Vulvar Inflammatory Dermatoses (also Refer CME Summary/Dev Approach)

Question 1

Lichen sclerosus

Answer 1

Predilection for anogenital skin
Prepubertal girls + post menopausal women
F > M

CLINICAL FEATURES
Symptoms
- Itch —> often severe and distressing
- Dyspareunia/discomfort if introital narrowing
- Constipation in prepubertal girls

Presentation -

• Flat atrophic white patches
• Figure of 8 configuration (extending around vulval and perianal skin)
• Oedema
• Purpura/ecchymosis
• Bullae
• Erosions
• Fissures
• Ulceration
• Can be hyperkeratotic

Signs of scarring -

• Loss of labia minora/fusion
• Buried clitoris
• Introital narrowing d/t anterior and posterior labial fusion
• milia

Sites - 
- Genitocrural folds
- Inner aspects labia majora
- Labia minora
- Clitoris
- Clitoral hood 
- Perianal (30% women, never men ? Urine causing barrier impairment in F)
Spares mucosal epithelium —> vestibular lesions and vaginal involvement does not occur

DDX
Vitiligo
Mucous membrane pemphigoid
LP
Morphoea

N.B. There can be clinical and histological overlap between LS, morphoea and LP —> may represent spectrum of disease rather than distinct conditions

EXTRAGENITAL LS (Skin)
Ivory white papules and plaques woth follicular delling
10% of F with vulval disease
Trunk, sites of pressure, upper back, wrist, buttock, thighs, facial, scalp, nail

ASSOCIATED DISEASES —> other autoimmune disorders
Thyroid disease (mainly F > M)
Pernicious anaemia
Type 1 DM
Coeliac disease
RA
Psoriasis

Co-existent Vitiligo
Co-existent Alopecia areata
Co-existent morphoea
Co-existent oral lichen planus

PREDISPOSING FACTORS
Koebner phenomenon
- sometimes seen in episiotomy scars
- RTX sites
- Scar tissue
- Vaccination
- Congenital haemangioma

Positive fam Hx

PATHOGENESIS
Aetiology unknown
Autoimmune predisposition

IX
Bx before starting Rx (essential in atypical disease, lack of Rx response, comfirm Dx) - definitely do this in adults d/t higher risk of VIN
- for children, clinical dx sufficient if dx clear —> neoplastic transformation never been reported in this cohort

TFT, thyroid ABs (assoc autoimmune thyroid disease)
ANA
Other autoimmune tests as guided by hx and exam

HISTO
Thinned epidermis
If epidermis thickened —> squamous cell hyperplasia —> 30% found in assoc with vulvar SCC
Flattening of rete ridges
Underlying dermis hyalinised
Below hyalinised dermis —> band-like zone of chronic inflammatory cells
Absent elastic fibres
Extravasated RBC (clinical petechiae/purpura/ecchymosis)

GENERAL MEASURES
Stop irritants
Soap substitute (emulsifying ointment)
If eroded, urinary incontinence —> zinc sudocrem barrier cream
If menopaused —> topical oestradiol (vagifem) to reduce symptoms of atrophic vagina
Ensure PAP smear UTD ? Risk of VIN
Stop smoking

MX —> refer to CME summary

COURSE/PROGNOSIS
Good response to superpotent TCS
Relapse
? Prepubertal LS remits at puberty

COMPLICATIONS
Scarring (irreversible)
VIN/Vulval SCC (oncogenic HPV subtypes not implicated) —> persistent fissures, non-healing ulcers, hyperkeratotic plaques, nodules
Verrucous CA
BCC
Melanoma