Related Experiment Video
Updated: Jun 1, 2026

Cheek Injection Model for Simultaneous Measurement of Pain and Itch-related Behaviors
Published on: September 27, 2019
Pruritus ani
1Department of Coloproctology, Seoul Song Do Colorectal Hospital, Seoul, Korea.
Abstract:
Pruritus ani is an unpleasant cutaneous sensation that induces the desire to scratch the skin around the anal orifice. It may start insidiously and appears in 1% to 5% of the population. It is classified as primary (idiopathic) pruritus ani when no cause can be found. However, as 25% to 75% of cases have co-existing pathology, a detailed history and examination are necessary. The goal of treatment is asymptomatic, intact, dry, clean perianal skin with reversal of morphological changes. The management of pruritus ani is directed towards the underlying cause. If the diagnosis is idiopathic pruritus ani, the patients can still be managed with great success by eliminating of irritants and scratching, by giving general advice regarding hygiene and lifestyle modification and by using active treatment measures.
Related Concept Videos
Assessment of the Rectum and Anus
Rectal Inspection
Begin by inspecting the perianal and anal areas for color, texture, rashes,...
Accessory Structures of the Skin: Hair and Hair Follicles
Hair is a keratinous filament growing out of the epidermis. It is primarily made of dead, keratinized cells. Hair strands originate at the epidermal penetration called the hair follicle. The hair shaft is the part...
The Micturition Reflex
The process begins with bladder filling, where the bladder wall stretches as urine accumulates. This stretching activates the urine storage reflex, mediated by the sacral spinal segments and the pontine storage center. Efferent sympathetic impulses stimulate the detrusor muscle to relax and the internal urethral sphincter to contract, facilitating urine...
Psychosexual Stages of Personality: Anal
Anatomy of the Genitourinary System II: Bladder and Urethra
Urethra
The anatomy of the urethra differs between males and females. In females, the urethra is short, measuring about 3โ4 cm in length, and opens anterior to the vaginal opening. In males, the urethra is longer and passes through the penis, serving dual purposes: expelling urine and ejaculating semen. The male urethra is...

