Lichen Simplex Chronicus (Neurodermatitis; Prurigo)
Are You Confident of the Diagnosis?
What to be alert for in the history
When obtaining a history, be alert for the following features:
-Chronic intractable itching, which triggers intermittent vigorous rubbing or scratching
-Pruritus that may be worsened with local heat or sweating or other irritant factors
-Preceding conditions may exist, such as allergic contact dermatitis or atopic dermatitis
-Stress may initiate or worsen the itch-scratch cycle
-Nighttime scratching occurs, resulting in sleep disturbance
-Classic locations: Ankle, back of neck, scalp, groin (scrotum)
Characteristic findings on physical examination
-Favors easily accessible sites such as nape of neck, scalp, extensor forearms, lower legs and anogenital areas (
-Presents as circumscribed lichenified plaques, often with peripheral lichenoid papules
-Variable erythema and hyperpigmentation are common
Expected results of diagnostic studies
Histopathologic examination demonstrates hyperkeratosis, patchy parakeratosis, hypergranulosis, and acanthosis (
Biopsy and histopathologic examination can distinguish the following conditions:
-Lichen amyloidosis: confluent keratotic hyperpigmented papules often presenting in a rippled pattern; anterior lower legs are the most common site
-Lichen planus: violaceous polygonal papules/post-inflammatory hyperpigmentation; volar wrists, lower back, ankles, genitalia are commonly involved; reticulate or ulcerative oral lesions and/or nail changes may be present
-Psoriasis vulgaris: often symmetric; erythematous circumscribed plaques with silvery white scale; favors scalp/extensor surface of extremities, sacrum; itching variably present
Who is at Risk for Developing this Disease?
Adult females are most commonly affected, peak incidence at ages 30 to 50 years. Risk factors include stress, a history of atopic dermatitis, allergic contact dermatitis, or xerosis. Up to one third of patients seen at a vulvar disorder clinic may be diagnosed with LSC.
What is the Cause of the Disease?
These chronic lichenified fixed plaques are the end result of the itch-scratch cycle. Plaques of LSC can occur de novo on normal skin, or may develop secondarily on pre-existing dermatologic conditions such as atopic dermatitis, allergic contact dermatitis, cutaneous fungal infections, psoriasis and others.
Underlying pathophysiology is not completely understood but is thought to result from an interplay of emotional stress, pruritus (environmental factors such as heat/sweat/mechanical irritants that stimulate sensory nerve endings) and subsequent rubbing or scratching that results in lichenification.
Systemic Implications and Complications
Psychogenic factors may be present, including anxiety, depression, or obsessive-compulsive disorder; consider a psychiatric referral in the appropriate clinical setting.
Systemic disease underlying the pruritus should be considered in selected cases; based on history and physical examination, consider laboratory evaluation for chronic renal disease, liver disease, lymphoma, thyroid disease, or hematologic conditions. Screening laboratory tests can include a complete blood count (CBC), comprehensive metabolic panel, thyroid function, sedimentation rate, serum protein electrophoresis and CXR.
Underlying dermatologic conditions may be present and require clinical and/or laboratory diagnosis, as follows:
-Atopic dermatitis (family history of atopy; personal history of early age of onset, xerosis, pruritus, typical distribution, chronicity)
-Allergic contact dermatitis (Patch testing may be indicated; North American Contact Dermatitis Group identified at least one positive relevant reaction in 63% of 347 patients with strictly anogenital dermatitis; the most common allergens included fragrance, preservatives, medications, vehicles, corticosteroids, metal and rubber)
-Psoriasis vulgaris (typical distribution; skin biopsy if necessary)
-Corticosteroids - with or without occlusion; in addition to topical application, intralesional steroids also an option
-Antipruritics (topical doxepin, capsaicin, pramoxine, oatmeal based moisturizers, 1% menthol and phenol in base creams)
-Immunomodulatory agents (tacrolimus ointment, pimecrolimus cream)
-Anxiolytic agents in selected cases
-Brief trial of systemic corticosteroids may be warranted in selected cases
-Localized small chronic lesions may be surgically removed
Optimal Therapeutic Approach for this Disease
Current treatment of choice is topical corticosteroids, often beginning with high-potency products such as clobetasol ointment or cream; due to the chronic nature of the condition, mid-potency topical steroids such as triamcinolone 0.025 % may be used for prolonged treatment or as a first choice in areas at risk of steroid atrophy. For persistent lichenified papules/plaques, intralesional triamcinolone 5mg/ml should be considered.
