Pruritus Ani (Anal Itching)

PHYSIOLOGY OF PRURITUS ANI:

Anal itching or pruritus ani has many causes but the most common cause of itching is unknown or idiopathic (idiopathic pruritus ani). Men are affected four times more than women. Most people believe that itching is due to hemorrhoids and with hemorrhoid surgery the itching should improve. This is only true when the hemorrhoids are prolapsing (protrude from the anus) which causes an irritation from the fluid secreted from the anal mucosa. If a patient has prolapsing hemorrhoids with discomfort, bleeding and itching, surgically correcting the hemorrhoids will resolve the itching. When a patient has idiopathic anal pruritus with mildly enlarged or normal sized hemorrhoids, hemorrhoid surgery will not alleviate the symptoms. Other causes of itching include; fungal and yeast infections, pinworm (parasite) infections, wiping with poison oak or poison ivy, psoriasis, STD’s (syphilis, herpes, warts, etc.), precancerous lesions and anal cancer.

Idiopathic pruritus ani is multifactorial and therefore there is no cure. Factors associated with itching include; stool consistency, coffee (including decaffeinated blends), chocolate, citrus fruits, tomatoes or tomato based products, poor hygiene, trauma from wiping and scratching, hemorrhoid mucous secretion, directly applying soap to the anus, and long term steroid use. Studies have shown a direct correlation between the amount of coffee consumed and the severity of the itching. It is also well known that scratching is euphoric and gives a strong sense of relief. It is surmised that there is a component of addiction to scratching and therefore even if the itching completely resolves, sometime in the future it will most likely return.

Itching can be mild or severe. The itching is usually worse at night. Typically over time the itching worsens. The process is cyclical and hard to break. The itching leads to scratching or excessive, aggressive, wiping which leads to abrasions and inflammation. The acute trauma to the skin leads to anal burning. As the wounds heal, Histamine is released. Histamine causes itching of the skin. When a patient scratches aggressively multiple micro cuts and abrasions develop which cause the severe burning. In a day or so the burning resolves and the itching improves. In the next few days as the multiple wounds heal the Histamine release causes a sharp rebound itching that is worse than before. This leads to aggressive scratching, causing more damage thus continuing the cycle of itching and scratching.

