added to the slide and the slide is heated for a short time. KOH dissolves the material that binds skin cells, releasing hyphae, but does not distort cells or hyphae. To see the hyphae better, you can use special dyes such as Chlorazole Fungus, Schwarz-Lamkins, or Blue Ink.
Athlete's itch is best treated with topical creams or ointments, as the fungus only affects the top layer of the skin (epidermis). Many antifungal medications require a prescription, but there are three that can be purchased without a prescription. … Over-the-counter antifungals:
- Terbinafine cream (Lamisil)
- Tolnaftate (tinactin)
- Clotrimazole (Lotrimin)
- Miconazole (mykatin)
Creams used to treat itchy skin should be applied twice a day for at least two weeks and can be discontinued after the rash is gone within a week.
Creams should be applied to the rash itself and also at least two fingers away from the rash. Many itchy people also have an athletic foot, and these same creams can be applied to the feet. However, it can take up to four weeks for mycosis to heal. If the rash is very red and itchy, especially with blisters around the edges, a topical steroid such as hydrocortisone can also be applied.
Steroids themselves should not be used in the groin without consulting a doctor, as steroids alone can significantly worsen rashes or itching.
There are several things you can do to prevent itching or recurrence in athletes.
- Wear loose-fitting cotton or synthetic clothing that will absorb surface moisture.
- Avoid sharing clothes, towels, or washcloths.
- After you shower, let your groin dry completely before putting on your underwear and clothing.
- Antifungal sprays or powders can be used once a day to prevent infection.