A 5-year-old girl is brought to the office for evaluation of "itchy private parts" for the past week. Her mother has noticed the scratching at bedtime but not during the day. Due to the itching, the patient has difficulty falling asleep. Her mother has been applying a topical emollient with only minimal symptom relief. The patient has no urinary symptoms and has soft bowel movements once every other day. She attends daycare during the week and lives with her mother, stepfather, and 13-year-old stepbrother, none of whom have similar symptoms. Physical examination shows an erythematous vulva and no vaginal discharge. The perianal area is excoriated and diffusely erythematous. No other lesions are noted. Which of the following is the most likely diagnosis in this patient?

Question

A 5-year-old girl is brought to the office for evaluation of "itchy private parts" for the past week.  Her mother has noticed the scratching at bedtime but not during the day.  Due to the itching, the patient has difficulty falling asleep.  Her mother has been applying a topical emollient with only minimal symptom relief.  The patient has no urinary symptoms and has soft bowel movements once every other day.  She attends daycare during the week and lives with her mother, stepfather, and 13-year-old stepbrother, none of whom have similar symptoms.  Physical examination shows an erythematous vulva and no vaginal discharge.  The perianal area is excoriated and diffusely erythematous.  No other lesions are noted.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d6bd_7554_bc81_1dcd4ea0eeb5_MD0003_00 Pinworm (Enterobius vermicularis) is a common helminth infection in school-age children and typically presents with nocturnal perianal pruritus (pruritus ani). Transmission occurs via contact with contaminated objects (eg, bedding, clothing) or unwashed hands after scratching the perianal area. Although adult worms live in the intestines, females migrate distally to deposit eggs onto the perianal skin, primarily at night, causing symptoms. Mature pinworms can also spread to the vagina and cause vulvovaginitis, as seen in this child. Transmission Diagnosis is made via the "tape test," in which an adhesive is pressed on the perianal area (ideally in the morning or at night) and eggs and/or pinworms are visualized on the adherent material under microscopy. Treatment with albendazole or pyrantel pamoate is recommended for the patient and other individuals in the household to avoid reinfection. (Choice A) Candida vulvovaginitis presents with vaginal pruritus, erythema, and discharge, usually in the setting of recent antibiotic use. Vaginal candidiasis does not cause perianal abnormalities. Candida vulvovaginitis (Choice B) Contact dermatitis can manifest as nonspecific vulvovaginitis due to a topical irritant (eg, bubble bath, restrictive clothing). However, symptoms typically are present throughout the day, and perianal itching is not expected. (Choice D) Lichen sclerosus can cause perianal and vulvar pruritus as well as vaginal discharge or bleeding. Findings include hypopigmentation and ecchymoses of the affected area, not seen on this patient's examination. (Choice E) Neisseria gonorrhoeae cervicitis is a sexually transmitted infection that typically presents with vaginal discharge, not seen in this patient. (Choice F) Scabies is a mite infection that presents with intensely pruritic papules usually involving the interdigital web spaces, axillae, wrists, and genitalia. This patient's localized perianal and vulvar erythema is more consistent with a pinworm infection. Educational objective: Pinworm infection typically presents with nocturnal perianal pruritus and can cause vulvar and perianal erythema. Diagnosis is confirmed by visualization of eggs and/or pinworms on the "tape test." Treatment is with albendazole or pyrantel pamoate. References: Pruritis ani: diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/24280401) Vulvovaginitis in childhood. (http://www.ncbi.nlm.nih.gov/pubmed/19884044)

A 5-Year-Old Girl Is Brought to the Office for Evaluation