Pruritis ani

Pruritus ani is the medical name given to the sensation of a persistent itch that affects the skin around the anus. It is a symptom, not a disease. Patients with severe pruritis can develop a nearly uncontrollable desire to scratch. Excessive rubbing or scratching of the skin results in damage, which can lead to more serious problems with superinfection and long-term changes to the anal skin. Troublesome pruritus ani is thought to affect 1%-5% of the adult population and appears to be more prevalent in men than women.

 

Causes

Pruritus ani can be secondary to other systemic diseases, associated with a poor anal hygiene regimen, overaggressive cleansing, and use of ointments/lotions that cause local irritation; however, in more than one half of patients with pruritus ani the cause is idiopathic spontaneous (without direct cause).

 

Investigation

A detailed history and careful physical examination with inspection and anorectal examination is helpful; skin scrapings to exclude fungal and yeast infection may be necessary and skin biopsy may be useful in suspicious skin lesions. In patients with young children, nocturnal pruritis may be a sign of threadworm infection. Sometimes, flexible sigmoidoscopy or colonoscopy may be required.

 

Treatment

Treatment is almost always nonsurgical. The goal for therapy is to:

• Treat underlying causes such as haemorrhoids.
• Exclude or treat threadworm.
• Avoid irritants such as alkaline soaps or perfumed cleaning products.
• Improve perianal hygiene and avoid scratching.
• Achieve a soft comfortable, non-irritant stool. This can be accomplished by adjusting the diet to increase the amount of daily fibre [aim for 25 to 30g per day] or by adding a fibre supplement, and avoiding foodstuffs that cause irritant faeces such as coffee, tea, caffeinated fizzy drinks, beer, chocolate, and tomatoes. The key, though, is to ensure that the patient increases the amount of water he or she drinks to about 2 litres per day in the average adult.
• Hydrocortisone ointment (0.5 to 1.0% solution) can provide symptomatic relief, but cannot be used for prolonged periods of time because this can cause skin damage.
• Skin barrier creams or ointments can also provide relief.
• Patients with symptoms resistant to the usual treatments may be referred to a dermatologist.