Lichen Striatus 

Updated: Jun 04, 2018
Author: June Kim, MD; Chief Editor: Dirk M Elston, MD 

Overview

Background

Lichen striatus is a rare, benign, self-limited linear dermatosis of unknown origin that predominantly affects children. Lichen striatus is clinically diagnosed on the basis of its appearance and characteristic developmental pattern following the lines of Blaschko.[1]

Pathophysiology

The skin is the primary organ system affected by lichen striatus. However, lichen striatus also may involve the nails.[2, 3]

Etiology

The etiology of lichen striatus is unknown. Many etiologic or predisposing factors are suggested for lichen striatus. The most commonly accepted hypothesis is the combination of genetic predisposition with environmental stimuli.

Atopy may be a predisposing factor. One group reported that 85% of patients with lichen striatus have a family history of atopic dermatitis, asthma, or allergic rhinitis. However, another report disputes this claim, stating that the incidence of atopy is no greater than that of the general population.

An autoimmune response may also be involved in lichen striatus. A case of lichen striatus has been reported during pregnancy, and it has been postulated that the pregnancy may have triggered an autoimmune response leading to the appearance of the eruption.[4] Lichen striatus has also been reported concurrently with vitiligo[5, 6] and after adalimumab[7] and etanercept.[8] Some reports simply suggest that lichen striatus is an inflammatory skin disease mediated by T cells. It has been reported 17 months after allogenic peripheral blood stem cell transplantation.[9]

An environmental (infectious or trauma[10] ) etiology has also been suggested. Familial cases,[11, 12] outbreaks among unrelated children in a shared living environment, and a possible seasonal variation suggest an environmental agent, such as a virus. Support of infectious involvement includes elevations of interleukin 1-beta in lichen striatus biopsy specimens.[13] However, results of viral testing have not conclusively proven this association. In addition, familial episodes of lichen striatus are not always simultaneous, signifying a possible genetic predisposition as a second explanation. Lichen striatus has been reported to occur shortly following immunization with BCG and hepatitis B vaccination, after UV exposure from a tanning bed,[14] following a prick from a pineapple leaf, after a bite by a bumblebee,[15] and after varicella and influenza infection.[16, 17]

One group of authors has suggested that epigenetic mosaicism may be involved. They hypothesize that lichen striatus is triggered by an immunologic reaction to an infection, which triggers methylation or demethylation of a partially silenced genomic element in predisposed patients.[13] A report of concurrent pityriasis rosea and lichen striatus may lend support to this theory. Human herpes viruses 6 and 7 have been implicated in the etiology of pityriasis rosea. The concurrent lichen striatus eruption may have manifested after being triggered by this viral infection.[18]

Lesions of lichen striatus follow the lines of Blaschko.[19, 13, 20, 21, 22] Blaschko lines are thought to be embryologic in origin. They are believed to be the result of the segmental growth of clones of cutaneous cells or the mutation-induced mosaicism of cutaneous cells. In lichen striatus, an acquired event (eg, viral infection) may allow an aberrant clone of cutaneous cells to express a new antigen, resulting in the phenotypic skin changes.

Epidemiology

Race

No racial predilection is recognized for lichen striatus.

Sex

No consensus exists on sex predilection in lichen striatus. Some studies show a 2- to 3-fold increased incidence in girls compared with boys, whereas others show an equal sex distribution.

Age

Lichen striatus is primarily a disease of young children. More than 50% of all lichen striatus cases occur in children aged 5-15 years. Other reports dispute this age range and claim that the median age of onset for lichen striatus is 3 years. Although lichen striatus is rare in both infants and adults, the disease can occur in persons of any age.[23, 24]

Prognosis

The prognosis of patients with lichen striatus is excellent. Recovery is complete. Lichen striatus lesions usually regress spontaneously within 1 year, with a range of 4 weeks to 3 years. Relapses of lichen striatus may occur, but these are uncommon.

Lichen striatus of the nail may take a protracted course, lasting from 6 months to 5 years.[25] Nail involvement resolves spontaneously without deformity.

 

Presentation

History

Lichen striatus often appears as a sudden eruption of small papules on an extremity. The papules are usually asymptomatic, reaching maximum involvement within several days to weeks. When lichen striatus patients are symptomatic, the most common complaint is pruritus. Lichen striatus is self-limited, but it may resolve with postinflammatory hyper or hypopigmentation.

Physical Examination

Lichen striatus appears as a continuous or interrupted, linear band consisting of small (1- to 3-mm) pink, tan, or skin-colored lichenoid papules. The papules may be smooth, scaly, or flat topped. Occasionally, a vesicular component is present. The band may range from a few millimeters to 1-2 cm wide and extends from a few centimeters to the full length an extremity. The lesions are usually unilateral and single on an extremity along the lines of Blaschko.[19, 13] In rare cases, they may be bilateral or occur in multiple parallel bands.[26, 27, 28] The lesions are most commonly located on a proximal extremity and less commonly on the trunk, head, neck, or buttock. A recent study suggests that facial lichen striatus is underreported and may represent up to 15% of all cases.[5] In darkly pigmented individuals, eruptions may appear as a bandlike area of hypopigmentation. Note the images below.

