In this article, we will discuss the common causes of anal itching, medical treatments, and home remedies.
Here are some key points about pruritus ani. More detail and supporting information is in the main article.
- Anal itching may be embarrassing - but it is a common problem seen by doctors
- Too much or too little cleansing can lead to itchiness around the anus
- Some foods and drinks are associated with pruritus ani
- Skin conditions, infections, anorectal disorders, whole-body medical conditions, and drugs are all potential causes
What is anal itching?
Scratching an itchy bottom can make the problem worse.
Pruritus ani is the medical term for anal itching or itchy bottom. It is defined as intense itching around the anus. Other terms include:
- Anal pruritus
- Perianal itching
- Anorectal itching
- Itchy butt/bum/bottom
The anus is the opening at the end of the gut or digestive system, allowing us to expel solid waste from the body. Pruritus ani refers to itching around the anus.
Anal itching is a symptom, not a disease in itself; it is a surprisingly common problem, which many people are too embarrassed to see their doctor about.
Pruritus ani can happen to anyone but is said to be more common in men than women and more common in adults than children or the elderly.
What can begin as a brief irritation can soon become a chronic problem as the scratch-itch cycle continues. Scratching causes tiny little breaks in the skin that are intensely itchy when the usual moisture and humidity of the perianal area comes into contact with them. This causes more scratching and further tiny itchy cuts.
This scratch-itch cycle is made worse by nighttime scratching when the sufferer is half asleep and unaware that they are scratching, especially as loose nightclothes allow easier access.
When urine passes over the cuts in women, it causes stinging, which is then relieved by over-vigorous wiping with toilet paper, again further damaging the skin.
Often the condition can be cured by a strict no-scratching period, which allows the skin to heal and breaks the cycle. However, a physician should examine the skin and lower bowel to make sure there are no medical problems.
Causes of anal itching
Pruritus ani can have a primary or secondary cause:
- Primary cause - the itching is not the result of another condition
- Secondary cause - the itching has an underlying condition that causes the itching
The list of secondary causes can be collected into broad groups:
- Hygiene - too much or too little
- Skin irritants - such as soaps
- Skin conditions - such as dermatitis and psoriasis
- Anal or rectal disorders - piles, and anal fistulas and fissures, for example
- Infections - including parasitic and sexually transmitted
- Systemic (entire body) medical conditions - including aplastic anemia, diabetes, inflammatory bowel disease, jaundice, leukemia, lymphoma, and thyroid disease
- Foods - dietary irritants, such as chilli peppers
- Drugs - including chemotherapy, colchicine, neomycin, and quinidine
Some foods may make the itching worse, so identifying and avoiding these may help. Examples include:
- Spicy foods
- Citrus fruits, such as oranges
- Dairy products
- Excessive liquids, such as milk, beer, or wine
Often, no cause is identified for the itching - in these instances, the pruritus is labeled idiopathic.
Dermatological (skin) causes
- Prolonged contact with feces can cause irritation.
- People who have fecal incontinence (little or no control over bowel movements) can have leakage, which can cause irritation and itching.
- Persistent diarrhea can cause irritation by nature of the frequency or bowel opening and wiping clean.
- Eczema and idiopathic dermatitis can affect the anal area. This is inflamed skin of no known cause.
- Keloid scar of skin - these are hard, smooth growths that develop when scar tissue develops excessively.
- Scabies - a skin infection.
- Allergic dermatitis may be due to allergic reactions to creams, lotions, bubble baths, washing powders, wet wipes, etc. Sometimes, creams that are used to soothe or treat the itch cause a worsening of the problem because of the chemicals they contain.
- Yeasts (thrush, candida), bacteria (beta hemolytic streptococci, staph aureus) and viruses such as the genital wart virus (HPV) can cause skin infections in the anal region.
- Pinworm is a very common cause of itchy bottom in children and families with young children. Female pinworms lay eggs in the folds of the anus; this can cause itching.
- Hookworm infection - these are parasites that can affect the lungs and small intestine.
- Small skin tags - may hide fecal residue or trap moisture, causing itching.
- Some sexually transmitted infections can cause itching in the region.
- Psoriasis is a chronic skin condition; it can also affect the perianal area.
- Proctitis - the inner lining of the rectum becomes inflamed.
