Lichen simplex chronicus

Published on 18/03/2015 by admin

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Last modified 18/03/2015

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Lichen simplex chronicus

Lacy L. Sommer, Christian R. Millett and Donald J. Baker

Evidence Levels:  A Double-blind study  B Clinical trial ≥ 20 subjects  C Clinical trial < 20 subjects  D Series ≥ 5 subjects  E Anecdotal case reports

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Lichen simplex chronicus (LSC, or neurodermatitis circumscripta) is characterized by pruritic, lichenified plaques that most often occur on the neck, anterior tibias, ankles, wrists, and anogenital region in response to chronic localized scratching or rubbing. Primary LSC evolves on apparently normal skin from pruritus of unclear etiology, whereas secondary LSC is superimposed upon pre-existing dermatoses, especially atopic dermatitis, psoriasis, or dermatophytosis. Psychogenic factors can play an important contributory role, and psychopathology has been found at higher rates in LSC groups as compared to control groups. Neurological abnormalities may sometimes be a factor in the etiology of LSC, as an association between long-standing LSC on the limbs and chronic cervical or lumbar radiculopathy has been reported.

Management strategy

The objective of treatment is to remove environmental trigger factors, break the itch–scratch cycle, and treat any underlying cutaneous or systemic disease. Patients’ understanding of their role in the itch–scratch cycle is essential if their cooperation in avoiding scratching is to be enlisted, thereby facilitating a more complete and permanent recovery. Recurrences are frequent and complete resolution often requires multiple approaches to therapy. Environmental trigger factors such as harsh skin care products or bathing regimens, friction, and excessive moisture or dryness should be minimized or eliminated. High-potency topical corticosteroids, such as clobetasol, diflorasone, and betamethasone, as creams or ointments, are the initial treatments of choice. The potency and/or frequency of application of topical corticosteroids should be decreased as the lesion resolves to avoid atrophy with their long-term use. Adjunctive therapies such as doxepin cream may be introduced if topical corticosteroids are not easily tapered. Occlusion has been found to be a successful aid to therapy because it provides a physical barrier to prevent scratching and permits enhanced and prolonged application of topical medications. Occlusive plastic film or hydrocolloid dressings have been used alone or over mid-potency corticosteroids. Flurandrenolide tape is very effective as both an occlusive and anti-inflammatory measure and is usually changed once daily, although a short occlusion-free period each day will help minimize the side effects of occlusion therapy. In chronic, difficult cases on the lower leg, an Unna boot (a gauze roll impregnated with zinc oxide) may be applied for up to 1 week, provided there is no concomitant infection of the occluded area. Calcineurin inhibitors such as tacrolimus and pimecrolimus also have been successfully used as monotherapy to treat LSC, and offer a good alternative for treatment in steroid sensitive areas such as the genitalia.

Intralesional injections of triamcinolone at monthly intervals can rapidly induce involution. Although highly effective, repeated injections may cause depigmentation or thinning of the epidermis. Therefore, other therapies should be used if several treatments with intralesional corticosteroids do not clear LSC. Infected areas should not be injected with corticosteroids because of the risk of abscess formation. Secondary infections should be treated with appropriate topical or systemic antibiotics. Intralesional botulinum toxin has been reported to offer lasting relief in patients with recalcitrant LSC.

A variety of other therapies have been reported to be effective in the management of LSC. Doxepin cream, capsaicin cream, or aspirin/dichloromethane solution are occasionally of value alone, but are probably best used as adjunctive therapy when LSC does not quickly clear with topical or intralesional corticosteroids. Oral antihistamines may be useful for their sedative effect on patients who scratch during their sleep. Cryosurgery and surgical excision have been reported to help some patients with nodular neurodermatitis. Non-invasive transcutaneous electrical nerve stimulation (TENS) has emerged as a possible effective treatment for pruritic dermatoses such as LSC. Pruritus and neuralgia of varying etiologies have responded to the anticonvulsant gabapentin, which may explain its usefulness in treating LSC. In more severe or recalcitrant conditions, psychotherapy and/or the use of psychopharmacologic agents may be needed for sustained improvement. Benzodiazepines, amitriptyline, pimozide, and doxepin have been used to treat neurotic excoriations and severe neurodermatitis. Neurodermatitis has improved with habit-reversal behavioral therapy, biofeedback, and hypnotherapy in certain individuals. Acupuncture and electroacupuncture are labor intensive, but have been effective in treating some cases of LSC.

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