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.     

Multiple linear lichen planus in the lines of Blaschko

Summary The lines of Blaschko describe a distribution pattern which may represent embryologlcal development pathways. The distribution may occasionally be followed by some skin disorders. We report a patient who had multiple lesions of linear lichen planus which followed Blaschko's lines. There were multiple streaks affecting several different areas of the body.     

Mixed vitiligo of Blaschko lines: a newly discovered presentation of vitiligo responsive to combination treatment

Vitiligo, depigmenting disorder of the skin and mucous membranes, affects up to 1% of the population worldwide. It is classified into four major types: segmental, non‐segmental, mixed, and unclassified type. Non‐segmental vitiligo refers to non‐dermatomal distribution of lesions, while dermatomal distribution of lesions is present in patients with segmental vitiligo. Segmental vitiligo can also follow Blaschko lines – pathways of epidermal cell migration and proliferation during the development of the fetus. Here, we present patient with segmental and non‐segmental vitiligo following Blaschko lines with excellent therapeutic response to combined therapy. Prior to our report, a case of segmental and non‐segmental vitiligo followed by Blaschko lines was never described, therefore we suggest the term “mixed vitiligo of Blaschko lines” to describe this entity. This is also a rare case in which 90% repigmentation was achieved in patient with segmental and nonsegmental vitiligo following Blaschko lines in only 2 months of combined therapy.     

Linear scleroderma along Blaschko's lines in a patient with systematized morphea

We have previously shown that frontoparietal scleroderma en coup de sabre, a type of linear scleroderma that affects the face and scalp, follows the lines of Blaschko, but the question whether linear scleroderma that occurs in the limbs follows Blaschko's lines has not been answered. We describe the case of a 4-year-old girl with multiple morphea showing remarkable unilateral systematized distribution and whose linear lesions in the limbs appeared to follow Blaschko's lines. We suggest that linear scleroderma of the limbs, as well as frontoparietal scleroderma, may occur along the lines of Blaschko. Since both the unilateral distribution and the lesions along Blaschko's lines are the patterns created by genetic mosaicism, we suggest that a significant part of linear scleroderma and perhaps a smaller part of multiple morphea could be related to cutaneous mosaicism.     

Subacute cutaneous lupus erythematosus on the lines of Blaschko

We describe a 42-year-old woman who had erythemateous plaques with sharply demarcated margins and fine scaling on her right trunk and leg. The lesions had a linear distribution following the lines of Blaschko. Histological findings supported the diagnosis of subacute cutaneous lupus erythematosus (SCLE) on the lines of Blaschko. Treatment with systemic corticosteroids and anti-malarial agents resulted in remission. Up to now, eighteen cases of linear lupus erythematosus have been described. Linear lupus erythematosus mostly affects children presenting with lesions on the scalp that were classified as discoid lupus erythematosus. To our knowledge, this is the first case of subacute cutaneous lupus erythematosus on the lines of Blaschko.     

Blaschko线及相关疾病的研究

在临床工作中经常可以见到一些沿Blaschko线受累的皮肤病,皮损常具有一定的特征性.Blasehko线是由基因组嵌合体引起,临床表现有一定规律性.皮损外观比较奇特,常呈线状,节段型,旋涡状等分布.很多疾病都可沿Blaschko线分布,既包括先大或遗传性疾病,也包括后天或获得性疾病.一些皮肤外器官组织的疾病也有呈线状、带状、旋涡状等分布的规律.由于Blaschko线能从病因发生机制的方面阐述一些疾病,从而可对一些疾病的分类、病程发展等提供一些新认识.     

Lichen planus-like dermatosis with Blaschko line distribution: a case report

The authors describe the case of a healthy 46-year-old woman with a unilateral linear papular band on the left side of the trunk that followed the lines of Blaschko from the lower back extending to the left anterior side of her abdomen. The lesions were flat-topped, slightly elevated, violaceous, agglomerated lichenoid papules. The biopsy specimen demonstrated the typical histology of lichen planus. A working diagnosis of linear lichen planus was confirmed. Because congenital and/or nevoid skin disorders in a blaschkolinear distribution may have a delayed onset after birth, these lesions must be differentiated from acquired dermatoses following the lines of Blaschko. This distinction should be made in cases with isolated lesions, such as the case presented here.     