Gastroenterological (bowel) causes
- Hemorrhoids (piles) can cause local irritation
- Anal cancer should always be considered and checked for
- Inflammatory bowel disease can cause frequent diarrhea and irritation
Systemic (whole body) causes
- Liver disease
- Thyroid problems
- Blood cancers
- Rheumatological diseases
- Autoimmune diseases
Psychological (mind) causesDiagnosis
The first time someone presents the problem of anal itching to their doctor, the consultation will start with a number of questions. This will help to see if the itching is due to local skin problems, or a more general problem with the whole body.
The doctor may:
- Ask about the duration and pattern of the itch
- Explore dietary intake and hygiene practices to see if there is inadequate or excessive washing, or use of creams, perfumes, or soaps
- Evaluate how severe the itch is, and work out its impact on life
Other information will help to pin down a possible cause for the pruritus ani:
- Is there a relevant past medical history, such as anorectal surgery, hemorrhoids, or diabetes?
- Has there been any urinary or fecal incontinence?
- Is there blood on toilet paper, anal pain, or lumps to indicate hemorrhoids?
- Has there been any bloody diarrhea and abdominal cramps (suggesting inflammatory bowel disease)?
A physical examination may follow so that the doctor can see how the problem looks, checking for signs of skin cracking or inflammation and any bleeding around the anal area. Chronic scratching can cause thickened pale skin.
A visual check may also reveal hemorrhoids, anal fissures, or eczema, for example. It may simply reveal soiling as the issue. The anus and rectum should also be examined for evidence of cancers.
An internal examination will be performed by the doctor - by inserting a gloved and lubricated finger through the anus into the rectum.
The doctor may ask you to clench your bottom, as a test of the anal sphincter, or ask you to push, as a way of looking for internal hemorrhoids that get pushed through to the outside (prolapse).
The whole body should be checked for other conditions that may have pruritus ani as a cause. Investigations for pruritus ani include:
- Swabs if infection is suspected
- A biopsy if there is any abnormal skin
- Stool cultures if there is any diarrhea
- Routine blood tests to check blood count, renal, liver, thyroid, diabetes, and inflammatory markers
Below are some practical tips to help with the treatment and prevention of an itchy bottom:
Home remedies and self-care
- Avoid highly seasoned and spiced foods, and maintain a regular bowel habit
- Keep the anal area clean after emptying the bowel
- Avoid medicated, perfumed, or deodorant soaps - use only plain warm water for cleaning, aqueous cream, or emollients
- Use moist toilet tissues instead of paper
- Avoid allowing the anal area to stay moist, and dry it gently by dabbing, not by rubbing
- Use drying powders, but not medicated or scented ones
- Avoid scratching the area, which creates further trauma and makes the problem worse
- Wearing socks or cotton gloves on the hands may reduce the harm from unconscious scratching for people who find they have been unable to resist overnight scratching
- Wear loose, breathable clothing, avoiding materials such as acrylic and nylon, which trap sweat
Understanding and educating about the scratch-itch cycle is very important. The skin must be allowed to heal to reduce the irritation that causes the scratching. Avoiding irritating soaps and creams, and keeping the skin cool, dry, and clean is essential.
Fingernails should be kept short, and intense itching soothed with cool water on cotton wool balls.
- Antihistamines - if itching is particularly troublesome during the night, doctors may offer an antihistamine such as hydroxyzine (Vistaril).
- Soothing ointments - bismuth subgallate or zinc oxide, for example - are prescribed for some skin problems.
- Corticosteroids - inflammation of the perianal skin may receive short-term topical drug treatment in the form of a mild corticosteroid - hydrocortisone, for example. However, some research has shown that, as an initial treatment step, cleansing can be as effective as corticosteroids.
- Local anesthetics - these can temporarily relieve pain and itching; they include benzocaine, benzyl alcohol, lidocaine, and pramoxine.
- Vasoconstrictors - these constrict blood vessels and can reduce swelling. They also act as mild anesthetics. These include ephedrine sulfate and epinephrine.
- Astringents - these chemicals promote protein aggregation within cells, which dries out the skin and helps reduce itching, burning, and pain.
- Protectants - these form a physical barrier between the skin and any potential irritants. They include aluminum hydroxide gel, cocoa butter, and glycerin.
- Keratolytics - these cause outer layers of tissue to disintegrate, allowing any medical ointments to penetrate deeper layers.
Other potential treatments:
- Capsaicin cream - the effectiveness of this treatment requires further study
- Anal tattooing - this has been trialed but, again, needs further evaluation before it can be recommended
- Hypnosis - the benefits of hypnosis to reduce scratching should also be further evaluated
If there is no underlying cause, the outlook is good. Once the skin has healed following the "no scratching rule," patients can expect a full recovery.