Occlusion is often helpful, both to improve steroid penetrance and perhaps more importantly to serve as a barrier to the itch-scratch cycle; this can be achieved through local application of a hydrocolloid dressing such as Duoderm over a mid-potency topical steroid, or larger areas on extremities may benefit from Unna boot occlusion with a topical steroid. Antipruritic emollients (menthol or colloidal oatmeal based) offer minimal benefit but can be applied over a large area as adjunctive treatment.
Discrete lichenified nodules of chronic duration can be addressed with surgical removal, generally as shave removal or rarely an elliptical excision.
For lesions unresponsive to topical steroids, topical immunomodulatory agents such as tacrolimus or pimecrolimus are an option; these agents can also be considered if concerned about atrophogenic effects from topical steroids.
Rarely, for widespread lesions, a short course of oral corticosteroids may help break the itch-scratch cycle, but should not be used long term. Sedating antihistamines may lessen the nighttime scratching that occurs in lighter sleep stages; options include hydroxyzine 10 to 25mg 1 to 2 hours before sleep, or doxepin 25 to 75mg; oral antianxiety medications (such as clonazepam/SSRI agents) can be considered in individual cases. For diffuse involvement with pruritus and lichen simplex chronicus, phototherapy can be initiated, favoring narrowband UVB.
After establishing the diagnosis on clinical and/or histopathologic findings, discussion of the diagnosis and identification of any "stressors" that may lead to the itch-scratch cycle should occur. Initial monitoring of response to therapy should occur approximately 1 month after the initiation of topical steroids, and then periodically based on the therapeutic choice, lesion location, and early response to therapy. Maintenance therapy may require intermittent use of mid- or high-potency topical steroids. If lesions do not respond after 1 month of therapy, a change of treatment should be considered; examples could include adding intralesional steroids or occlusive therapy at that time.
Patients and families should be aware of the habitual activity that may continue to produce these chronic lesions, as well as potential sleep disruption and psychic stress that can occur. On rare occasions, involvement of psychologic or psychiatric support may be necessary.
Unusual Clinical Scenarios to Consider in Patient Management
Lichen simplex chronicus of the anogenital region should be recognized; underlying atopic dermatitis may be present, and psychological stress as well as local irritants can aggravate this condition.
Additionally, the healthcare provider should be aware of the possibility of underlying allergic contact dermatitis from either an anogenital-specific product or transfer of other products to this area. Patch test allergens identified in earlier studies causing allergic contact dermatitis in the anogenital area include cinnamal, dibucaine, benzocaine, hydrocortisone-17-butyrate, budesonide, and less frequently quaternium-15, cobalt, formaldehyde, p-phenylenediamine and thiuram mix. Recently, methylchloroisothiazolinone/methylisothiazolinone, a preservative found in some moist toilet papers, has been identified as an allergen in anogenital dermatitis.
The clinician also needs to consider pruritus due to underlying systemic disease as a trigger for the clinical outcome of lichenification. Thus, in appropriate cases, a systemic evaluation with complete history and physical examination, age appropriate screenings as well as directed laboratory/imaging studies, may be indicated.
What is the Evidence?
Warshaw, EM, Furda, LM, Maibach, HI, Rietschel, RL, Fowlder, JF, Belsito, DV. "Anogenital dermatitis in patients referred for patch testing". Arch Dermatol. vol. 144. 2008. pp. 749-55.Member experts of the NACDG evaluated 575 patients with anogenital signs or symptoms (347 exclusively involved anogenital area), identifying relevant allergic patch test reactions; 73 patients met their definition of anogenital allergic contact dermatitis (ACD); ACD in the genital area can lead to lichen simplex chronicus.)
