A 2-year-old girl is brought to the office by her mother, who noticed an abnormality in the genital area while changing her diaper. The patient has had multiple diaper rashes over the last 6 months but has had regular bowel movements and no dysuria or hematuria. She has no chronic medical conditions and no known allergies. Vital signs are normal. On pelvic examination, the labia minora appear thin, are fused together at the midline, and partially block the urethral meatus. Multiple excoriations are seen, but there is no rash or perianal involvement. No vaginal discharge is seen at the introitus. Internal pelvic examination is deferred. Which of the following is the most likely diagnosis in this patient?
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This patient has thin, fused labia minora due to labial adhesions. This condition is most commonly seen in prepubertal girls due to low estrogen production. Inflammation from poor hygiene, infection (eg, vaginitis), irritation (eg, diaper rash), or trauma (eg, straddle injury) also contributes to the development of adhesions.
Labial adhesions can be partial (involving a portion of the labia) or complete. Partial adhesions, as seen in this patient, are often asymptomatic; however, some individuals may experience vaginal pain or pulling. Adhesions covering the urethral meatus can also cause an abnormal urinary stream and an increased risk for recurrent urinary tract infections due to urine accumulation.
Although mild, asymptomatic adhesions require no treatment, topical estrogen is first-line therapy for those with symptoms.
(Choice A) Candida vulvovaginitis presents with a beefy-red rash on the vulva as well as vaginal pruritis and discharge. Although patients with repeated yeast infections are more prone to labial adhesions, it is unlikely in this patient with no rash or vaginal discharge.
(Choices B and D) Contact dermatitis and lichen sclerosus are types of skin inflammation that can predispose to labial adhesions. However, contact dermatitis presents with a pruritic, erythematous rash, and lichen sclerosus is characterized by hypopigmented labial lesions. This patient has no skin discoloration on examination.
(Choice E) Pinworm infection typically presents in school-age children with perianal itching, particularly at night. Although pinworms can cause vulvovaginitis in some cases, labial fusion is not associated.
(Choice F) Urethral prolapse presents in prepubertal girls with inflamed, friable tissue in a donut shape at the urethral meatus. This patient's obstructive, fused labia is due to labial adhesions.
Educational objective:
Labial adhesions, or fused labia minora, are most commonly seen in prepubertal girls with low estrogen production. Partial adhesions are typically asymptomatic, and no treatment is necessary. Topical estrogen is first-line therapy for symptomatic lesions.