What is pruritus ani (anal itching)?
pruritus ani is a dermatological condition characterized by itching in the anal area. The itching may become worse at night or after a bowel movement. Scratching the area results in further irritation and makes the itching worse instead of relieving it. Scratching with the fingernails may result in skin damage or an infection. If the itch-scratch cycle persists, it can lead to extreme discomfort, soreness, and burning.
What are the types of pruritus ani?
There are two main types of pruritus ani—primary and secondary.
- Primary (idiopathic) pruritus ani—This condition has no identifiable underlying cause. This is the most common type of pruritus ani.
- Secondary pruritus ani—This condition may be due to many different underlying causes. They may include infections, contact dermatitis or other dermatological conditions, systemic diseases, and other factors.
How common is pruritus ani?
It is estimated that 1-5% of the population is affected. Pruritus ani is about 4 times more likely to occur in men than in women. Primary or idiopathic pruritus ani accounts for the majority (about 50-90%) of cases.
What can cause dryness and irritation in the anal area?
The anal area may become dry and irritated due to the use of harsh soaps, sanitary wipes, or rough toilet paper to clean the area after a bowel movement. A hypersensitivity reaction may occur if perfumed powders, lotions, creams, ointments, or other products are applied in the anal region. Excess perspiration or small amounts of fecal matter can cause irritation and itching.
What causes pruritus ani (anal itching)?
Pruritus ani is usually not caused by poor hygiene. Rather, the overuse of soaps and other topical products to clean the anal region or vigorous scrubbing with a washcloth or rough toilet paper can cause irritation. A hypersensitivity reaction may occur if perfumed powders, lotions, creams, ointments, or other products are applied in the anal region.
Excess perspiration or moisture may become trapped in the anal area if constricting or tight-fitting underwear is worn. Some foods and beverages, such as carbonated drinks, caffeinated beverages (coffee, tea, colas) and spicy or acidic foods (tomatoes, citrus fruits) have been linked to the condition. Having frequent bowel movements (diarrhea) or infrequent ones (constipation) may also play a role.
Other causes of pruritus ani include:
- Infections: Some types of bacteria, fungi (yeast), or parasites can cause itching. Staphylococcus aureus or Streptococcus pyogenes (types of bacteria), Candida albicans (a yeast), pinworms (mainly in children), and Sarcoptes scabiei (scabies mites) are some organisms that result in itching and irritation.
- Dermatological conditions: Psoriasis, contact dermatitis (inflammation due to allergens or other irritants), or atopic dermatitis (a chronic condition found in patients with allergies) may cause a rash in the perianal region.
- Inflammatory bowel disease (Crohn’s disease)
- Psychological factors such as stress or anxiety
- Systemic diseases: These include diabetes mellitus, leukemia, lymphoma, thyroid disease, renal disease, and liver disorders (obstructive jaundice).
- Colorectal and anal disorders: Rectal prolapse, internal or external hemorrhoids, anal fissures (ulcers), or fistulas (abnormal tube-like passages) are associated with pruritus ani. Residual amounts of feces may be difficult to remove with large external hemorrhoids. Internal hemorrhoids may cause bleeding, fecal soiling, or drainage.
- Systemic or topical medications: Use of drugs such as quinine, colchicine, and mineral oil has been linked to pruritus ani.
- Fecal or urinary incontinence: Children and the elderly are more likely to experience incontinence of the bowel or bladder.