Rectal Pain or Itching

Since you have moisture within your buttock crease, this is the likely cause of your itching. But what is causing your moisture? There are several likely possibilities.

Draining pilonidal cyst (Pilonidal sinus)

Where your skin and tissue fold inward at the top of your buttock crease, a hair can easily become ingrown so that its tip re-enters the skin and creates irritation. Doctors think that is a likely reason that the buttock crease can develop a pilonidal cyst, which is an irritated pocket of fluid and hairs under the skin surface. Pilonidal cysts are most common in men under age 40, and they are more likely to occur in people with abundant body hair. Pilonidal cysts that become infected can cause pain and may create an area on the overlying skin surface that is red, tender, and swollen. A pilonidal cyst can develop one or more draining holes to the skin surface, creating a constant discharge of blood, pus, or clear fluid. A cyst with a draining hole is known as a pilonidal sinus. Pilonidal sinuses usually require the attention of a surgeon and do not heal permanently on their own.

Hidradenitis suppurativa

Blockage of a hair follicle can allow sweat glands just beneath the hair root to become congested and inflamed. When this occurs, the sweat glands can deteriorate and combine into pockets of fluid under the skin. This can make the skin look as if it has acne, it can cause scarring, and it can cause you to form repeated "boils" (pockets of pus underneath the skin). If you have a lot of problems from congestion and inflammation of your sweat glands, your condition is called "hidradenitis suppurativa" (also known as "acne inversus"). Antibiotics may be helpful; large boils may require drainage by your doctor.

"Jock itch" (tinea cruris)

Tinea is a fungus infection of the skin, and it commonly affects the groin, upper thigh, and buttock crease. Tinea of the groin is named "tinea cruris" or jock itch. A tinea infection appears as a bright red or red-brown patch of skin with a well-defined boundary. This rash is very itchy.

Yeast infection (candidiasis)

Yeast infections can cause an itchy or painful red rash on the skin. It is most common for a yeast infection to affect the skin in the folds of the groin (at the top of the thigh) and the skin around the genitals, but it may also occur in the anus area or the buttock crease.

Sweating

Sweat may collect in creases. Well-ventilated clothing and frequent showers may help.