Pruritus Ani (Anal Itching)

History of present illness should note whether the problem is acute or recurrent. The patient should be asked about topical agents applied to the anus, including wipes, ointments (even those used to treat itching), sprays, and soaps. Diet and drug profiles should be reviewed for causative agents (see table ), particularly acidic or spicy foods. A general sense of hygiene should be obtained by asking about frequency of showers and baths.

Review of systems should seek symptoms of causative disorders, including urinary or fecal incontinence (local irritation), anal pain or lump, blood on toilet paper (hemorrhoids), bloody diarrhea and abdominal cramps (inflammatory bowel disease), and skin plaques (psoriasis).

Past medical history should identify known conditions associated with pruritus ani, particularly prior anorectal surgery, hemorrhoids, and diabetes.

General examination should be done to obtain a sense of overall hygiene and note any signs of anxiety or obsessive-compulsive behavior.

Physical examination is focused on the anal region, particularly looking for perianal skin changes, signs of fecal staining or soilage (suggesting inadequate hygiene), and hemorrhoids. External inspection should also note the integrity of the perianal skin, whether it appears dull or thickened (suggesting chronicity), and the presence of any cutaneous lesions, fistulas, excoriations, or signs of local infection. Sphincter tone is assessed by having the patient contract the sphincter during digital rectal examination. The patient should then be asked to bear down as if for a bowel movement, which may show prolapsing internal hemorrhoids. Anoscopy may be necessary to further evaluate the anorectum for hemorrhoids.

Dermatologic examination may reveal scabies burrows in the interdigital webbing or scalp or signs of any other contributing systemic skin disease.

The following findings are of particular concern:

Hygiene issues, use of topical agents, and local disorders (eg, candidal infection Candidiasis (Mucocutaneous) Candidiasis is skin and mucous membrane infection with Candida species, most commonly Candida albicans. Infections can occur anywhere and are most common in skinfolds, digital... read more , hemorrhoids Hemorrhoids Hemorrhoids are dilated vessels of the hemorrhoidal plexus in the anal canal. Symptoms include irritation and bleeding. Thrombosed hemorrhoids are usually painful. Diagnosis is by inspection... read more ) are usually apparent by history and examination.

In adults with acute itching without obvious cause, ingested substances should be considered; a trial of eliminating these substances from the diet may be useful. In children, pinworms should be suspected.

In adults with chronic itching and no apparent cause, overly aggressive anal hygiene may be involved.

For many patients, a trial of empiric, nonspecific therapy is appropriate unless particular findings are noted. For example, biopsy, culture, or both of visible lesions of uncertain etiology should be considered. If pinworms, which occur most often in school-aged children, are suspected, eggs can be detected Diagnosis Enterobiasis is an intestinal infestation by the pinworm Enterobius vermicularis, usually in children, but adult members of their household and caregivers, institutionalized people, and... read more by patting the perianal skinfolds with a strip of cellophane tape in the early morning; the tape is placed sticky side down on a glass slide and viewed microscopically.