Vulvovaginal and common prepubertal gynaecological disorders: SAQ

This girl has a specific Group A streptococcal vulvovaginitis, which is the commonest identifiable pathogen in prepubertal vulvovaginitis and is treated with a targeted oral antibiotic. The presence of a recognised respiratory and skin pathogen rather than a sexually transmitted organism should reassure the mother on the question of sexual transmission, although the clinician must always assess the broader context and be alert to any red flags. ^{[3] [4]}

Question 1 (10 marks)

Classify vulvovaginitis in the prepubertal girl, explain the pathophysiology that predisposes to it, and outline the management of this child. ^[1]

Vulvovaginitis is classified as nonspecific when no pathogen is identified on culture and specific when an organism is cultured. The nonspecific, or irritant, form accounts for 50 to 75 percent of cases and reflects the vulnerability of the prepubertal vulval mucosa to poor hygiene, tight clothing, and faecal contamination. ^[1] The specific form is caused by an identifiable organism, most commonly Group A beta-haemolytic Streptococcus, but also Haemophilus influenzae, Shigella, and Streptococcus pneumoniae. Candida is rare in the healthy prepubertal girl because the neutral vaginal pH does not favour its growth. ^[3]

The predisposing pathophysiology is the hypo-oestrogenic state of the prepubertal vulva. The vulval epithelium is thin, the vaginal pH is neutral between 6 and 8 rather than the acidic 3.8 to 4.5 of the adult, and the lactobacilli that dominate the adult vaginal flora are absent. ^[1] The thin, unprotected mucosa is easily irritated by contact with urine, faeces, soap, and tight clothing, and the neutral pH allows organisms such as Group A Streptococcus to proliferate. The anatomical proximity of the anus and the vagina in the young child and the imperfect wiping technique at the developmental stage of two to four years drive the recurrent cycle of contamination and inflammation. ^[4]

The management of this child combines a targeted antibiotic with hygiene education. The Group A Streptococcus is treated with a 10-day course of oral penicillin or amoxicillin, and the response is usually rapid. ^[4] The family is advised on perineal hygiene: washing with plain water or a mild non-soap cleanser, avoiding bubble baths and scented products, dressing the child in loose cotton underwear, teaching front-to-back wiping, and avoiding tight-fitting clothing. A follow-up review confirms the resolution of the discharge and the erythema. ^[1]