Linear lichen planopilaris of the face

Blaschko-linear lichen planus of the face: A retrospective study of 6 cases and a literature review

INTRODUCTION AND METHODS

Different clinical and histological variants of lichen planus (LP) exist, such as lichen planopilaris, pigmentosus, linear, or atrophic LP. Recently, some cases came to our attention of hyperpigmented and atrophic linear lesions of the face with lichenoid histology, suggesting a combination of these different variants. We carried out a single-center, retrospective descriptive study of 6 similar cases selected from our database and compared them with a literature review.

RESULTS

There were 4 males and 2 females of mean age 42 years. Each had linear lesions located on one side of the face. All lesions were initially itchy; they appeared hyperpigmented in all patients and atrophic in 5 cases. Biopsies indicated lichen planopilaris in 5 patients, with deep peri-eccrine involvement in 4 of them. Only 2 of the 6 patients had extra-facial lesions.

DISCUSSION AND LITERATURE REVIEW

We found 24 cases in the literature having similar clinical and histological aspects. Men aged around 37 years seemed particularly affected. An atrophic course was noticed in 10 patients. Such a clinicopathological picture may suggest differential diagnoses like lichen striatus, lupus erythematosus, lichen sclerosus atrophicus, or Moulin's linear atrophoderma. Early histopathological examination could be of precious assistance in allowing the initiation of effective treatment immediately as of the initial inflammatory phase, thereby limiting the risk of cosmetic sequelae such as atrophy or residual pigmentation.

CONCLUSION

We describe a form of facial lichen planus that is highly particular in terms of its follicular tropism, its blaschkoid distribution, its pigmented character, and its atrophic progression.

Lichenoid folliculitis: A unifying concept

Skin diseases presenting with keratotic papules, atrophy, cicatricial alopecia and/or "lichenoid" histopathologic changes have been described under at least 30 names. This family of diseases contains 2 subgroups, largely based on clinical features: keratosis pilaris atrophicans (KPA; including keratosis pilaris atrophicans faciei/ulerythema ophryogenes, atrophoderma vermiculatum, and keratosis follicularis spinulosa decalvans); and the lichen planopilaris (LPP) subgroup (including LPP, frontal fibrosing alopecia, Graham-Little-Piccardi-Lassueur Syndrome and fibrosing alopecia in a pattern distribution). An interface dermatitis with lichenoid inflammation is characteristic of the LPP group of disorders, but the literature provides scant information about the histopathology of the KPA group. Our experience has been that the 2 subgroups show a unifying histologic similarity as well as considerable clinical overlap. Because these conditions overlap clinically and histologically, we propose that the term lichenoid folliculitis (LF) be used to refer to this group of diseases, thus simplifying cumbersome nomenclature and highlighting the possibility of shared pathogenesis and treatment options.

Primary cicatricial alopecia: Lymphocytic primary cicatricial alopecias, including chronic cutaneous lupus erythematosus, lichen planopilaris, frontal fibrosing alopecia, and Graham-Little syndrome

Both primary and secondary forms of cicatricial alopecia have been described. The hair follicles are the specific target of inflammation in primary cicatricial alopecias. Hair follicles are destroyed randomly with surrounding structures in secondary cicatricial alopecia. This 2-part continuing medical education article will review primary cicatricial alopecias according to the working classification suggested by the North American Hair Research Society. In this classification, the different entities are classified into 3 different groups according to their prominent inflammatory infiltrate (ie, lymphocytic, neutrophilic, and mixed). Part I discusses the following lymphocytic primary cicatricial alopecias: chronic cutaneous lupus erythematosus, lichen planopilaris, frontal fibrosing alopecia, and Graham-Little syndrome.

Linear Lichen Planopilaris of the Face: Case Report and Review

We describe the case of a 45-year-old man who presented with a 5-month history of unilateral pruritic linear erythematous papules and atrophy on the chin and mandibular area. Dermoscopy showed areas of cicatricial alopecia with absence of follicular openings, perifollicular erythema and pigment. Lichen planopilaris of the face is a rare variant with only 13 cases reported in the literature.

Linear Lichen Planopilaris of the Trunk: First Report of a Case

Background:

Lichen planopilaris (LPP) is believed to be a follicular variant of lichen planus that affects pilosebaceous units, mainly of the scalp. An extremely rare variant of LPP is a linear form, which follows the lines of Blaschko. Of the five previously documented cases of linear LPP, all were limited to the face.

Objective:

We report the case of a 34-year-old male who presented with a nonpruritic eruption on the trunk consisting of erythematous, keratotic, folliculocentric papules following Blaschko's lines.

Results:

Biopsy revealed lichenoid and interface dermatitis involving the basilar epidermis and hair follicles, as well as apoptotic keratinocytes, consistent with LPP.

Conclusion:

This represents the first documented case of LPP, following the Blaschko's lines, in a nonfacial distribution.

Lichen planus in the lines of Blaschko

We describe three adolescents with eruptive linear lesions of the back, abdomen, and extremities distributed along the lines of Blaschko. Clinically one of these lesions resembled an epidermal nevus in its morphology and distribution. A biopsy specimen demonstrated the typical histology of lichen planus (LP). There have been fewer than 20 reported cases of childhood linear LP. Our patients demonstrate that linear LP sometimes may closely resemble an epidermal nevus and may auger the onset of more generalized LP or more involvement along the lines of Blaschko, that is, "Blaschkoian" disease. Previous studies have referred to this variant as zosteriform. Our cases are the fourth, fifth, and sixth cases of childhood LP reported to occur along the lines of Blaschko. Based on the clinical findings in our patients and a review of the English-language literature, we believe that linear LP is usually distributed along the lines of Blaschko and should be renamed lichen planus, Blaschko subtype.

Linear cutaneous lupus erythematosus in the lines of Blaschko

The lines of Blaschko describe distribution patterns which may represent embryologic developmental pathways. This distribution may occasionally be followed by some congenital and acquired skin disorders. We describe a child with linear cutaneous lupus erythematosus (LCLE) following Blaschko lines on the face.

Lines of Blaschko

The lines of Blaschko represent a pattern followed by many skin disorders. We review the clinical and histologic features of X-linked, congenital/nevoid, and acquired skin diseases that follow these lines. We also include cutaneous disorders that have a linear distribution but do not follow Blaschko's lines. Finally, we differentiate Blaschko's lines from other patterns on the skin such as dermatomes and Langer's lines.

Lichen striatus: a Blaschko linear acquired inflammatory skin eruption

An illustrative case report and a series of 18 well-documented cases of lichen striatus are presented. The mean age at diagnosis was 3 years (6 months to 14 years; median 2 years). The lesions were predominantly distributed on the trunk in 33% of cases and on the limbs in the remaining two thirds (upper limb: 48%; lower limb: 19%). Pruritus was noted in only 1 of 18 cases. Six cases were associated with clinical features of atopy and/or minor signs of atopic dermatitis (e.g., pityriasis alba). Two cases were considered to be clinically associated with lesions consistent with psoriasis. The mean duration was 9.5 months (4 weeks to 3 years; median 6 months). In one patient, two relapses occurred in 4 years. Hypochromic sequelae were noted in 50% of cases. Lichen striatus is the most common acquired self-limited linear eruption in childhood that follows Blaschko's lines. A new acronym is proposed to emphasize the developmental background of the disease: BLAISE for Blaschko linear acquired inflammatory skin eruption.