Extensive unilateral lichen striatus that affects Extensive unilateral lichen striatus that affects both the upper and lower extremities. Grouped keratotic lichenoid papules form plaques over the leg.
Lichen striatus over the inner thigh. Lichen striatus over the inner thigh.
Hypopigmented lichen striatus over the leg. Hypopigmented lichen striatus over the leg.

Nail involvement is uncommon in lichen striatus, with approximately 40 reported cases worldwide.[29, 3, 30] Nail lesions may occur before, after, or concurrently with the skin lesions. They may also be the only area of involvement. Often, only the medial or lateral portions are involved, and involvement is almost always restricted to one single nail. Nail changes may include longitudinal ridging, splitting, onycholysis, nail loss, hyperkeratosis of the nail bed, thinning or thickening of the nail plate, nail pitting, onychodystrophy, punctuate and striate leukonychia, and overcurvature of the nail plate.[31, 32] Dermoscopic examination may reveal sharply marginated, deep-white structures resembling Wickham striae and brown, keratotic, cerebriform structures with pinpoint red dots surrounded by a pale halo.[33]

Complications

Postinflammatory hyperpigmentation and hypopigmentation may last for several months to years after lichen striatus resolves.

 

DDx

Diagnostic Considerations

Also consider the following:

Differential Diagnoses

 

Workup

Procedures

Skin biopsy can be performed to confirm the diagnosis of lichen striatus, but this is rarely necessary.

In ambiguous cases, direct immunofluorescence with staining for Civatte bodies has been proposed to distinguish between lichen planus and lichen striatus. Stains for immunoglobulin M, immunoglobulin G, and complement C3 are positive in lichen planus and negative in lichen striatus.

Histologic Findings

The histopathologic results vary depending on the stage of evolution. Often, a polymorphic epidermal reaction pattern with variable spongiotic and lichenoid changes is seen in lichen striatus. However, unlike lichen planus, lichen striatus may result in a dense, usually perivascular, lymphohistiocytic infiltrate that extends deep into the dermis and that surrounds the hair follicles and eccrine sweat glands and ducts. Lymphoid infiltrates in the eccrine coil may mimic lupus or syringotropic mycosis fungoides, and the dense interface dermatitis may mimic conventional mycosis fungoides.[34, 35]  Granulomatous inflammation may also be present.

 

Treatment

Approach Considerations

Because lichen striatus is a self-limited disorder and because the lesions spontaneously regress within 3-12 months, no treatment is needed. The patient and family should be reassured. However, emollients and topical steroids may be used to treat associated dryness and pruritus, if present.[36] One report showed improvement with a combination of a topical retinoid and topical steroid.[37]

Photodynamic therapy using methyl aminolevulinic acid has been used for the treatment of lichen striatus.[38]

One study reported complete resolution in an adult with a short course of low-dose systemic corticosteroids[39] and another with a short course of acitretin.[40]

Tacrolimus and pimecrolimus have been successful in treating persistent and pruritic lesions on the face and extremities.[28, 41, 42, 43, 44] Tacrolimus has also been used successfully to treat nail abnormalities in lichen striatus.[25] Oral cyclosporine has also been used.[45]

 

Medication

Medication Summary

The goals of pharmacotherapy for lichen striatus are to reduce morbidity and prevent complications.

Corticosteroids, Topical

Class Summary

Corticosteroids have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli. Topical and intralesional steroids do not necessarily hasten resolution of lichen striatus.

Triamcinolone topical (Aristocort, Kenalog)

Topical triamcinolone is used for the treatment of inflammatory dermatoses responsive to steroids.It decreases inflammation by suppressing the migration of polymorphonuclear leukocytes and reversing capillary permeability. Triamcinolone affects the production of lymphokines and has inhibitory effects on Langerhans cells.

Clobetasol (Temovate)

Clobetasol is a slass I superpotent topical steroid. It suppresses mitosis and increases the synthesis of proteins that decrease inflammation and cause vasoconstriction.

Corticosteroids, Systemic

Class Summary

Corticosteroids have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli.

Prednisone (Deltasone, Prednisone Intensol, Sterapred, Sterapred DS)

Prednisone may decrease inflammation by reversing increased capillary permeability and suppressing PMN activity.

Immunomodulators

Class Summary

These agents exert anti-inflammatory effect by inhibiting T-lymphocyte activation. They are safer than topical steroids for prolonged use or in skin folds.

Pimecrolimus, topical 1% cream (Elidel)

Pimecrolimus is an immunomodulator; it inhibits T-cell proliferation and production of cytokines. Pimecrolimus differs from tacrolimus, as it does not inhibit antigen-presenting cells in the skin.

Tacrolimus, topical 0.03%, 0.1% (Protopic)

Tacrolimus is an immunomodulator; it suppresses cytokine release from T lymphocytes.

 

Questions & Answers