Rectal Pain or Itching

You have dry, itchy skin in the crease between your buttocks. Your problem is likely to be caused by one of several conditions:

Psoriasis

Psoriasis is a recurring rash caused by a variation in your immune system. It very commonly causes a rash in the buttock crease, and it also most commonly affects the scalp, the ear, the groin, and the elbows and knees. Psoriasis causes the skin to appear red and thickened with a white or silvery crust. Many treatments are effective, ranging from skin creams to ultraviolet light exposure and oral medicines.

"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.

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.

Scabies

Scabies are mites that can infect your skin. Scabies are very contagious. Scabies can cause a rash and itching outside of the groin and buttock area, even if the infestation is localized to this area.

Pilonidal cyst

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 and infected pilonidal cysts usually require the attention of a surgeon and do not heal permanently on their own. Pilonidal cysts that are less symptomatic may not need any treatment.

Seborrheic dermatitis

Seborrheic dermatitis can cause a greasy red rash with some yellow crusts. If you have seborrheic dermatitis in your buttock crease, you probably have also noticed a similar rash at your scalp line or on your face or chest. Dandruff is a form of seborrheic dermatitis.

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.

Molluscum contagiosum

Molluscum contagiosum is a viral rash that creates small flesh-colored bumps on the skin. It spreads from one person to the next during sexual contact.