lichen simplex chronicus

(redirected from Atypical nodular form of neurodermatitis circumscripta)
Also found in: Dictionary, Wikipedia.
Related to Atypical nodular form of neurodermatitis circumscripta: Nodular prurigo, prurigo nodularis, pickers nodule

Lichen Simplex Chronicus

 

Definition

Lichen simplex chronicus is a chronic inflammation of the skin (dermatitis) characterized by small, round itchy spots that thicken and become leathery as a result of scratching.

Description

Also termed neurodermatis, lichen simplex chronicus is the result of chronic skin irritation. It occurs in 4-5 out of every thousand people. Initial irritation causes itching, and in turn, itching causes scratching. Scratching leads to further irritation, which damages the skin. The possibility of infection is greatly increased when the outer layer of protective skin is broken. Skin usually repairs itself quickly; however, in the case of lichen simplex chronicus, healing skin causes more itching and more scratching causes a thickening of the skin (lichen). The small skin patches are usually 1-10 in (2.54-25.4 cm) in diameter.

Causes and symptoms

Lichen simplex chronicus is often caused by constant rubbing of the skin. The rubbing begins the chain of events that leads from itching to scratching and then to the presence of leather-like skin patches.
Symptoms are chronic itching which is often accompanied by nervous tension. The appearance of scratch marks and the leathery skin patches can be found anywhere on the body. A prolonged lichen simplex chronicus can result in brown-colored pigmentation at the site of irritation.

Diagnosis

A dermatologist, a physician specializing in the study and treatment of skin disorders, can make a diagnosis after a visual exam.

Treatment

Treatment of the itching is necessary to stop the scratching and resulting skin damage. There are a number of ways to stop itching. Perhaps the most important is to cut fingernails very short. Ice can substitute for the relief of scratching. Heat and fuzzy clothing worsen itching; cold and smooth clothing pacify it. If the itching is persistent, dressings may be applied to the affected areas.
Among the topical medications that relieve itching are a number of commercial preparations containing menthol, camphor, eucalyptus oil, and aloe. Topical cortisone is also available without a prescription. Some preparations also contain antihistamines, which penetrate intact skin poorly. All these medicines work better under occlusion, which means putting a waterproof barrier like a rubber glove or plastic wrap over them. For broken skin, topical antibiotics like bacitracin help prevent infection. These should be used early to forestall further damage to the skin.
Reducing the buildup of thick skin may require medicines that dissolve or melt keratin, the major chemical in skin's outer layer. These keratolytics include urea, lactic acid, and salicylic acid.
Resistant cases of lichen simplex chronicus will often respond to cortisone-like drugs injected directly into the lesions.
Sedatives or tranquilizers may be prescribed to combat the nervous tension and anxiety that often accompanies the condition.

Prognosis

Diligent adherence to treatment is usually rewarded with a resolution of the condition. The original cause of itching may be gone, or it may reappear. Preventive treatment in its early stages will arrest the process.

Prevention

Early, gentler substitutes for scratching can entirely prevent lichen simplex chronicus.

Key terms

Antihistamine — A chemical that interferes with the action of histamine. Histamine is part of an inflammatory response and helps to cause itching.
Callus — Thickened skin due to chronic rubbing or irritation.
Lesion — Abnormal change in tissue caused by localized disease.

Resources

Books

Swerlick, Robert A., and Thomas J. Lawley. "Eczema, Psoriasis, Cutaneous Infections, Acne, and Other Common Skin Disorders." In Harrison's Principles of Internal Medicine, edited by Anthony S. Fauci, et al. New York: McGraw-Hill, 1997.

