Anal itching

Anal itching is usually the consequence of mild conditions that resolve within a short time without complications.

Symptoms and causes

Anal itching, known in medical terms as anal pruritus, is a very common symptom among the general population. This itching sensation in the anus may occur constantly or intermittently and often becomes more intense at night or after defecation.

The prognosis is usually good, as it is rarely indicative of a serious problem. Even so, it can be very bothersome and negatively affect quality of life.

Symptoms

The main symptom of anal pruritus is itching, which may vary in intensity, but it does not usually occur on its own. It is often accompanied by the following signs:

Burning: a burning sensation in the perianal skin.
Redness and inflammation.
Irritation and tenderness to touch.
Feeling that the area is not completely dry.
Pain and discomfort.
Thickened skin: the texture of the skin may change due to scratching.
Mild bleeding.

Causes

The origin of anal itching can be very diverse. The most common causes include:

Irritation: the skin surrounding the anus is very sensitive, which increases the likelihood of chafing due to:
- Poor hygiene.
- Excessive cleansing with soaps that do not respect the skin’s pH or with toilet paper that is too rough.
- Moisture caused by sweating, inadequate drying or the use of tight underwear or synthetic materials.
Allergies: adverse reactions to toilet paper, creams, detergents or fabric softeners.
Perianal dermatitis: inflammation of the skin surrounding the anus.
Haemorrhoids: one of the most common causes. The veins of the anus become inflamed and form varicosities.
Anal fissure: small cracks form in the skin.
Anal fistula: an abnormal connection forms between the anal canal and the skin.
Candidiasis: a fungal infection that proliferates in warm, moist environments.
Parasites: the most common cause among children. Itching increases at night because this is when the worms lay their eggs around the margins of the anus.
Sexually transmitted infections (STIs): condylomas, or anal warts, caused by the human papillomavirus (HPV), may cause itching.
Unbalanced diet: excessive coffee, tea, cola drinks, alcohol, chocolate, citrus fruits, tomatoes or spicy foods may irritate the anus during defecation.
Stress and anxiety: skin conditions are common signs of these mental health disorders.
Anal cancer: although it is not a common symptom, anal pruritus may indicate the presence of a tumour if it is accompanied by bleeding, pain, changes in bowel habits or palpable lumps.

Risk factors

Factors that may increase the risk of developing or aggravating anal itching include:

Excessive moisture in the area, whether due to overweight, excessive sweating, intense physical activity or the use of inappropriate underwear.
Excessive or insufficient hygiene.
Chronic diarrhoea.
Faecal incontinence.
A diet with an excess of spicy foods, alcohol, citrus fruits or coffee.
Weakened immune system.
Diabetes.
Psoriasis.
Atopic dermatitis.
Sedentary lifestyle.

Complications

As a general rule, anal itching and the conditions that cause it do not lead to complications. Even so, they may result in:

Wounds or fissures caused by scratching.
Secondary bacterial infections, when lesions caused by scratching become infected.
Lichenification: hardening of the skin that causes chronic itching.
Insomnia: nocturnal itching may disrupt the sleep cycle.

Which doctor treats anal itching?

Anal pruritus is managed by the specialties of Family and community Gastroenterology, Medical-surgical dermatology and Venereology or Proctology.

Diagnosis

To determine the exact cause of the itching, the following tests are performed:

Medical history: a thorough clinical history is taken to determine the patient’s medical background, as well as hygiene habits and the characteristics of the itching.
Visual inspection: an examination to detect fissures, haemorrhoids, redness, thickened skin, scaling or any other abnormality.
Graham test: transparent adhesive tape is placed on the anal area in the morning to try to collect pinworm eggs.
Skin scraping or culture if bacterial or fungal infection is suspected.
Digital rectal examination: the tone of the anal sphincter is assessed and the presence of masses or internal abnormalities is ruled out.
Allergy testing if contact dermatitis caused by hygiene products is suspected.
Anoscopy or colonoscopy: in patients over 50 years of age, this test may be recommended to rule out serious conditions. To do this, a flexible tube with a camera at the end is inserted through the anus to observe the condition of the colon, rectum and anus. During this procedure, samples may be taken for subsequent analysis if malignancy is suspected.
Biopsy: a tissue sample is taken for laboratory analysis to determine the agent causing an infection or whether tumour markers are present.

Treatment

In most cases, anal itching is relieved with home remedies:

Adequate hygiene: clean the area with warm water and neutral soap after defecation and dry without rubbing, using gentle dabbing motions.
Keep the area dry: ensure that the anus is completely dry after cleaning. Cotton gauze may be used for this purpose, or unscented talcum powder may be applied.
Use loose-fitting cotton underwear to promote breathability.
Avoid scratching to prevent skin damage.
Follow a balanced diet: increase fibre and water intake to prevent constipation, and eliminate irritating foods such as coffee, alcohol, citrus fruits, spicy foods, tea and tomatoes.

If home care is not sufficient to relieve anal itching, the specialist may prescribe various treatments, such as:

Topical medication: depending on the causes of the pruritus, the following types of ointments are recommended:
- Barrier ointments, containing zinc oxide, to protect the skin.
- Corticosteroid ointments to reduce inflammation.
- Antifungal ointments to treat fungal infections.
- Antibiotic ointments to fight bacterial infections.
Oral antihistamines: these help control itching, especially nocturnal itching.
Haemorrhoids usually respond well to anti-inflammatory and decongestant creams. If discomfort persists, they may be removed by means of:
- Electrocoagulation: electrical current is applied to cut off the blood supply to small haemorrhoids.
- Sclerotherapy: sclerosing microfoam is injected to close the blood vessels supplying the haemorrhoids.
- Haemorrhoidectomy: large haemorrhoids are removed in a surgical procedure.
Mild fissures are treated with topical medication to promote healing and skin regeneration, relieve pain and reduce inflammation. When they are more severe, the following may be used:
- Botulinum toxin injections to relax the sphincter and allow a greater amount of blood to reach the area and, therefore, faster healing.
- Sphincterotomy: surgery to divide the internal lateral sphincter and reduce spasms.
STDs require antibiotic or antiviral treatments, depending on the type. HPV warts are usually removed with topical medications, laser surgery or cryotherapy.