Pruritus ani

Irritation of the skin of the anus, causing itching

Medical condition

Pruritus ani

Specialty| Dermatology

Pruritus ani is the irritation of the skin at the exit of the rectum, known as the anus, causing the desire to scratch.[1] The intensity of anal itching increases from moisture,[2] pressure, and rubbing caused by clothing and sitting. At worst, anal itching causes intolerable discomfort that often is accompanied by burning and soreness. It is estimated that up to 5% of the population of the United States experiences this type of discomfort daily.

## Causes

[edit]

If a specific cause for pruritus ani is found it is classified as "secondary pruritus ani". If a specific cause is not found it is classified as "idiopathic pruritus ani".[3] The irritation can be caused by intestinal parasites, anal perspiration, frequent liquid stools, diarrhea, residual stool deposits, or the escape of small amounts of stool as a result of incontinence or flatulence. Another cause is yeast infection or candidiasis. Some diseases increase the possibility of yeast infections, such as diabetes mellitus or HIV infection. Treatment with antibiotics can bring about a disturbance of the natural balance of intestinal flora, and lead to perianal thrush, a yeast infection affecting the anus. Psoriasis also can be present in the anal area and cause irritation. Abnormal passageways (fistulas) from the small intestine or colon to the skin surrounding the anus can form as a result of disease (such as Crohn's disease), acting as channels which may allow leakage of irritating fluids to the anal area. Other problems that can contribute to anal itching include pinworms, hemorrhoids, tears of the anal skin near the mucocutaneous junction (fissures), and skin tags (abnormal local growth of anal skin). Aside from diseases relative to the condition, a common view suggests that the initial cause of the itch may have passed, and that the illness is in fact prolonged by what is known as an itch-scratch-itch cycle.[4][5] It states that scratching the itch encourages the release of inflammatory chemicals, which worsen redness, intensifies itchiness and increases the area covered by dry skin, thereby causing a snowball effect.

Some authorities describe “psychogenic pruritus” or "functional itch disorder",[6] where psychological factors may contribute to awareness of itching.

Ingestion of pinworm eggs leads to enterobiasis, indicative of severe itching around the anus from migration of gravid females from the bowel. Severe cases of enterobiasis result in hemorrhage and eczema.

## Diagnosis

[edit]

Diagnosis is usually done with a careful examination of the anus and the patient's history. If the presentation or physical findings are atypical, ie change in bowel habits or personal/family history of colorectal cancer/adenomas, a colonoscopy should be proposed.[7]

In case of long-lasting symptoms, above all in patients over 50 years of age, a colonoscopy is useful to rule out a colonic polyp or tumor, that can show pruritus ani as first symptom.[8]

## Treatment

[edit]

The goal of treatment is asymptomatic, intact, dry, clean perianal skin with reversal of morphological changes. For pruritus ani of unknown cause (idiopathic pruritus ani)[3] treatment typically begins with measures to reduce irritation and trauma to the perianal area.[9] Stool softeners can help prevent constipation.[9] If this is not effective topical steroids or injected methylene blue may be tried. Another treatment option that has been met with success in small-scale trials is the application of a very mild (0.006%) topical capsaicin cream.[10] This strength cream is not typically commercially available and therefore must be diluted by a pharmacist or end-user. If the itchiness is secondary to another condition such as infection or psoriasis these are typically treated.[9]

A successful treatment option for chronic idiopathic pruritus ani has been documented using a clean, dry and apply (if necessary) method. The person is instructed to follow this procedure every time the urge to scratch occurs. The treatment makes the assumption that there is an unidentified bacteria in the feces that causes irritation and itching when the feces makes contact with the anal and perianal skin during defecation, flatulation or anal leakage (particularly during sleep).

For otherwise idiopathic, intractable cases, a double-blind trial with 44 patients found that capsaicin may be an effective treatment. By applying topical capsaicin mixed with paraffin wax (both available over the counter) with a concentration of 0.006% to the perianal area every 1-2 days, approximately three quarters of patients reported total (or near-total) relief of symptoms. [11]

## See also

[edit]

* Pruritus scroti
* Pruritus vulvae
* Perianal candidiasis

## References

[edit]