Virgili, A, Corazza, M, Bacilieri, S, Califano, A. "Contact sensitivity in vulval lichen simplex chronicus". Contact Dermatitis. vol. 37. 1997. pp. 296-7.(Evaluation of 270 women presenting to vulvar disorder clinic found 44 affected by vulvar lichen simplex chronicus; 48% had positive allergic patch tests with highest relevance to perfumes, preservatives and emulsifiers.)
Kantor, GR, Resnik, KS. "Treatment of lichen simplex chronicus with topical capsaicin cream [letter]". Acta Derm Venerol. vol. 76. 1995. pp. 161.(The authors performed a double-blind placebo controlled clinical trial with capsaicin 0.075% cream and vehicle on 7 patients without demonstrable improvement; benefit of capsaicin for this was considered questionable.)
Koca, R, Altin, R, Konuk, N, Altinyazar, HC, Kart, L. "Sleep disturbance in patients with lichen simplex chronicus and Its relationship to nocturnal scratching: A case control study". South Med Assoc. vol. 99. 2006. pp. 482-5.(Polysomnographic findings of 15 patients with lichen simplex chronicus demonstrated sleep disturbances in light and deep non-REM sleep patterns, which may be caused by nocturnal scratching episodes.)
(The authors provide a comprehensive succinct overview of lichen simplex chronicus of value to both the primary care provider and the dermatologist.)
Aschoff, R., Wozel, G. "Topical tacrolimus for the treatment of lichen simplex chronicus". J Dermatol Treat. vol. 18. 2007. pp. 115-7.(The authors provide successful treatment and resolution of facial lichen simplex with tacrolimus as an alternative treatment to atrophogenic topical steroids.)
Gardner, K, Davis, M, Richardson, D, Pittelkow, M. "The hazards of moist toilet paper". Arch Dermatol. vol. 146. 2010. pp. 886-90.
Juan, C-K, Chen, H-J, Shen, J-L, Kao, C-H. "(2015) Lichen Simplex Chronicus Associated With Erectile Dysfunction: A Population-Based Retrospective Cohort Study". PLoS ONE. vol. 10.(The authors conducted a nationwide population-based retrospective cohort study in Taiwan, finding that the incidence of erectile dysfunction was higher in the LSC cohort (LSC patients were 1.74 times more likely than controls to have been subsequently diagnosed with erectile dysfunction). In their study, LSC patients had more concomitant psychiatric disease, postulating that psychologic distress from chronic skin disease may contribute to the occurrence of erectile dysfunction.)
Konuk, N, Koca, R, Atik, L, Muhtar, S, Atasoy, N, Bostanci, B. " Psychopathology, depression and dissociative experiences in patients with lichen simplex chronicus". Gen Hosp Psychiatry. vol. 29. 2007.(The authors note a higher degree of general psychopathological symptoms in these patients, and dissociative experiences may occur more frequently; thus, a possible association between lichen simplex chronicus and psychiatric problems.)
Lynch, P. "Lichen simplex chronicus (atopic/neurodermatitis) of the anogenital region". Derm Ther. vol. 17. 2004. pp. 8-19.(An experienced clinician author shares thoughts on the condition, including common triggers, underlying conditions, and chronicity of the itch-scratch cycle, and provides general therapeutic approaches.) (The authors present four cases of allergic contact dermatitis to methylchloroisothiazolinone/methylisothiazolinone in moist toilet paper.)
Lotti, T, Buggiani, G, Pirgnano, F. "Prurigo nodularis and lichen simplex chronicus". Derm Ther. vol. 21. 2008. pp. 42-6.(The authors review the role of emotional stress and psychogenic factors inducing a pruritic sensation leading to the self-perpetuating itch-scratch cycle.)
Liao, YH, Lin, CC, Tsai-PP, WC, Sung, FC, Kao, CH. "Increased risk of lichen simplex chronicus in people with anxiety disorder: a nationwide population-based retrospective cohort study". Br J Dermatol. vol. 170. 2014. pp. 890-894.(This retrospective cohort study found increased prevalence of LSC among those with anxiety disorders, and supports addressing the psychological aspects as part of the management of LSC in those individuals.)
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