TREATMENT OF ITCHING

• Dietary Measures
  • Fiber is a complex carbohydrate, which binds with water in the colon creating larger, solid, stool.
    • What I have found over the years is that the majority of patients with idiopathic itching have soft sticky stools which require a lot of wiping, or even showering, after a bowel movement to get clean. Remember, the more trauma to the anus the more itching. Wiping a lot worsens the trauma. Furthermore, sticky stools, like peanut butter or toothpaste, are hard to clean. Toothpaste is a perfect example. The toothpaste tube is similar to the rectum, it is the reservoir that holds the toothpaste. The neck of the toothpaste tube with the threads is just like the anus. Once you squeeze the toothpaste onto the toothbrush, the toothpaste is now in the neck of the toothpaste tube. If you put the tube on the counter, without the cap, in the morning you will find toothpaste on the counter. If you try to clean the neck there is still a lot of sticky toothpaste in the tube to leak out. This is exactly the same as the anus. With a lot of sticky stool in the anus no matter how hard one tries to clean the anal canal it is too long to clean completely and the remaining sticky stool within the rectum eventually seeps out of the anus which coats the skin causing irritation and itching.
    • The best way to combat this problem is to solidify the stool to the consistency of Play Dough. We have all used Play Dough. It is solid but soft and does not stick like toothpaste. If you were to put Play Dough into a toothpaste tube and squeeze it all out you would not find Play Dough on the counter in the morning. If your stool has Play Dough consistency, after a complete evacuation, the whole volume of stool is removed with nothing left in the rectal vault and anus. Wiping should be minimal. Also, there will be nothing to seep out later. This is the “no wiper” bowel movement we all strive for. You know, the one that gives you a sigh of content and the urge to smoke a cigarette when you are done. Let me be clear, you do not eat Play Dough to have these types of bowel movements. Fiber is what is necessary to change the stool consistency.
    • Personally, the bulking agent I recommend the most is Konsyl. It contains 6 grams of psyllium fiber, more than any other product. I use Konsyl every morning. When shaken (not stirred) with about 4-5 oz. of juice it goes down smooth (no I do not own stock in the company). It is important to drink enough water during the day in order for the fiber to work. Eating fiber without enough water can lead to constipation. It is recommended to eat 30-35 grams of fiber per day. The average daily American diet contains only 6-10 grams of fiber! It is also wise to eat foods lower in fat and cholesterol.
  • Water is very important as it is soaked up by the fiber making the stools bulky and soft. Water is a natural lubricant and is important for good bowel regularity. At least four 8 ounce glasses are necessary per day. Caffeine and liquor are diuretics which increase urination causing dehydration. Stool becomes harder as the colon is used to reabsorb more water during times of dehydration. Therefore, coffee, tea, caffeinated sodas, and liquor do not count as water. Drinking water with each meal will add 3 glasses of water a day.
  • Caffeine is strongly associated with idiopathic anal itching. The more caffeine the more severe the itching. I suggest cutting coffee out of the diet. I don’t suggest quitting coffee cold turkey but to do it slowly. Chocolate also contains a lot of caffeine so those patients who eat a lot of chocolate will need to remove chocolate from the diet.
  • Tomatoes and Citrus are associated with itching. It is thought the acidity of the tomatoes, tomato based products and citrus irritates the anal skin worsening the symptoms. If you eat a lot of these types of foods you should cut back.
• Avoiding Irritants
  • Avoid soap to directly cleanse the anus. Most patients feel that the anus is not clean without washing with soap. Soap is a drying agent and when applied directly to the anus causes irritation and cracking of the skin. Only a washcloth and water are needed to cleanse the anus. Remember, the oral cavity has many more harmful and aggressive bacteria than the anus and we don’t brush our teeth with soap. Also avoid Witch Hazel as it is an astringent which dries the skin worsening the itching.
  • Baby wipes should be used to wipe the anus. Alcohol free, unscented baby wipes are not traumatic to the anus. Toilet paper is made of wood pulp so even though it is soft it causes micro cuts when wiping, especially when wiping aggressively to scratch. Baby wipes are made of cotton and will not cause trauma to the anus. Fragrances and alcohol are irritants and dry the skin
• Topical Treatments
  • Steroid ointment is very effective in controlling itching. Steroids decrease the inflammatory response which stops the release of Histamine. I prefer Analpram 2.5% as it has an anti itch medication called Pramoxine which is mixed with a powerful steroid. This combination is like crack cocaine to those with anal itching. It works so well patients can become dependent on the medication. Long term use of steroids causes thinning of the skin which leads to excoriation and abrasions. This leads to itching and the need to use more steroids. I recommend using Analpram 2.5% twice a day for 2 weeks and then discontinuing the medication.
  • Calmoseptine ointment is a non steroid ointment that can be used as much as necessary. It is comprised of Calamine lotion and Zinc oxide. The Zinc oxide coats the skin protecting it from irritants and the Calamine lotion sooths the itching.
  • Balneol rectal lotion is another non steroid ointment which cleanses and sooths the anal skin. It is also free of astringents or alcohol and is safe to use for long periods of time.
  • Preparation-H: A topical ointment which sooths the outside of the anus. Though it is believed that Preparation-H will shrink the tissue, there is no scientific evidence (that I am aware of) proving this phenomenon. I believe it is the soothing nature of the ointment that helps the symptoms. It is a benign ointment so if it works there is no problem with continuing its use.
  • Spectazole 1% ointment is used for patients with fungal infections of the perianal skin.
• Office based treatments
  • Hemorrhoid therapy helps to reduce the itching by decreasing the amount of mucous secreted from the hemorrhoids. Large inflamed hemorrhoids secrete mucous which mixes with the sticky stool allowing the stool to leak from the anus and coat the skin. Shrinking the hemorrhoids stops the mucous discharge. A substance (phenol mixed with olive oil) is injected into the internal hemorrhoids causing them to shrink. This procedure is done in the office and is painless!!

CONCLUSION

Anal itching is usually idiopathic which means there is no known cause of the symptoms. The problem is multifactorial and therefore is typically not curable unless a cause such as a yeast infection, sexually transmitted disease, pre-cancer, or cancer is identified. Multiple treatments are available and changing one’s diet and cleansing habits are very helpful. Stool consistency is associated with itching so adding fiber to solidify the stool is very important. It is surmised that there is a component of addiction to scratching and therefore even if the itching completely resolves, sometime in the future it will most likely return.

Though the problem is primarily benign, cancer is associated with anal itching so it is strongly recommended to see a proctologist for an evaluation.

Dr. David Rosenfeld is a board certified colorectal surgeon and proctologist (bum Doctor) – 805-230-BUTZ (2889)