Pruritus Ani

Anogenital Pruritus

What is pruritus ani?

Pruritus ani is severe itching of the skin around the external genitals or anus. The itching seems to be particularly noticeable at night while the person is trying to sleep.

Pruritus ani can be caused by many things including pinworms (parasites), bacterial infections, diet, reactions to oral antibiotics, and underlying (systemic) disease conditions of the body such as diabetes mellitus.

Skin conditions in the anal area that may contribute to pruritus ani include fungus, a condition causing an intensely itchy patch of bumps (lichen simplex chronicus), or inflammation between folds of skin caused by warmth mixed with moisture (intertrigo).

It may also be caused by irritating substances coming in contact with the skin (contact dermatitis) such as diarrhea, colon or vaginal secretions, or detergents that remain in underclothing.

Trauma or injury to the anal area, a defective anal muscle (incompetent anal sphincter), an abnormal opening (fistula), and hemorrhoids are often associated with pruritus ani.

Other contributing factors may be either poor hygiene or too vigorous cleaning of the area.

How is it diagnosed?

History: There may be no other symptoms than severe itching of the anal area.

Physical exam may reveal any of the following: red, irritated skin, bumps, an unusual thickening or softening of the skin, and scratches or breaks in the skin from scratching. Hemorrhoids, fistula, or evidence of an incompetent anal sphincter may also be present. Females should also undergo a gynecological exam to rule out any underlying disease process, such as vaginitis.

Tests should be done to determine whether pruritus ani is the result of a systemic disease or from local causes. Tests may include blood glucose levels, blood nitrogen levels, ERS, hemochrome, liver (hepatic) functions, analysis of feces, and a skin biopsy. An examination of the inside of the rectum and lower colon is done using a viewing tube inserted through the anus (proctocolonoscopy).

Because there are so many possible causes of pruritus ani, it is very important that it is diagnosed and treated accurately.

How is pruritus ani treated?

To be effective, treatment must match the cause. Parasites or bacterial infections can be treated with medication. Underlying disease processes (such as diabetes mellitus) need treatment. Injuries, fistulas, and hemorrhoids need to be medically addressed. Allergic reactions can be avoided by changing soaps or detergents, or by additional rinsing of clothes after washing to remove soap residue.

Diet changes include avoiding spices, coffee, tea, cola, beer, chocolate, tomatoes, and citrus fruits. Poor hygiene needs to be corrected. On the other hand, too vigorous cleansing needs to be modified by stopping the use of over-the-counter preparations, cleaning pads, and solutions. Use of a blow dryer on the perineum may be used. Water, alone, may be adequate hygiene for over-sensitive skin.

For cases where the cause is never determined (idiopathic), injection of a medication under the skin of the affected area may be curative.

Individual should be reexamined again in two to three weeks to evaluate effectiveness of treatment.


Brand Generic Label Rating
Paroxetine online Paxil Paroxetine Off-Label
Generic Amitriptyline online Elavil Amitriptyline Off-Label

Zofran (Ondansetron), Periactin (Cyproheptadine), Phenergan (Promethazine), Clarinex (Desloratadine), Atarax (Hydroxyzine), Revia (Naltrexone)

What might complicate it?

Severe excoriation, ulceration and secondary infection of the perineum are complications. The presence of hemorrhoids, an anal fistula, incompetent anal sphincter, or an underlying disease process might complicate pruritus ani.

Predicted outcome

If the cause can be determined and effectively treated, pruritus ani can be eliminated. Symptoms can be lessened or eliminated in idiopathic cases through use of injected medication.


Hemorrhoids, fistula, fissures, tumors of the anorectum, infections, contact dermatitis, psoriasis, Bowen's disease or Paget's disease are other possibilities.

Appropriate specialists

Proctologist, gastroenterologist, gynecologist, and dermatologist.

Notify your physician if

  • You or a family member has symptoms of pruritus ani that persist, despite self-care.
  • Fever occurs.
  • The irritated area seems infected.

Last updated 21 December 2011

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