lichen simplex chronicus (LSC)

Introduction

Form of lichenification generally occurring in localized plaques.

Etiology

• repeated scratching
• emotional stress may be factor
  • skin is target of patient's anxiety
  • patients may have some insight into their disorder

Epidemiology

• adults > 20 years of age
• more frequent in women than men
• possibly higher incidence in Asians & native Americans

Pathology

• hyperplasia of all epidermal components
• acanthosis
• elongated & broadened rete ridges
• spongiosis uncommon
• chronic inflammatory infiltrate in dermis

Clinical manifestations

• solid plaques with minimal scaling & scarring
• distribution: (areas easily reached by dominant hand)
  • nuchal area
  • scalp
  • lower extremities, especially lower legs & ankles
  • anogenital region
    • case of vulvar pruritus without vaginal involvement
    • case with burning on urination
    • case with hyperpigmentation of labia majora & hypertrophy of labia minora
  • upper trunk
• lesions may last weeks to years
• pruritus often paroxysmal
• lichenified skin often becomes a pleasure to scratch
• scratching becomes reflexive & habitual
• itching may start from minor stimuli
• skin becomes warmer in bed often precipitating itching
• excoriations are frequently present
• in blacks lichenification may consist of multiple 2-3 mm papules rather than plaques
• generally dull red in color, later turning brown or black
• difficulty falling asleep

Laboratory

• KOH preparation of skin scraping to rule out dermatophytes
• wet mount of vaginal secretion to exclude vulvovaginal candidiasis
  • pH < 4.6

Differential diagnosis

• psoriasis vulgaris
• early stages of mycosis fungoides
• contact dermatitis
• dermatophytosis
• Schamberg's disease

Management

• occlusive bandages at night to prevent scratching & to facilitate penetration of topical steroids
  • cloth dressings
  • plastic dressing
    • hydrocolloid dressing
    • cordran tape (corticosteroids) impregnated in plastic tape
  • Unna boot
• glucocorticoids
  • topical glucocorticoids covered by continuous dry occlusive gauze dressing
  • intralesional triamcinolone (3 mg/mL)
  • 5% crude coal tar in zinc oxide paste plus corticosteroids with occlusive cloth dry dressing
• doxepin 5% ointment

More general terms

• neurodermatitis
• lichenification
• chronic skin disease

More specific terms

• vulvar lichen simplex chronicus; vulvar squamous cell hyperplasia; hyperplastic vulvar dystrophy