II. Epidemiology

  1. Prevalence: 1-5% of population in the United States

III. Causes

  1. Systemic causes
    1. Diabetes Mellitus
    2. Hyperbilirubinemia
    3. Leukemia
    4. Lymphoma
    5. Aplastic Anemia
    6. Thyroid disease
    7. Lumbosacral Radiculopathy (especially elderly)
    8. Inflammatory Bowel Disease
  2. Functional and mechanical causes
    1. Chronic Diarrhea
    2. Chronic Constipation
    3. Anal Fissure
    4. Anal fistula
    5. Tight fitting clothes
    6. Vigorous peri-anal cleaning
    7. Stool Leakage
      1. Anal Incontinence
      2. Prolapsed Hemorrhoids
      3. Rectal Prolapse
      4. Anal papilloma (HPV)
      5. Skin Tags
  3. Infections
    1. Erythrasma (Corynebacterium)
    2. Intertrigo (Candida)
    3. Herpes Simplex Virus (HSV)
    4. Human Papillomavirus (HPV)
    5. Pinworms or Enterobius (Especially young children)
    6. Scabies
    7. Perirectal Abscess
    8. Gonorrhea
    9. Syphilis
    10. Molluscum Contagiosum
    11. Condyloma (perianal wart)
  4. Dermatologic causes
    1. Psoriasis
    2. Contact Dermatitis (see below)
    3. Hidradenitis Suppurativa
    4. Seborrheic Dermatitis
    5. Intertrigo
    6. Neurodermatitis
    7. Bowen Disease or Squamous Cell Carcinoma
    8. Extramammary Paget Disease
    9. Atopic Dermatitis
    10. Lichen Planus
    11. Lichen Sclerosis
  5. Exposures
    1. Systemic: Medications
      1. Colchicine
      2. Quinidine
      3. Neomycin
      4. Chemotherapy
    2. Topicals: Contact Dermatitis
      1. Soaps, deodorants or perfumes
      2. Alcohol-based anal wipes
      3. Allergy to dyes or perfumes in toilet paper
      4. Fabric softener use
      5. Talcum powder
      6. Suppositories
    3. Topicals: Food irritants
      1. Tomatoes
      2. Chili peppers
      3. Caffeinated beverages
      4. Beer
      5. Citrus juices or fruit
      6. Milk products

IV. Signs

  1. See Anorectal Exam
  2. Findings suggestive of cause
    1. Intertrigo
    2. Prolapsed Hemorrhoid
    3. Anal Fissure
    4. Perianal Condyloma
    5. Fistula
  3. Complications of chronic scratching
    1. Excoriations
    2. Perianal skin lichenification

V. Labs (as indicated based on history and exam)

  1. Pinworm Test
  2. Anal biopsy
    1. Indicated only in refractory cases without clear etiology

VI. Evaluation

  1. Initiate therapy (see below) and see for follow-up after 4-6 weeks
    1. Conservative therapy is effective in 89% of patients
  2. Failure to improve (11% of cases) should prompt further evaluation for underlying cause
    1. Contributory underlying anorectal disease (52%)
    2. Lower endoscopy abnormality (35%)
    3. Underlying neoplasm (23%)
  3. References
    1. Daniel (1994) Dis Colon Rectum 37(7):670-4 [PubMed]

VII. Management

  1. Eliminate itch-scratch cycle (especially while asleep)
  2. Eliminate exacerbating factors (see causes above)
    1. Critical to keep the perianal area dry
    2. Avoid excessive wiping and Alcohol wipes
    3. Wear loose clothing
    4. Dietary changes (eliminate coffee, milk, beer, nuts)
  3. Perianal cleaning (gentle)
    1. Wash twice daily with water and sensitive soap
    2. Clean with handheld shower head, squirt bottle, sitz bath or bidet
  4. Medications
    1. Hydroxyzine (Atarax or Vistaril) 50 mg at bedtime (adults)
    2. Topical 5% Lidocaine (Xylocaine) ointment
    3. Low potency Topical Corticosteroid
      1. Use briefly as last resort only
      2. Hydrocortisone 1% applied to area for 2-4 weeks
      3. Avoid high potency Corticosteroids
      4. Avoid use longer than 4 weeks
      5. Al-Ghaniem (2007) Int J Colorectal Dis 22(12):1463-7 [PubMed]
    4. Capsaicin 0.006% cream
      1. Requires compounding - dilute standard Capsaicin in white paraffin
      2. Lysy (2003) Gut 52(9): 1323-6 [PubMed]

