A new concept for the treatment of intractable pruritus ani.

To the Editor: Pruritus ani (PA) is an unpleasant sensation of itching and an urge to scratch the skin around the anal orifice. It is very common and a socially embarrassing condition which is often poorly managed. PA is classified as idiopathic when there is an absence of any apparent anorectal or colonic etiology, and secondary when PA is attributable to an identifiable etiology. The causes of secondary PA are numerous and include anorectal diseases such as fissures, proctitis, fistula, hemorrhoids, abscess, and malignant conditions such as rectal cancers and adenomatous polyps that can present initially with PA. A number of dermatologic skin lesions such as lichen planus, psoriasis, eczema, lichen sclerosis et atrophicus, and seborrhea are associated with PA. Infectious causes include Candida albicans, dermatophytes, Staphylococcus aureus, Corynebacterium minutissimum (erythrasma), group A [beta]-hemolytic Streptococcus, human Papillomavirus, herpes simplex, Enterobius vermicularis, and Sarcoptes scabiei. A number of medications have been reported to cause PA. They include colchicines, quinidine, mineral oil, and neomycin. Systemic disease such as diabetes mellitus and lymphoma can cause this annoying problem. Idiopathic PA is related to consumption of foods such as tomatoes, citrus fruits, nuts, chocolate, coffee, tea, cola, and beer. Irritants such as fecal soiling, excess moisture, soap, aggressive anal wiping, and scented toilet paper aggravate PA. Commonly, poor anal hygiene can be a setup for itching. The causes of PA may be difficult to determine, thus making it a potentially difficult condition to treat. It has also been suggested that psychological factors may play a role in the genesis of anal itching. (1) Though there is no difference in fecal microflora in patients with PA, it is thought that bacterial endopeptidases, exotoxins, and intestinal lysozymes act as irritating agents. (2) If the patient scratches, causing breaks in the sensitive perianal skin, these substances might penetrate into the dermis resulting in inflammation and release of irritating compounds. A vicious cycle of severe itching and scratching ensue. Many patients worsen the injury by cleaning the area with soaps and vigorous rubbing, or by applying topical medications that further irritate the skin. When PA does not respond to conservative therapy and when symptoms have existed for a long time, a high index of suspicion for the presence of malignancy should be maintained. (3) The management of PA is directed toward the underlying cause. It is estimated that 25 to 75% of patients with PA have an associated disorder. (4) A favorable response to specific medical therapy is seen in dermatologic conditions such as psoriasis, eczema, and mycotic dermatitis. Surgery also improves PA secondary to anorectal disorders such as fissures, extramammary Paget disease, fistulas, and abscesses.

A 48-year-old female was referred to the gastroenterology service for evaluation of rectal pain and itching. The patient stated that she had a spot in her rectum that flared up frequently, causing itching, burning, stinging, and bleeding. The skin around the anal region was excoriated. A skin biopsy of the perianal region was performed to rule out malignancy. It revealed squamous cell hyperplasia. We decided to proceed with a colonoscopy to rule out proximal colonic polyps or malignancy. Colonoscopy was positive only for internal hemorrhoids and diverticulosis coli. Her pruritus was refractory to general measures including anal hygiene, tranquilizers, and topical applications and suppositories of corticosteroids. At this point, patient was given the option to try intralesional corticosteroid injection. Eighty milligrams of methylprednisone acetate were injected into the perianal region at the site of excoriation. Three milliliters of 1% lidocaine were injected into the internal hemorrhoids. Patient had significant relief of pruritus and did not have a recurrence at the annual follow-up visit.

Intralesional corticosteroids are administered for a variety of dermatoses in which pruritus is the presenting symptom. Intralesional injection of corticosteroids could prove to be a promising treatment for persistent cases of PA resistant to currently used treatment regimens. The use of intralesional corticosteroids for idiopathic PA sufferers who fail all other treatments could be a simple alternative.

References

1. Laurent A, Boucharlat J, Bosson JL, et al. Psychological assessment of patients with idiopathic pruritus ani. Psychother Psychosom 1997;66:163-166.

2. Silverman SH, Youngs DJ, Allan A, et al. The fecal microflora in pruritus ani. Dis Colon Rectum 1989;32:466-468.

3. Nagle D, Rolandelii RH. Primary care office management of perianal and anal disease. Prim Care 1996;23:609-620.

4. Bowyer A, McColl I. A study of 200 patients with pruritus ani. Proc R Soc Med 1970;63:96-98.

Anuradha Tunuguntla, MD

Department of Internal Medicine

East Tennessee State University 

Johnson City, TN

Michael J. Sullivan, MD

Sullivan Digestive Center

Kingsport, TN

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