Anal itching

#### What you need to know A 39 year old lorry driver describes three months of an itchy bottom. He has tried to improve his hygiene and showers several times a day. It has now become embarrassing in public. He is otherwise well, his bowel habit is unchanged, and he has had no rectal bleeding and no history of bowel problems. Itching in the perianal area—pruritus ani—causes discomfort with an uncontrollable desire to scratch. Patients may be embarrassed to talk about it. Data on prevalence and aetiology are scarce because most patients do not consult a doctor.1 It is estimated that 5% of the population are affected by anal itching at some point in life, more commonly men, and predominantly when they are in the fourth to sixth decade of life.2 Itching may be short lived or chronic and can be caused by local factors or systemic disease (box 1). More commonly, it is idiopathic and no cause is identified.3 4 #### Box 1: Possible causes of pruritus ani (idiopathic if no cause is identified) ##### Colorectal