1. ^ James WD, Berger T, Elston D (2006). Andrews' Diseases of the Skin: Clinical Dermatology (10th ed.). Philadelphia: Saunders Elsevier. ISBN 978-0-7216-2921-6. [page needed]
2. ^ "Pruritus Ani". American Society of Colon & Rectal Surgeons. 2008. Archived from the original on March 21, 2008.
3. ^ a b Song SG, Kim SH (April 2011). "Pruritus ani". Journal of the Korean Society of Coloproctology. 27 (2): 54–57\. doi:10.3393/jksc.2011.27.2.54. PMC 3092075. PMID 21602962.
4. ^ "Itchy skin". NHS. 19 January 2018.
5. ^ Pfenninger JL, Zainea GG (June 2001). "Common anorectal conditions: Part I. Symptoms and complaints". American Family Physician. 63 (12): 2391–2398\. PMID 11430454.
6. ^ Misery L, Alexandre S, Dutray S, Chastaing M, Consoli SG, Audra H, et al. (2007). "Functional itch disorder or psychogenic pruritus: suggested diagnosis criteria from the French psychodermatology group". Acta Dermato-Venereologica. 87 (4): 341–344\. doi:10.2340/00015555-0266. PMID 17598038.
7. ^ Jakubauskas, Matas; Dulskas, Audrius (2023-02-02). "Evaluation, management and future perspectives of anal pruritus: a narrative review". European Journal of Medical Research. 28 (1): 57. doi:10.1186/s40001-023-01018-5. ISSN 2047-783X. PMC 9892672. PMID 36732860.
8. ^ Pata F (2017). "Pruritus ani: the neglected stepchild of Coloproctology" (PDF). Società Italiana di Chirurgia Colo Rettale. 45: 383–395.
9. ^ a b c Markell KW, Billingham RP (February 2010). "Pruritus ani: etiology and management". The Surgical Clinics of North America. 90 (1): 125–35, Table of Contents. doi:10.1016/j.suc.2009.09.007. PMID 20109637.
10. ^ Lysy J, Sistiery-Ittah M, Israelit Y, Shmueli A, Strauss-Liviatan N, Mindrul V, et al. (September 2003). "Topical capsaicin--a novel and effective treatment for idiopathic intractable pruritus ani: a randomised, placebo controlled, crossover study". Gut. 52 (9): 1323–1326\. doi:10.1136/gut.52.9.1323. PMC 1773800. PMID 12912865.
11. ^ Lysy, J.; Sistiery-Ittah, M.; Israelit, Y.; Shmueli, A.; Strauss-Liviatan, N.; Mindrul, V.; Keret, D.; Goldin, E. (September 2003). "Topical capsaicin—a novel and effective treatment for idiopathic intractable pruritus ani: a randomised, placebo controlled, crossover study". Gut. 52 (2003 Sep): 1323–1326\. doi:10.1136/gut.52.9.1323. PMC 1773800. PMID 12912865.

## External links

[edit]

* Siddiqi S, Vijay V, Ward M, Mahendran R, Warren S (September 2008). "Pruritus ani". Annals of the Royal College of Surgeons of England. 90 (6): 457–463\. doi:10.1308/003588408X317940. PMC 2647235. PMID 18765023.

Classification|

* ICD-10: L29.0
* ICD-9-CM: 698.0
* MeSH: D011538
* DiseasesDB: 30154

|

* v
* t
* e

Diseases of the human digestive system

Upper GI tract|

| Esophagus|

* Esophagitis
* Candidal
* Eosinophilic
* Herpetiform
* Rupture
* Boerhaave syndrome
* Mallory–Weiss syndrome
* Zenker's diverticulum
* Barrett's esophagus
* Esophageal motility disorder
* Nutcracker esophagus
* Achalasia
* Esophagogastric junction outflow obstruction
* Diffuse esophageal spasm
* Gastroesophageal reflux disease (GERD)
* Laryngopharyngeal reflux (LPR)
* Esophageal stricture
* Inlet patch
* Megaesophagus
* Esophageal intramural pseudodiverticulosis
* Acute esophageal necrosis

|

Stomach|

* Gastritis
* Atrophic
* Ménétrier's disease
* Gastroenteritis
* Peptic (gastric) ulcer
* Cushing ulcer
* Dieulafoy's lesion
* Dyspepsia
* Functional dyspepsia
* Pyloric stenosis
* Achlorhydria
* Gastroparesis
* Gastroptosis
* Portal hypertensive gastropathy
* Gastric antral vascular ectasia
* Gastric dumping syndrome
* Gastric volvulus
* Buried bumper syndrome
* Gastrinoma
* Zollinger–Ellison syndrome

Lower GI tract
Enteropathy|

| Small intestine
(Duodenum/Jejunum/Ileum)|

* Enteritis
* Duodenitis
* Jejunitis
* Ileitis
* Peptic (duodenal) ulcer
* Curling's ulcer
* Malabsorption: Coeliac
* Tropical sprue
* Blind loop syndrome
* Small intestinal bacterial overgrowth
* Whipple's
* Short bowel syndrome
* Steatorrhea
* Milroy disease
* Bile acid malabsorption

|

Large intestine
(Appendix/Colon)|

* Appendicitis
* Colitis
* Pseudomembranous
* Ulcerative
* Ischemic
* Microscopic
* Collagenous
* Lymphocytic
* Dysentery
* Functional colonic disease
* IBS
* Intestinal pseudoobstruction / Ogilvie syndrome
* Megacolon / Toxic megacolon
* Diverticulitis/Diverticulosis/SCAD