lichen

 [li´ken]
1. any of certain plants formed by the mutualistic combination of an alga and a fungus.
2. any of various papular skin diseases in which the lesions are typically small, firm papules set very close together.
lichen amyloido´sus a condition characterized by localized cutaneous amyloidosis.
lichen fibromucinoido´sus (lichen myxedemato´sus) a condition resembling myxedema but unassociated with hypothyroidism, marked by mucinosis and a widespread eruption of asymptomatic, soft, pale red or yellowish, discrete papules.
lichen ni´tidus a usually asymptomatic chronic inflammatory eruption consisting of numerous glistening, flat-topped, discrete, smooth, commonly skin-colored micropapules, located most often on the penis, lower abdomen, inner thighs, flexor aspects of the wrists and forearms, breasts, and buttocks. Widespread involvement may produce confluence of the lesions, with formation of scaly plaques.
lichen pila´ris lichen spinulosus.
lichen planopila´ris a variant of lichen planus characterized by formation of cone-shaped horny papules around the hair follicles, in addition to the typical lesions of ordinary lichen planus.
lichen pla´nus an inflammatory skin disease with wide, flat, purplish, shiny papules in circumscribed patches; it may involve the hair follicles, nails, and buccal mucosa; called also lichen ruber planus.
lichen ru´ber monilifor´mis a generalized or localized eruption with either round, dome-shaped, waxy, dark or bright red papules, or waxy, yellow, milia-like papules, often forming a moniliform (string-of-beads) pattern, sometimes arranged in keloidal bands. Some authorities consider the condition to be a variant of lichen simplex chronicus.
lichen ru´ber pla´nus lichen planus.
lichen sclero´sus (lichen sclero´sus et atro´phicus) a chronic atrophic skin disease marked by white papules with an erythematous halo and keratotic plugging. It sometimes affects the vulva (kraurosis vulvae) or penis (balanitis xerotica obliterans).
lichen scrofuloso´rum (lichen scrofulo´sus) a form of tuberculid manifested as an eruption of clusters of lichenoid papules on the trunk of children with tuberculous disease.
lichen sim´plex chro´nicus dermatosis of psychogenic origin, marked by a pruritic discrete, or more often, confluent lichenoid papular eruption, usually confined to a localized area. Mechanical trauma, such as scratching or rubbing the area, is a factor in its development. The lesions may arise from normal skin or they may occur as a complication of other forms of dermatitis. Called also circumscribed or localized neurodermatitis and lichen chronicum simplex.

Treatment consists of administration of corticosteroids applied locally as a cream or given by intralesional injection to relieve the pruritus. The area should be protected by light dressings and the patient encouraged to avoid mental stress, emotional upsets, and irritation of the affected area. The application of very hot or very cold compresses may afford temporary relief of the itching. The condition tends to become chronic with unexplained remissions and reappearance of lesions in a different part of the body.
lichen spinulo´sus a condition in which there is a horn or spine in the center of each hair follicle; called also lichen pilaris.
lichen stria´tus a self-limited condition characterized by a linear lichenoid eruption, usually in children.
lichen urtica´tus papular urticaria.

li·chen sim·plex chronicus

a thickened area of itching skin resulting from rubbing and scratching.

lichen simplex chronicus

a form of dermatitis characterized by a patch of pruritic confluent papules. Factors such as scratching contribute to its chronicity. Treatment may include topical or intralesional application of corticosteroids to relieve the pruritus.
enlarge picture
Lichen simplex chronicus

lichen simplex chronicus

A dermopathy characterised by intensely pruritic nodules on the arms or legs, often with excoriations due to itching.

Aetiology
Idiopathic; it may be associated with Becker's nevus, linear IgA disease, and liver disease, and triggered by internal malignancy, liver or renal failure.

DiffDx
Systemic pruritus—cholestasis, thyroid disease, polycythaemia rubra vera, uraemia, Hodgkin lymphoma, HIV and other immune deficiencies; delusions of parasitosis and other psychiatric conditions.

lichen simplex chronicus

Dermatology A type of atopic dermatitis characterized by chronic pruritus, resulting in thick leathery hyperpigmented skin, exacerbated by emotional stress and associated with psoriasis, anxiety, depression, and mental retardation. See Atopic dermatitis.
Enlarge picture
LICHEN SIMPLEX CHRONICUS

lichen simplex chronicus

An itching papular eruption that is circumscribed and located on skin that has become thickened and pigmented as a result of scratching. Synonym: circumscribed neurodermatitis See: neurodermatitis for illus.
illustration
See also: lichen
Full browser ?