Makindo Medical Notes

Pruritus ani is the medical term for itching around the anus. It is a symptom, not a diagnosis, and can be due to a wide variety of causes — local, systemic, dermatological, or idiopathic. The chronic "itch–scratch cycle" often perpetuates symptoms even when the initial trigger has resolved.

📍 Local Causes

• 🚻 Poor perianal hygiene (or conversely, overzealous cleaning causing irritation).
• 💦 Excessive sweating and moisture retention (common in warm weather or obesity).
• 🔧 Anal fistula with persistent discharge.
• 🔴 Haemorrhoids causing mucous seepage.
• 🧬 Anal or perianal neoplasia (rare but important to exclude).
• 🦠 Viral warts (HPV-related).
• 🍄 Fungal infections such as Candida albicans.
• 🧴 Contact dermatitis (to soaps, deodorants, wipes).
• 🪱 Worm infestations (especially Enterobius vermicularis in children).
• 💊 Antibiotics → diarrhoea or candida overgrowth.

🌍 General/Systemic Causes

• 🍬 Diabetes mellitus (secondary infections, candidiasis).
• 💛 Obstructive jaundice (bile salt deposition in skin).
• 🧪 Hodgkin’s lymphoma (generalised pruritus).

🩺 Dermatological Causes

• 🕷️ Scabies.
• 🪳 Pediculosis (pubic lice).
• 🧴 Psoriasis (may involve perianal area).
• 🌿 Atopic eczema or lichen sclerosus.

🔍 Symptoms and Signs

• 🌙 Nocturnal worsening of itch (classic, esp. in worm infestation).
• 📝 History of triggers — antibiotics, diabetes, jaundice, skin disease.
• 👀 Perianal skin: may be normal, erythematous, moist, excoriated, or thickened.
• 🤲 PR exam and proctoscopy essential to rule out haemorrhoids, fissures, or fistulae.

🧪 Investigations

• 📊 FBC (Hb) — chronic blood loss/anaemia.
• 🧪 Urine dip and blood sugar — screen for diabetes.
• 🔬 Perianal scrapings for fungal microscopy.
• 🪱 Cellophane tape test in children (for pinworm ova).
• 📸 Consider biopsy if suspicious lesion.

💊 Treatment

Management is twofold: treat the underlying cause and provide symptomatic relief.

• 🧼 Maintain meticulous but gentle hygiene — avoid excessive scrubbing.
• 🥗 High-fibre diet & adequate hydration — prevent constipation and straining.
• 🩲 Loose, breathable cotton underwear — avoid sweating and chafing.
• 🚿 Wash with plain water or mild soap after defecation; pat dry (not rub).
• 🌿 Apply soothing agents (glycerine, witch hazel, zinc oxide barrier cream).
• 💊 Topical 1% hydrocortisone or mild steroid + local anaesthetic for short-term relief.
• 🪱 Anthelmintics (e.g., mebendazole) if pinworms suspected.
• 🍄 Topical antifungal if candida infection confirmed.

⚠️ Prognosis & Pearls

💡 Clinical Pearls: - Always exclude sinister causes (anal carcinoma, HIV-related lesions) in persistent or refractory pruritus ani. - Nocturnal itch in children → think of Enterobius (threadworms). - Many cases remain idiopathic, and managing the itch–scratch cycle with behaviour modification is key. - In resistant cases, dermatology or colorectal referral may be needed.