Large and/or small|

* Enterocolitis
* Necrotizing
* Gastroenterocolitis
* IBD
* Crohn's disease
* Vascular: Abdominal angina
* Mesenteric ischemia
* Angiodysplasia
* Bowel obstruction: Ileus
* Intussusception
* Volvulus
* Fecal impaction
* Constipation
* Functional
* Diarrhea
* Infectious
* Intestinal adhesions

Rectum|

* Proctitis
* Radiation proctitis
* Proctalgia fugax
* Rectal prolapse (Internal rectal prolapse)
* Anismus
* Solitary rectal ulcer syndrome
* Rectal stricture

Anal canal|

* Anal fissure/Anal fistula
* Anal abscess
* Hemorrhoid
* Anal dysplasia
* Pruritus ani
* Anal stricture

GI bleeding|

* Blood in stool
* Upper
* Hematemesis
* Melena
* Lower
* Hematochezia

Accessory|

| Liver|

* Hepatitis
* Viral hepatitis
* Autoimmune hepatitis
* Alcoholic hepatitis
* Cirrhosis
* PBC
* Fatty liver
* MASLD
* Vascular
* Budd–Chiari syndrome
* Hepatic veno-occlusive disease
* Portal hypertension
* Nutmeg liver
* Alcoholic liver disease
* Liver failure
* Hepatic encephalopathy
* Acute liver failure
* Liver abscess
* Pyogenic
* Amoebic
* Hepatorenal syndrome
* Peliosis hepatis
* Metabolic disorders
* Wilson's disease
* Hemochromatosis

|

Gallbladder|

* Cholecystitis
* Gallstone / Cholelithiasis
* Cholesterolosis
* Adenomyomatosis
* Postcholecystectomy syndrome
* Porcelain gallbladder

Bile duct/
Other biliary tree|

* Cholangitis
* Primary sclerosing cholangitis
* Secondary sclerosing cholangitis
* Ascending
* Cholestasis/Mirizzi's syndrome
* Biliary fistula
* Haemobilia

* Common bile duct
* Choledocholithiasis
* Biliary dyskinesia
* Sphincter of Oddi dysfunction

Pancreatic|

* Pancreatitis
* Acute
* Chronic
* Hereditary
* Pancreatic abscess
* Pancreatic pseudocyst
* Exocrine pancreatic insufficiency
* Pancreatic fistula

Other|

| Hernia|

* Diaphragmatic
* Congenital
* Hiatus

* Inguinal
* Indirect
* Direct
* Umbilical
* Paraumbilical
* Femoral
* Obturator
* Spigelian

* Lumbar
* Petit's
* Grynfeltt–Lesshaft

* Undefined location
* Incisional
* Internal hernia
* Richter's

|

Peritoneal|

* Peritonitis
* Spontaneous bacterial peritonitis
* Hemoperitoneum
* Pneumoperitoneum

* v
* t
* e

Dermatitis and eczema

Atopic dermatitis|

* Prurigo gestationis
* Sweat allergy

Seborrheic dermatitis|

* Pityriasis simplex capillitii
* Cradle cap

Contact dermatitis
(allergic, irritant)|

* plants: Urushiol-induced contact dermatitis
* African blackwood dermatitis
* Tulip fingers

* other: Abietic acid dermatitis
* Diaper rash
* Airbag dermatitis
* Baboon syndrome
* Contact stomatitis
* Metal allergy
* Protein contact dermatitis

Eczema|

* Autoimmune estrogen dermatitis
* Autoimmune progesterone dermatitis

* Breast eczema
* Ear eczema
* Eyelid dermatitis
* Topical steroid withdrawal
* Hand eczema
* Dyshidrosis
* Hyperkeratotic hand dermatitis
* Autosensitization dermatitis/Id reaction
* Candidid
* Dermatophytid
* Molluscum dermatitis
* Circumostomy eczema
* Juvenile plantar dermatosis
* Nummular eczema
* Nutritional deficiency eczema
* Sulzberger–Garbe syndrome
* Xerotic eczema

Pruritus/Itch/
Prurigo|

* Lichen simplex chronicus/Prurigo nodularis

* by location: Pruritus ani
* Pruritus scroti
* Pruritus vulvae
* Scalp pruritus

* Drug-induced pruritus
* Hydroxyethyl starch-induced pruritus
* Senile pruritus
* Aquagenic pruritus
* Aquadynia

* Adult blaschkitis
* due to liver disease
* Biliary pruritus
* Cholestatic pruritus
* Prion pruritus
* Prurigo pigmentosa
* Prurigo simplex
* Puncta pruritica
* Uremic pruritus

Other|

* substances taken internally: Bromoderma
* Fixed drug reaction

* Nummular dermatitis
* Pityriasis alba
* Papuloerythroderma of Ofuji

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