Vulvovaginal and common prepubertal gynaecological disorders: Viva

Branch 1: Confirming the diagnosis

The candidate should recognise the presentation as classic paediatric lichen sclerosus, a chronic inflammatory dermatosis of unknown cause that presents with intense pruritus, soreness, and the characteristic porcelain-white, atrophic, wrinkled plaques in the figure-of-eight distribution around the vulva and the anus. [8] The small purpuric spots are typical of the active disease, in which the fragile sclerotic skin bruises and tears with minimal trauma. The diagnosis is clinical in the great majority of cases and rests on the recognition of this distribution and this appearance. [10]

If the examiner presses on the differential diagnosis, the candidate must distinguish lichen sclerosus from vulval vitiligo, which is depigmented but not atrophic or pruritic, from atopic or contact dermatitis, which is erythematous and itchy but lacks the porcelain-white sclerosis, and from the bruising and scarring of sexual abuse. [10] A skin biopsy confirming the epidermal atrophy, the basement membrane thickening, the upper dermal collagen homogenisation, and the band of lymphocytic inflammation is reserved for cases where the diagnosis is uncertain or the condition does not respond to an appropriate course of treatment. [9]

Branch 2: The management and the rationale

If asked about management, the candidate should state that the first-line treatment is an ultra-potent topical corticosteroid, as established by the NASPAG clinical recommendation. [8] The standard regimen is clobetasol propionate 0.05% ointment applied to the affected skin once daily for 4 to 8 weeks for the induction of remission, followed by a tapering maintenance regimen of once or twice weekly application. [11] The family is counselled that the condition is chronic and relapsing and that long-term follow-up is essential. [9]

A strong candidate explains the rationale for using an ultra-potent rather than a weak steroid, because the under-treatment of lichen sclerosus with a mild topical agent allows the sclerosis and scarring to progress. [11] The family may be anxious about applying a potent steroid to the vulval skin of a child, and the candidate should explain that the short-term induction regimen is safe when supervised and that the maintenance regimen minimises the total steroid exposure while preventing relapse. The long-term outlook is that a proportion of girls have persistent disease into adulthood, so the family is prepared for the possibility of ongoing management rather than the expectation of complete resolution at puberty. [9]

Branch 3: Changing the scenario

If the examiner changes the scenario to include bruising and behavioural concerns, the candidate must address the question of coexisting sexual abuse. The skin changes of lichen sclerosus, with their purpura, fissures, and scarring, can mimic the signs of abuse, and the two conditions can coexist. [8] The key message is that lichen sclerosus is not caused by sexual abuse, but that its presence does not exclude coexisting abuse, and the two diagnoses require separate and parallel assessments. [9]

The candidate should outline the child protection assessment, which includes a detailed history, a full examination to document the distribution and the nature of the findings, and, when the history or the findings are inconsistent with the explanation offered, a referral to the child protection team for a formal evaluation. [8] The dermatological treatment of the lichen sclerosus is delivered alongside the safeguarding plan, and the two pathways proceed in parallel. The candidate should stress that a confident diagnosis of lichen sclerosus on clinical and histological grounds should reassure the clinician and the family about the skin changes, while the safeguarding assessment addresses the broader concerns independently. [10]

If the examiner changes the scenario to a persistent or bloody vaginal discharge instead of the pruritic plaques, the candidate should shift to the foreign-body pathway and state that the discharge warrants vaginoscopy under anaesthesia to find and remove a retained object such as toilet paper. [10]