Jock itch

Definition
Jock itch, also known as tinea cruris, is a fungal infection of the skin in the groin area.

Causes/associated factors
Jock itch is caused by fungi that live on hair and dead tissues of the outer layer of skin. Because fungi thrive in warm, moist areas, fungal infections are often found in skin folds and places that are warm and tend to sweat a lot, such as the genital area. Jock itch can occur at any age, but it's rare before puberty. The condition is most common in males, athletes, people who are obese (because of additional skin folds) and those who have weak immune systems.
Your risk of developing jock itch increases if:

You have poor hygiene.
Your skin is continually moist (through sweat caused by summer heat, for example, or if you wear wet or tightly fitting clothing in the groin area).
Your skin receives a lot of friction.
You currently have tinea pedis (athlete's foot or ringworm of the feet).
You have a weakened immune system (due to diabetes, HIV or taking immunosuppressive drugs for cancer or an organ transplant, for example).

Transmission
Jock itch is mildly contagious. You can contract the condition through skin-to-skin contact, but it is rare for a woman to contract the infection from a sexual partner. Jock itch is also transmitted through sharing infected towels, bed linens or shower benches. Finally, you can also spread the disease from one body part of your body to another by touching the affected area and then touching another part of your body. This process is known as autoinoculation.

Signs/symptoms
Symptoms of jock itch include:
a red, ring-shaped and scaly rash with a darker, well-defined border that's confined to the groin, upper thighs or buttocks
a rash that usually spares the scrotum and penis
itching
skin irritation, especially if you scratch the rash

Diagnosis
Your doctor can diagnose jock itch with a physical exam. The doctor may use a special lamp to study your skin, and skin scrapings may be sent to a lab for analysis.

Treatment
An over-the-counter (OTC) topical antifungal medication -- a cream, lotion, spray or powder, such as miconazole (brand name Micatin), clotrimazole (Lotrimin) or miconazole in spray form (Cruex) -- may clear up the condition. If OTC remedies don't do the trick, your doctor may prescribe an antifungal medication, such as ketoconazole (Nizoral), naftifine (Naftin) or terbinafine (Lamisil). Oral (taken by mouth) griseofulvin may be prescribed when there is widespread infection.
In addition to taking your medication, keep your groin area dry. Wearing loose undergarments may also help.


Complications
Antifungal medications may irritate your skin. It's possible for fungus to develop a resistance to antifungal medications, so medication changes may be necessary. It's also common for jock itch to recur. If left untreated, jock itch fungal infections can become chronic. They may cause skin discoloration or lead to secondary bacterial or yeast infections.
Consult your doctor if:

You develop a fever.
The rash spreads rapidly.
The rash develops pus.
You have a weak immune system.

Pregnancy-specific information
Jock itch is uncommon in women. Pregnancy is not a risk factor for jock itch.

Senior-specific information
Older adults may be predisposed to jock itch through factors such as excess weight and immobility.

Prevention
If you have jock itch, avoid public showers, swimming pools and gyms until the infection clears up. To prevent jock itch:
Keep your groin area clean and dry.
Avoid scratching your groin area and excessive sweating, if possible.
Let your skin dry for 15 minutes after bathing or perspiring heavily before getting redressed.
Don't wear chafing or tightly fitting clothing (for example, wear boxer shorts instead of briefs).
Choose clothing made of cotton or other natural fibers. Avoid synthetic fabrics.
Wash athletic supporters and other exercise clothes in hot water.
Don't share clothing or towels.
Make sure household pets are evaluated and treated for suspected fungal infections