Lichen simplex chronicus L28.0

A characteristic, yet nonspecific, distinctly chronic, circumscribed, aggravated by friction, itchy, plaque-like, inflammatory-lichenoid skin reaction pattern that is morphologically and clinically characterized by its varied locations and chronic mechanical irritation. In the literature, various names have been coined for lichen simplex chronicus in different regions (see below); however, these should not be considered separate entities.    

Unresolved

A "minus" variant ofatopic dermatitis is being discussed.

However, atopic features may be completely absent.

Associations have been described with gastrointestinal disorders, liver diseases, gallbladder disorders, and diabetes mellitus.

Psychogenic factors: Although patients often complain of symptoms, upon patient inquiry, scratching emerges as the underlying cause—an automatic action that is sometimes perceived as “pleasurable.”   

w>m; First manifestation in middle and higher adulthood, less often in childhood.

Especially the neck area (lichen nuchae): "thoughtful" rubbing or scratching of the neck

Chin area (follicular keratosis of the chin, see there): resting the chin on the hands

Extensor surfaces of the forearms

Extensor surfaces of the lower legs (pretibial pruritic papular dermatosis): Rubbing the lower legs together

Elbows: caused by leaning on them (no itching) 

Inner thighs and ankle regions (frequent rubbing of the ankles against each other; a verrucous component is possible— verrucous lichen simplex chronicus)

Sacral region (friction effects associated with idiopathic itching—see also notalgia paresthetica)

Scrotum and vulva (contributing factors here include occlusive effects caused by tight-fitting clothing—Chan MP et al. 2015). See also under scrotal dermatitis, vulvar dermatitis.

The main symptom is localizeditching that is perceived as severe and agonizing, which can intensify in stressful situations. There are plaques measuring 10–15 cm in size, typically round or oval, less commonly elongated or strip-shaped, and typically exhibiting a “three-zone phenomenon”:

• extensive central lichenification
• lichenoid nodules toward the edges
• peripheral hyperpigmentation.

The plaques consist of isolated—or aggregated into plaques—solid, flat, gray to brownish-red or skin-colored lichenoid papules measuring 0.1–0.2 cm in size, which are often scratched. When viewed from the side, the lesions often exhibit a dull (lichenoid) sheen. The three-zone structure gives way to a homogeneous, flat appearance of the coarse papules/plaques when a verrucous component overlies them (severe itching with consequent abrasion).  

Pronounced, clumsy acanthosis with irregular elongation of the mostly bulbously raised reteleasts. Severe orthohyperkeratosis with focal parahyperkeratosis. Wide capillaries in the papillary stratum and in the upper dermis. Predominantly vascular, but also diffuse, rather sparse lymphohistiocytic infiltrate. Mostly distinct fibrosis of the dermis, with collagen bundles running vertically to the epidermis. The histological picture requires an exact clinical correlate for its interpretation.

Allergic contact dermatitis; Drug reaction; Atopic eczema; Lichen planus; Prurigo nodularis; Lichen amyloidosus, Nummular dermatitis

The disease usually proves to be extremely resistant to therapy.

Therapeutic guidelines:

• The therapy of lichen simplex chronicus is to be applied as a long-term strategy!
• It should be made clear that this is an eminently chronic disease!
• If necessary, a psychotherapist should be involved in the therapy at an early stage!
• Antihistamines can be used against the itching. The success is moderate. Better are glucocorticoid-containing ointments e.g. betamethasone valerate R029 or triamcinolone acetonide-containing creams or ointments.
• For secondary infections, combination therapeutics such as clioquinol-containing glucocorticoid externals(e.g., Locacorten-Vioform) or triclosan/glucocorticoid combinations (Duogalen cream) are indicated.
• Occlusive dressings can always be applied in the short term.
• Alternatively, tacrolimus-containing topical preparations (0.03% Protopic ointment) can be used.

Good results are obtained with multiple injections of glucocorticoid crystal suspension (Volon A 10 crystal suspension mixed with 1% xylocaine).

In suitable localization, cryosurgery (open spray procedure, freeze 1-2 times briefly) can be used and, if necessary, combined with triamcinolone acetonide subinjection. Own experience is quite positive.

If the localization is suitable, local PUVA therapy can be used. In the case of genital localization, in addition to the above measures, we recommend consistent application of sitz baths, if necessary with tanning additives (e.g. Tannosynt).

Dermatological climatic therapy (North Sea baths) brings very good results in some cases.

Clinic and histology are decisive for the diagnosis. The absence or presence of signs of atopy (increase in IgE levels, sensitization in the epicutaneous and prick test) does not help in the diagnosis!

In the case of genital or perianal lichen simplex chronicus it is recommended to wear suitable underwear that does not fit tightly.

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