Pruritus Ani
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Sandyford Protocols PRURITUS ANI Aetiology Inflammatory dermatoses: seborrhoeic eczema, flexural psoriasis, contact dermatitis (allergy), lichen sclerosis, lichen planus (may be no sign of skin disease elsewhere) Infection: viral warts, fungal infection (candida and dermatophyte species), erythrasma (Corynebacterium minutissimum), herpes simplex and zoster Parasitic infections: threadworms especially in children Metabolic problems: diabetes mellitus Malignancy: perianal carcinoma, extra mammary Paget's disease Poor hygiene: obesity and skin tags Anal leakage: sphincter dysfunction Stress: chronic lichen simplex History Symptoms of itching or pain: identify aggravating or relieving factors General health including medications and allergies: enquire about bowel history, use of creams and ointments, problems with rest of skin and mucous membranes including mouth, vagina and glans penis. Family history : diabetes, bowel problems Social history : recent travel abroad and sexual health Physical Examination Skin and perianal area: assess overall skin morphology and condition, taking into account hairiness, faecal soiling, eczema, lichenification, ulceration, fissures, skin tags, fistula and sinuses Rectal examination (consider digital and proctoscopic exam) Skin: assess remainder of integument for clinical clues (psoriatic nails, Wickham’s striae) Investigations Swabs to exclude infection: ulcer PCR swab if fissures,ulcers or unusual erythematous lesions, in addition to bacteriology charcoal swab of affected area Apply cellotape for threadworm ova apply sticky side to perianal area in the morning before defaecation. Tape is then applied to a slide for microscopic examination. Urinalysis for glucose Consider skin biopsy and patch testing PRURITUS ANI CEG SEPT 2015 Page 1 of 3 Sandyford Protocols Management General Advice Clean carefully after bowel motions Use appropriate soap substitute cream by hand (avoid soap, bubblebaths, shampoo, other potential irritative applications and abrasive agents such as flannels) Wear loose soft cotton underwear Eat high fibre diet (avoid trauma by facilitating normal anal sphincter function)) Lose weight if appropriate Avoid spicy foods or other irritant foods Try not to scratch: trial of cotton gloves at night. Specific conditions Threadworm Enterobius vermicularis - small white thread-like (1-2cm) worms Females lay eggs in perianal region which are ingested and mature in the caecum ( 6 weeks incubation) Sources of infection: digital/anal/oral contact bedding (households/institutions) rimming (especially MSM) Mebendazole 100 mg stat May need second dose after 3 weeks if recurrence *Avoid in pregnancy – SEE BELOW A rigid regime of personal hygiene with the hope of “natural eradication” should be attempted, treating all other members of the family, in addition to aqueous cream perianally. No treatment is licensed in pregnancy. Other causes Erythrasma: chronic, itchy, red-brown macules with very fine scale on intertriginous skin, particularly the anogenital area. Treat using erythromycin 500mg bd po for 5-7 days, or topical 2% clindamycin cream for one week. Acute Anal Fissure: The majority of acute fissure tears are posterior (>99% in men, >90% women). If multiple fissures and/or atypical location consider alternative diagnosis – HSV, syphilitic chancre, inflammatory bowel disease (Crohn’s, ulcerative colitis), intra- epithelial neoplasia (AIN), trauma. Usual presentation is acute pain; however, anal itch is also common. Recommend: 1. Laxatives (discuss stimulant versus bulking type) 2. Dietary adjustments – fruit/fibre/fluids 3. non-constipating analgesics (paracetamol – avoid NSAIDs) 4. topical anaesthetic (short term use only – anusol proprietary preparation) PRURITUS ANI CEG SEPT 2015 Page 2 of 3 Sandyford Protocols 5. Glyceryl trinitrate cream (Rectogesic 0.4% GTN: apply 2.5 cm twice daily for up to 8 weeks - non formulary) may also be useful (warn patient on risk of vasovagal episodes due to low blood pressure, headache and potential interactions with other blood pressure-lowering drugs). Diltiazem cream is used as an alternative for patients who are intolerant of GTN. Reassure that the majority of fissures are self-limiting and unlikely to cause serious long term harm to health. Recurrent and chronic fissures may also be managed by surgical intervention. Empirical management: no definitive diagnosis Intermittent twice daily use of mild, topical steroid cream combined with antifungal agent (clotrimazole with hydrocortisone). Appropriate use of emollients (trial of both water-based and paraffin-based depending on state of skin) In severe cases consider potent steroids such as dermovate and/or systemic antipruritic (non sedating cetirizine or sedating chlorpheniramine), sedating agents with nerve-modifying functions such as low dose amitriptyline 10-20mg nocte. (discuss such management with a senior clinician). Consider role of biopsy. PRURITUS ANI CEG SEPT 2015 Page 3 of 3 .