Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + • Severe perianal itching, often at night• When chronic, skin becomes white, leathery, and thickened• Usually idiopathic• Most patients have tried many over-the-counter preparations without relief• Agents may exacerbate the problem by keeping the perineum moist, causing further irritation, or by creating a contact dermatitis• Poor cleansing of the perineum may lead to irritation• Frequent washing with soaps and detergents dries the skin, also leading to pruritus• Pinworms (Enterobius vermicularis) are the most common cause of perianal itching in children• Pruritus may result from tight clothing, obesity, and living in a hot climate• When a specific cause cannot be found, it is considered idiopathic +++ Epidemiology + • Pinworms (E vermicularis) are the most common cause of perianal itching in children under 12 years of age• Enterobius (pinworm) is an intestinal roundworm (nematode) transmitted by ingestion of eggs• Adult male and female worms live in the colon -At night the female migrates from the anus and releases thousands of fertilized eggs on the perianal skin-Eggs develop into larvae and become infectious• Reinfection occurs if eggs are carried into the mouth after scratching the perianal skin +++ Symptoms and Signs + • Severe perianal itching, often worse at night• Skin is thickened, white, and leathery in the chronic state• Skin is normal to weeping in the acute stage• In children with pinworms, perianal itching is most severe at night when the pinworm deposits its eggs on the perianal skin +++ Laboratory Findings + • Scotch tape test: Diagnosis of pinworms is made by applying cellophane tape to the perianal skin, which collects the eggs• Scrapings of the perianal skin viewed microscopically may reveal fungi or parasites + • Associated with other perianal lesions that distort normal anal anatomy such as hemorrhoids, fistulas, fissures, tumors of the anorectum, previous surgery, and radiation therapy• Primary dermatologic diseases: -Lichen planus-Atopic eczema-Psoriasis-Seborrheic dermatitis• Infectious etiology:-Fungal (dermatophytosis, candidiasis)-Parasitic (E vermicularis, scabies, or pediculosis)-Bacterial superinfection• Contact dermatitis from local anesthetic creams or soaps• Systemic diseases (diabetes, liver disease)• Perianal neoplasms (Bowen disease and extramammary Paget disease) +++ Rule Out + • Perianal neoplasms (Bowen disease and extramammary Paget disease) + • History and physical exam• Biopsy and histologic evaluation may be necessary in refractory cases to rule out underlying malignancy• Scotch tape test + • Treat identifiable causes of pruritus ani (infection, hemorrhoids, contact dermatitis)• Patients should be educated about proper perineal care, and the use of soaps and topical ointments should be discouraged• The perineum should be kept dry• Alteration in dietary habits may be necessary -Coffee, tea, cola drinks, beer, chocolate, and tomatoes can cause perianal itching and should be excluded from the diet for at ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.