Lichen Simplex Chronicus

General information

Chronic inflammatory skin disorder characterized by localized lichenification caused by repeated scratching or rubbing.
Typically presents as one or more well-demarcated, thickened plaques.
Results from a self-perpetuating itch → scratch → inflammation → increased itch cycle.
Chronic mechanical trauma causes epidermal hyperplasia and skin thickening.
May develop on previously normal skin or secondary to an underlying pruritic dermatosis.
Atopic dermatitis or an atopic background may be associated.

Chronic, intense pruritus is the predominant symptom.
Itching may be intermittent or paroxysmal and is sometimes worse at night or during periods of inactivity.
Repeated scratching or rubbing may eventually become habitual or unconscious.
Scratching provides temporary relief but perpetuates the itch–scratch cycle.
Assess for underlying causes of pruritus, including atopic dermatitis, contact dermatitis, xerosis, and dermatophytosis.

Thickened, indurated, lichenified plaque, usually well demarcated.
Prominent accentuation of normal skin markings = characteristic finding.
Dry, rough ± scaly surface.
Excoriations and crusting may occur from scratching.
Brown, gray, or violaceous hyperpigmentation may occur.
Scaling is usually mild.
In darker skin tones, lesions may show prominent hyperpigmentation ± follicular papules.

Prominent skin markings and furrows.
Variable white scaling.
Areas of brown or gray pigmentation.
Excoriations, erosions, and crusts may be visible.
No pathognomonic dermoscopic pattern; dermoscopy is mainly helpful in evaluating alternative diagnoses.

Primarily a clinical diagnosis based on chronic pruritus, repeated scratching, and characteristic lichenification.
Evaluate for an underlying cause of pruritus.
KOH preparation/fungal culture if dermatophytosis is suspected.
Patch testing if allergic contact dermatitis is suspected.
Skin biopsy may be considered for atypical or persistent lesions or when the diagnosis is uncertain.
Histology typically demonstrates hyperkeratosis, acanthosis/epidermal hyperplasia, and superficial chronic dermal inflammation.

Primary goal: break the itch–scratch cycle.
Identify and treat any underlying pruritic skin disorder.
Minimize scratching and rubbing; occlusive dressings may help protect selected lesions.
Regular emollients to restore the skin barrier.
Potent to superpotent topical corticosteroids for appropriately located thick plaques.
E.g., clobetasol propionate 0.05% once or twice daily for 1–2 weeks, followed by reassessment.
For sensitive or thin-skinned areas, consider a lower-potency corticosteroid or topical calcineurin inhibitor, depending on location.
Refractory thick plaques: intralesional triamcinolone may be considered by a dermatologist; concentration and volume depend on lesion size and location.
A sedating antihistamine, such as hydroxyzine, may occasionally be considered short-term when nocturnal pruritus significantly interferes with sleep, with attention to adverse effects.
Address behavioral or psychological factors when they contribute to repetitive scratching.