PERIANAL AREA: CHARACTERISTICS AND DISEASES - SCIENCE - 2024

The perianal area or perineum is the area of ​​soft tissue that covers the muscles and ligaments of the pelvic floor between the vagina and the anus in women and between the scrotum and the anus in men.

The perineum is the region between the lower thighs and the pelvic diaphragm. The limits of this region are the same as for the pubic symphysis, the ischiopubic rami, the sacrotuberous ligaments, and the coccyx.

The perineum has a roof formed by the pelvic diaphragm and a floor of fascia and skin. It also contains the muscles and neurovasculature associated with the urogenital structures and the anus.

The perineal or perianal area is the narrowest region between the proximal parts of the thighs and when the lower limbs are abducted it is a diamond-shaped area that extends forward from the mons pubis, the medial surfaces within the thighs and gluteal folds and the upper end of the gluteal cleft.

There are two ways to describe the limits of the perineum. Anatomical borders refer to your exact bony margins. The superficial borders describe the superficial anatomy that marks the borders of the perineum.

Anatomical borders of the perineum

• Anterior symphysis - pubic.
• Posterior- The tip of the coccyx.
• Laterally - Lower pubic branch and lower ischial branch, and the sacrotuberous ligament.
• Ceiling - The pelvic floor.
• Base - Skin and fascia.

The perineum can be subdivided by a theoretical line drawn transversely between the ischial tuberosities. This division forms the anterior urogenital and posterior anal triangles. These triangles are associated with different components of the perineum.

Borders of the surface of the perineum

For clinical purposes, it is important to know the superficial anatomy that marks the limits of the perineum. These limits are best shown when the lower limbs are abducted, and a diamond shape is represented.

The limits of the skin of the perineum:

• Previously: Mount of Venus in females and base of the penis in males.
• Laterally: Medial surfaces of the thighs.
• Posterior: Upper end of the gluteal cleft.

Pain in the perianal area

Pain in the perianal area occurs adjacent to the anus. Pain or discomfort is usually in the area between the anus and vagina in women, and between the anus and scrotum or penis in men.

Perianal pain is frequently caused by gastrointestinal problems such as anal fissures, hemorrhoids, etc. Perineal pain can vary in severity. Perineal pain can be severe or feel like only mild perineal discomfort.

Common causes of chronic perineal pain in men include prostatitis / pelvic pain syndrome and urinary tract obstruction in men. Perineal pain in women is often related to interstitial cystitis syndrome and pelvic pain in women. It can also be caused by neuropathic pain

Causes of perianal pain in men

-Prostatitis

-Prostatic stones

-Benign prostatic hypertrophy (enlarged prostate)

-Obstruction of the ejaculatory duct

-Urinary dysfunction

-Pelvic floor dysfunction

-Neuropathic pain

-Musculoskeletal or referred pain

Causes of perianal pain in women

-Vulvodynia

-Urinary tract infections

-Neuropathic pain

-Musculoskeletal or referred pain

-Pelvic floor dysfunction

-Urinary tract dysfunction

Common causes in men and women

-Pain syndromes such as urethral syndrome, perineal pain syndrome.

-Interstitial cystitis.

-Anal fissures.

-Pudendo nerve entrapment syndrome.

-Ischiorectal abscess.

Perineal descent

Perineal descent is a condition in which the perineum prolapses (bulges down) or descends below the bony outlet of the pelvis. Perineal descent is often associated with chronic exertion in patients with chronic constipation.

Other conditions that weaken the pelvic floor muscles can also lead to symptomatic perineal descent. An amount of perineal descent is often present in conjunction with pelvic organ prolapse.

Treatment begins with the identification and treatment of the underlying cause. As mentioned above, constipation and the need for chronic deformation is often identified and treated. Pelvic floor physical therapy to strengthen the pelvic floor can sometimes be used to better help symptoms.

If surgery is performed, the focus is on elevation of the perineum and pelvic floor with a Da Vinci sacrocollopoperineopexy or posterior vaginal mesh placement with perineorrhaphy and elevation of the perineum. The choice of surgery depends on the presence of other conditions such as uterine prolapse.

Skin of the perianal area

The skin of the perianal area is very sensitive and is susceptible to injury and damage from diarrhea and constipation. Irritation of the perianal area can occur with persistent diarrhea.

Diarrhea itself can be caustic and burn the skin, and repeated wiping with toilet paper can cause further trauma. Treating the diarrhea and then keeping the area clean and dry are important in healing the perianal skin.

Diseases and conditions of the perianal area

Diseases and conditions that can affect the perianal skin include:

External hemorrhoids

Hemorrhoids that occur on the outside of the anus can be painful, itchy, and tend to bleed. Hemorrhoids can occur due to liver disease, constipation, diarrhea, or during pregnancy.

Symptoms may be worse during a bowel movement. In many cases, hemorrhoids improve with home treatment, but in some cases they may need to be treated by a gastroenterologist or colorectal surgeon. If a blood clot occurs, the hemorrhoid can become thrombosed and cause more pain and swelling.

Crohn's disease

Crohn's disease can occur in any part of the digestive system, and the perianal area can also be affected. About 24% of patients with Crohn's disease have disease in the perianal area.

People with Crohn's disease can also have skin tags, hemorrhoids, or, in extremely rare cases, cancer in the perianal area. In many cases, a colorectal surgeon will need to be consulted in the care of patients presenting with complications from Crohn's disease.

Perianal abscess

An abscess is a collection of blood and pus that can occur anywhere in the body, including the perianal area. People with inflammatory bowel disease, and especially those with Crohn's disease, are at higher risk of developing a perianal abscess.

A perianal abscess can start after a tear in the anus, and some bacteria enter the body through that tear. The symptoms of a perianal abscess are swelling, pain, fever, and loss of bowel control. Abscesses in the perianal area are usually treated by draining them, followed by antibiotics.

Perianal fistula

The fistula is the tunnel that forms under the skin and connects the clogged infected glands to an abscess. A fistula can be present with or without an abscess and can connect only to the skin of the buttocks near the anal opening.

A possible complication of a perianal abscess, generates the development of a fistula in the area, a fistula that can sometimes become chronic. A fistula could also form after trauma or as a complication of Crohn's disease, anal fissures, cancer, radiation therapy, actinomycosis, tuberculosis, or chlamydial infection.

Symptoms include a break in the skin, swelling, pain, and drainage (from pus or stool) from the area. Treatment may be with surgery (fistulotomy) or the placement of a seton through the fistula.

References

1. Tresca, A. (2016). What Is The Perianal Area?. 11-1-2017, from verywell.com Website: verywell.com.
2. Buckmire, M. (2015). Abscess and Fistula Expanded Information. 11-1-2017, from DCR Journal Website: fascrs.org.
3. Fidoe, S. (2016). The Perineum Boundaries. 11-1-2017, from The TeachMe Series Website: teachmeanatomy.info.
4. Shasoua, G. (2014). Perineal descent. 11-1-2017, Austin Urogynecology Website: teachmeanatomy.info.
5. Shteynshlyuger, A. (2013). Treatment of Perineal Pain. 11-1-2017, from New York Urology Specialists Website: newyorkurologyspecialists.com.