What are the causes of pruritus ani (anal itching)?

From the Guidelines

Pruritus ani, or anal itching, is commonly caused by poor hygiene, moisture, dietary factors, skin conditions, infections, and certain medications, as supported by the most recent study 1.

Causes of Pruritus Ani

The causes of pruritus ani can be multifactorial, including:

• Poor hygiene, which can leave irritating fecal residue
• Moisture from sweating or incomplete drying, creating an environment for irritation and infection
• Dietary triggers, such as spicy foods, caffeine, alcohol, citrus, and tomatoes
• Skin conditions, like psoriasis, eczema, and contact dermatitis, which frequently affect the anal region
• Infections, including fungal infections (candidiasis), parasitic infections (pinworms), and sexually transmitted infections
• Certain medications, particularly antibiotics that disrupt normal bacterial balance

Diagnosis and Treatment

Diagnosis of pruritus ani involves a thorough medical history and physical examination, including a digital rectal examination 1. Treatment should address the underlying cause, which may include:

• Improved hygiene practices, such as gentle cleaning with water and thorough drying
• Dietary modifications to avoid triggers
• Antifungal creams for fungal infections
• Antiparasitic medications for pinworms
• Topical steroids for inflammatory skin conditions
• Wearing loose cotton underwear and avoiding prolonged sitting to reduce moisture and irritation in the area

Importance of Accurate Diagnosis

It is essential to accurately diagnose the cause of pruritus ani to provide effective treatment and prevent complications, as highlighted in the study 1. A thorough evaluation, including laboratory and radiological studies, may be necessary to rule out underlying conditions, such as anorectal abscess or fistula 1.

From the Research

Primary Causes of Pruritus Ani

• Fecal soiling 2
• Food irritants 2

Secondary Causes of Pruritus Ani

• Malignancy 2, 3
• Infections, including sexually transmitted diseases 2
• Benign anorectal diseases, such as:
  • Hemorrhoids 2, 3, 4
  • Anal fissures 2, 3, 4
• Systemic diseases 2
• Inflammatory conditions 2
• Neoplasia, including:
  • Rectal cancer 3
  • Anal cancer 3
  • Adenomatous polyps 3
  • Colon cancer 3

Other Factors Associated with Pruritus Ani

• Coffee intake 3
• Smoking 3
• Alcohol consumption 3
• Abnormal proctosigmoidoscopy or colonoscopy findings 3
• Local irritants, such as household chemicals 5