Striated lupus erythematosus following the Blaschko lines

We describe a striated cutaneous lupus erythematosus following the lines of Blaschko. These are lines along which cell populations having a common stem cell spread. If this stem cell is genetically altered, the lines of Blaschko are made visible by linear skin diseases. In the case of striated lupus erythematosus described here this genetic alteration remained unnoticed until, due to the influence of possible injury, the affected cells became antigenic, provoking a localized autoimmune disease.     

Eosinophilic cellulitis following the lines of Blaschko

Eosinophilic cellulitis is an inflammatory dermatosis of unknown aetiology. We describe a case following the lines of Blaschko, which may be the expression of cutaneous mosaicism, suggesting a possible underlying genetic predisposition for the development of Wells' syndrome.     

Linear cutaneous lupus erythematosus in the lines of Blaschko

Eleven patients with linear cutaneous lupus erythematosus following the lines of Blaschko have been previously reported in the literature. We describe a child with this entity following Blaschko lines on the trunk. The patient responded to oral hydroxychloroquine therapy combined with topical flurandrenolide tape resulting in resolution with atrophic scarring. The clinical and histological features of linear cutaneous lupus erythematosus are discussed and a review of the literature is presented.     

Multiple lichen striatus--an unusual presentation

A 2-year-old mare child presented with multiple hypopigmented, flat topped papules with a bilateral distribution along the lines of Blaschko. A 7-year-old girl presented with multiple hypopigmented macules arranged linearly along the left upper and lower limb and also on the back along the lines of Blaschko. Three discrete lines in three distinct anatomical areas in a case of lichen striatus do not appear to have been described.     

Double-lined frontoparietal scleroderma en coup de sabre

We describe a rare case of double-lined frontoparietal scleroderma en coup de sabre. The relationship to the distribution following the lines of Blaschko is discussed. In addition, we present a genetic hypothesis which is based on a mosaic state induced by postzygotic mosaicism. A patient with scleroderma en coup de sabre has a mosaic state for genes which predispose to susceptibility for linear scleroderma.     

Case of sequentially occurring lesions of facial lichen sclerosus following the lines of Blaschko

Extragenital lichen sclerosus (LS) is usually asymptomatic and appears as ivory- or porcelain-white macules, papules and plaques. It is most common on the neck, shoulders and upper portion of the trunk. To date, the linear form of extragenital LS corresponding to the lines of Blaschko on the trunk or limbs has been rarely reported. We describe a 25-year-old Korean woman with sequentially occurring lesions of extragenital LS confined to the face following the lines of Blaschko.     

The co-occurrence of segmental vitiligo and linear morphea in a pediatric patient and a review of the literature

Linear morphea and segmental vitiligo are both autoimmune diseases that are observed in the pediatric population, with rare reports of their co-existence. We describe a case of linear morphea and segmental vitiligo with an overlapping distribution in a pediatric patient and review the literature. Including our own case, we summarize 10 cases of co-occurring segmental vitiligo and morphea in pediatric patients; most of these lesions follow a blaschkolinear distribution, and none of the patients had autoimmune thyroid disease. Although uncommon, the coexistence of segmental vitiligo and linear morphea within lines of Blaschko can occur, and this case suggests that linear morphea and segmental vitiligo may be disorders related to genetic mosaicism.     

Congenital melanocytic nevi and nevus spilus have a tendency to follow the lines of Blaschko: an examination of 200 cases

