6-34: Lichen Simplex Chronicus (Circumscribed Neurodermatitis)

ESSENTIALS OF DIAGNOSIS

GENERAL CONSIDERATIONS

Lichen simplex chronicus represents a self-perpetuating scratch-itch cycle that is hard to disrupt.

CLINICAL FINDINGS

Intermittent itching incites the patient to scratch the lesions and may interfere with sleep. Dry, hypertrophic, lichenified plaques appear on the neck, wrists, ankles, or perineum (Figure 6–21) (eFigure 6–66) (eFigure 6–67). The patches are rectangular, thickened, and hyperpigmented. The skin lines are exaggerated.

DIFFERENTIAL DIAGNOSIS

This disorder can be differentiated from plaque-like lesions such as psoriasis (redder lesions having whiter scales on the elbows, knees, and scalp and nail findings) (Figure 6–22), lichen planus (violaceous, usually smaller polygonal papules), and nummular (coin-shaped) dermatitis (eFigure 6–68). Lichen simplex chronicus may complicate chronic atopic dermatitis or scabetic infestation.

TREATMENT

For lesions in extragenital regions, ultra-high potency topical corticosteroids are effective, with or without occlusion, when used twice daily for several weeks (Table 6–2). In some patients, flurandrenolide (Cordran) tape may be effective, since it prevents scratching and rubbing of the lesion. The injection of triamcinolone acetonide suspension (5–10 mg/mL) into the lesions may occasionally be curative. Continuous occlusion with a flexible hydrocolloid dressing for 7 days at a time for 1–2 months may also be helpful. Dupilumab is a new treatment option for generalized disease or prurigo nodularis, its related condition. For genital lesions, see the section Pruritus Ani.

PROGNOSIS

The disease tends to remit during treatment but may recur or develop at another site.