**2.4 Anorectal diseases**

Pruritus ani is commonly found in patients with numerous benign anorectal conditions, such as external and internal hemorrhoids (**Figure 3**), anal fissures and fistulas (**Figure 4**), hidradenitis suppurativa, perianal Crohn's disease, anal skin tags, and pilonidal disease. Symptoms can be caused by the disease itself, as well as from local skin irritation associated with fecal soiling, prolapsing tissue, mucus discharge, chronic drainage, etc. Perianal diseases commonly interfere with local hygiene, leading to skin irritation from residual fecal material. Management of the perianal condition is necessary and may improve symptoms, as it has been seen in patients with prolapsing hemorrhoids after hemorrhoidectomy [10]. One of the most common situations we encounter in our clinic are patients confusing pruritus ani with symptomatic hemorrhoids, driving many to self-medicate and worsen symptoms.

Malignant anorectal processes can also provoke pruritus ani and should be considered and ruled out when appropriate. Among these, diseases are anal canal

**Figure 3.** *Prolapse internal hemorrhoids. Courtesy of Arcila E, MD. Chicago, IL.*

**Figure 4.** *Anorectal fistula with perianal dermatitis due to chronic drainage. Courtesy of Young D, MD. Chicago, IL.*

**Figure 5.** *Squamous cell carcinoma of the anal margin.*

and anal margin cancer (**Figure 5**), low rectal cancer, Bowen's disease, or perianal squamous cell carcinoma *in situ* (**Figure 6**), and Paget's disease or cutaneous adenocarcinoma *in situ*. In patients with premalignant perianal lesions, such as anal intraepithelial neoplasia (AIN) caused by human papillomavirus infection (HPV), pruritus ani can be caused by the anal condyloma itself rather than the presence of dysplasia. The most common extra-mammary area affected by Paget's disease is the perianal region, occurring more frequently in white women in the sixth decade of life. In these cases, further evaluation of the gastrointestinal, urinary, and *Perspective Chapter: Management of Pruritus Ani DOI: http://dx.doi.org/10.5772/intechopen.102782*

#### **Figure 6.** *Bowen's disease.*

gynecologic systems is warranted, attributable to the high incidence of associated malignancy (33–86%) [11, 12].
