Itching of the anus is a common problem that we all experience every now and then. However, for some people it is a daily occurrence and can be intense and persistent to the point that it affects life. Scratching the buttocks or anus is not considered to be a socially acceptable act particularly in public which further adds to th distress.
Why does the anus itch?
The itching sensation is a type of defensive mechanism that alerts a person to the presence of a potentially harmful substance on the surface of the skin. The urge to itch is elicited through the stimulation of itch receptors (technically known as mechanoreceptors) in the skin, that get stimulated by the presence of an irritant on the surface of the skin.
The nerve impulse generated by the itch receptors travels to the central nervous system, where a feedback itching response is generated. Tickling and pain sensations may also be associated with the itching sensation. In some cases, itching may occur even in the absence of an irritant on the surface of the skin.
An itching sensation is limited to the surface of the skin, and does not occur in any internal tissue or organ. This is because internal tissues and organs lack the itch receptors that trigger the itching sensation. Pain receptors are also present on the surface of the skin as well as deeper lying tissue.
The skin around the anus has itch receptors, which can lead to anal itching (technically known as pruritis ani). At times, the anal itch may feel as if it is emanating from deep within the anal canal or rectum. However, it is important to note that the rectum does not have any itch receptors. Therefore, all anal itching sensations are caused by the itch receptors that lie in the skin around the anus (technically referred to as the perianal region).
Read more on itchy anus.
Causes of Anal Itching
The skin around the anus is thinner and more delicate than the skin in other parts of the body. Therefore, it is prone to injury and inflammation. Anal itching may sometimes be due to bowel disorders but most cases of anal itching are due to some abnormal condition of the skin in the perianal region, and are unrelated to the health of the bowels. Anal itching may sometimes be accompanied by pain or a burning sensation in the anus.
Often, no cause can be identified for most cases of short-lived anal itching. Such conditions with no identifiable cause are medically referred to as idiopathic. Almost every person experiences such short-lived instances of anal itching, which quickly subside on their own. Scratching the anal itch may at times worsen the condition by causing further damage and irritation in the skin.
Lack of hygiene
Since defecation occurs through the anus, the perianal region is prone to getting dirty with fecal matter and intestinal bacteria. If attention is not paid to maintaining proper anal hygiene through regular and proper cleaning of the area, accumulation of feces, sweat and bacteria can cause skin irritation and itching in this region. Bacterial infection of the skin in the perianal region is also facilitated by the moist and warm environment in the region between the buttocks.
It is noteworthy that anal itching may also be due to excessive cleaning of the perianal region. Excessive scrubbing of the region can cause damage to the delicate skin in the perianal area, leading to skin irritation and itching. Use of harsh soaps and detergents could also cause skin irritation and itching in the perianal region. Therefore, it is important to maintain proper anal hygeine without subjecting the anal area to overzealous treatments.
A variety of medical conditions that affect the anus and the rectum could cause anal itching. A common anorectal condition associated with anal itching is hemorrhoids or piles. Hemorrhoids refer to an abnormal distention of the veins in the rectum, making them visible as swollen lumps.
Hemorrhoids are associated with different conditions such as diarrhea, constipation, excessive straining during defecation, pregnancy and obesity. When hemorrhoids are large and external, the process of cleaning the anorectal area after defecation may cause irritation and itching in this region. Apart from hemorrhoids, fistulas, anal fissures, and criptitis may also be associated with anal itching.
Both infectious and non-infectious skin conditions affecting the perianal region can cause anal itching. Examples of non-infectious skin conditions associated with anal itching include psoriasis, atopic dermatitis, skin tags, warts and skin cancer. Scabies is an infectious condition that can cause anal itching.
Infection of the perianal skin or the bowels frequently result in anal itching. Some common infections that can lead to anal itching include bacterial skin infections, parasitic worms in the intestine, fungal skin infections (especially due to the yeast Candida albicans), and sexually transmitted diseases that result from anal intercourse.
A variety of chemicals such as scented soaps, antibacterial soaps, latex, lubricants, sanitary wipes and local anesthetics can cause irritation of the skin in the perianal region, leading to anal itching.
Anal itching may also result from the intake of certain foods. Immune-mediated hypersensitivity is one reason why certain foods may cause anal itching. In other cases, the exact reason may not be known. Examples of foods that are potentially associated with anal itching include nuts, dairy products, coffee, pepper, chocolate, and tomatoes. These foods do not affect everyone in the same manner. The trigger foods vary on an individual basis.
Anal itching may also be associated with the intake of certain drugs. Diarrhea and other side-effects of the drugs may be underlying cause. In some cases, the cause may not be known. Antibiotics are a class of drugs that can cause anal itching.
Treatment for Anal Itching
The exact treatment for anal itching depends on the exact cause of the problem. The following are some of the treatments that may be prescribed by the doctor:
- For anal itching caused by an allergic reaction, antihistamines may be given.
- For anal itching caused by a chronic inflammatory condition, corticosteroids may be the treatment of choice.
- Infectious causes of anal itching need to be treated with antimicrobial agents.
- Probiotics may be prescribed in cases of diarrhea or frequent bowel movements.
Read more on itchy bottom.
Apart from the medications, certain conservative measures may also be taken to treat anal itching. Maintaining proper anal hygiene is usually the primary focus. Vigorously scratching or rubbing the perianal region should be avoided since it may worsen the itch. If anal itching is found to be associated with certain foods, then those trigger foods should be avoided. Tight undergarments should not be worn. In some cases, anal itching may go away on its own, and no treatment measures need to be considered.