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Ontology: Pruritus Ani (C0033775)

Definition (MSH) Intense chronic itching in the anal area.
Concepts Sign or Symptom (T184)
MSH D011538
ICD9 698.0
ICD10 L29.0
SnomedCT 201012005, 156381007, 90446007
English Pruritus Ani, PERIANAL ITCHING, PRURITUS ANI, pruritus ani (diagnosis), anal itching, pruritus ani, anal itching (symptom), rectal pruritus, anal pruritus, rectal itching, rectal itching (symptom), Perianal irritation, Perianal itching, itching in anal region, pruritus in the anal region, itching in anal region (symptom), Pruritus perineal, perianal itching, Pruritus Ani [Disease/Finding], ani pruritis, itch anal, Itching;anal, pruritus anal, anis pruritus, irritations perianal, Itching;perianal, Itching;rectal, Pruritus;perianal, itching anal, rectal itch, itching perianal, anal itch, ani pruritus, perianal pruritus, itching rectal, pruritis ani, Anal pruritus, Pruritus ani, Anal itch, Perianal itch, Pruritus ani (disorder), itch; anal, pruritus; ani, anal; itch, ani; pruritus, Pruritus ani (finding), pruritis of perianal region
French PRURIT ANAL, Prurit périnéal, Irritation périnéale, Démangeaisons périanales, DEMANGEAISONS ANALES, Prurit anal, Prurit de l'anus
Portuguese PRURIDO ANAL, Prurido perineal, Irritação perianal, PRURIDO PERIANAL, Prurido anal, Prurido Anal
Spanish PRURITO ANAL, Prurito perineal, Irritación perianal, Prurito anal, Pruritus ani, Picor perianal, PRURITO PERIANAL, prurito anal, prurito del ano, prurito perianal, prurito del ano (hallazgo), prurito del ano (trastorno), Prurito Anal
German PRURITUS ANI, Pruritis perianal, analer Juckreiz, perianale Reizung, perianales Jucken, PERIANALER JUCKREIZ, Afterjucken, Pruritus ani
Dutch pruritus aan bilnaad, pruritus ani, perianale jeuk, anale pruritus, perianale irritatie, anaal; jeuk, ani; pruritus, jeuk; anaal, pruritus; ani, Perianale jeuk, Pruritus ani
Italian Prurito perineale, Prurito perianale, Irritazione perianale, Prurito anale
Japanese 会陰部そう痒症, エインブソウヨウショウ, 肛門そう痒症, コウモンシュウイシゲキショウジョウ, コウモンソウヨウショウ, 肛門周囲そう痒, コウモンシュウイソウヨウショウ, 肛門周囲そう痒症, 肛門周囲刺激症状, コウモンシュウイソウヨウ
Swedish Klåda i ändtarmsmynningen
Czech pruritus ani, Perianální svědění, Řitní svědění, Pruritus hráze, Anální pruritus, Perianální dráždění, svědění konečníku, svědění řiti
Finnish Peräaukon kutina
Russian ANUSA ZUD, АНУСА ЗУД
Korean 항문가려움
Polish Świąd odbytu
Hungarian Perinealis viszketés, Perianalis viszketés, Végbélviszketés, Anális viszketés, Perianalis irritatio
Norwegian Pruritus ani, Analkløe, Kløe i endetarmsåpningen