Rectal Pain or Itching

Since you have moisture around your anus, this is the likely cause of your itching. But what is causing your moisture? There are several possibilities that are worth considering, either because they are common or because they would be a cause for serious concern.

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.

Anal fistula

Injury or inflammation in the lining of the rectum may permit bacteria to contaminate one of the mucus glands that surround the rectum. When a mucus gland becomes infected, the infection may quickly intensify to create a pocket of pus (anal abscess). An anal abscess may drain pus through a break in the skin. An abscess can also drain pus through a break in the rectum lining. A draining pathway to the skin or rectum wall can persist for a long time without healing. A draining pathway that has not healed is called an anal fistula. An anal fistula usually causes a moist discharge of pus from the rectum or skin. A fistula may look like an open sore or a pus-filled bump near the anus. An anal fistula must be treated by a surgeon in order to heal.

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.

Sweating

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

Anal cancer

Cancer at the rim of the anus is sometimes the result of a sexually passed infection, human papillomavirus. Anal cancer is more likely to result from this virus if you are infected with HIV (human immunodeficiency virus). Anal cancer may look like a skin sore that will not heal. It commonly causes bleeding with bowel movements.

Syphilis

Syphilis can cause a moist rash with lumpy or thickened skin in the anal or genital area. Syphilis is a sexually transmitted infection. If any itching occurs, it will be mild.