There have been few reports about the characteristics of the pigmentary arrangement of congenital melanocytic nevi (CMN) and nevus spilus (NS). Though the lines of Blaschko, which don't correspond to other lines such as Langer's lines and skin dermatomes, are well known to be followed by some rare pigmentary disorders, the relationship between these two disorders and the lines of Blaschko has not been discussed. Therefore, through an examination of 200 cases, we investigated whether or not the arrangement of CMN and NS follow the lines of Blaschko. Thirty-nine out of 92 cases (42.4%) of CMN and 67 out of 108 cases (62.0%) of NS were considered to follow the lines of Blaschko. Today, the idea is widely accepted that two functionally different cells proliferate during early embryogenesis of the skin which is caused from mosaicism and, as a result, the lines of Blaschko appear visually. In our results, we found that there were some cases of CMN and NS which showed a relationship with the lines of Blaschko, which is meaningful considering that the lesions and the lines are both related to pigmentary gene anomalies. The result was compared with CMN and NS by the chi(2) test. NS showed a predominant tendency to follow the lines with a significant difference (P = 0.0055). This may indicate that the lines of Blaschko reflect more clearly the proliferation of the epidermal cells than other cells in growth of the skin of the embryo. Further studies are required to elucidate the reason why some cases follow these lines and others do not.     

Linear morphoea follows Blaschko's lines

Background  The aetiology of morphoea (or localized scleroderma) remains unknown. It has previously been suggested that lesions of linear morphoea may follow Blaschko's lines and thus reflect an embryological development. However, the distribution of linear morphoea has never been accurately evaluated.
Objectives  We aimed to identify common patterns of clinical presentation in children with linear morphoea and to establish whether linear morphoea follows the lines of Blaschko.
Methods  A retrospective chart review of 65 children with linear morphoea was performed. According to clinical photographs the skin lesions of these patients were plotted on to standardized head and body charts. With the aid of Adobe Illustrator a final figure was produced including an overlay of all individual lesions which was used for comparison with the published lines of Blaschko.
Results  Thirty-four (53%) patients had the en coup de sabre subtype, 27 (41%) presented with linear morphoea on the trunk and/or limbs and four (6%) children had a combination of the two. In 55 (85%) children the skin lesions were confined to one side of the body, showing no preference for either left or right side. On comparing the overlays of all body and head lesions with the original lines of Blaschko there was an excellent correlation.
Conclusions  Our data indicate that linear morphoea follows the lines of Blaschko. We hypothesize that in patients with linear morphoea susceptible cells are present in a mosaic state and that exposure to some trigger factor may result in the development of this condition.     

Unilateral Blaschkoid lichen planus involving the entire half of the body, a unique presentation

A large number of congenital as well as acquired skin disorders assume a characteristic morphological pattern following the Blaschko lines. Lichen planus (LP) is an acquired inflammatory disorder that can come with different faces. Linear lesions are frequently seen but cases of zonal (zosteriform) or whorled appearance have rarely been described in the literature. We describe an even rarer presentation in a 30-years-old man who had unilateral pruritic violaceous lesions over right half of body characteristically following lines of Blaschko with clinical and histological morphology typical of LP.     

Acquired Blaschko Dermatitis: Acquired Relapsing Self-Healing Blaschko Dermatitis

Acquired Blaschko dermatitis is a rare disease with acquired unilateral relapsing inflammatory linear lesions along Blaschko's lines. Histopathology reveals spongiotic dermatitis. “Blaschkite de l'adulte” and “acquired relapsing self-healing Blaschko dermatitis” have been suggested as names for this condition. Our patient was a 27-year-old man with a 6 month history of repeated, unilateral, slightly pruritic, discrete and grouped erythematous papules and papulovesicles on the left side of the upper limbs and trunk along Blaschko's lines. Histologic examination showed subacute spongiotic dermatitis. The condition showed excellent improvement after treatment with systemic corticosteroid for 2 months. Only a few cases have been reported. We propose a new designation and describe a patient who represents the first reported case of acquired Blaschko dermatitis in Korea.     

Linear patterns of the skin and their dermatoses

Knowledge about the linear patterns of the skin is a key competence of dermatologists. Four major groups of linear patterns can be distinguished: Langer lines, dermatomes, Blaschko lines and exogenous patterns. Langer lines run in the direction of the underlying collagen fibers (least skin tension) and play an important diagnostic role for some exanthematous skin diseases. In the thoracodorsal region, the distribution of the Langer lines gives rise to what is referred to as a ’Christmas tree pattern’. A dermatome is an area of skin that is supplied by a single spinal nerve. Disorders with a neuronal origin follow this pattern of distribution. The lines of Blaschko delineate the lines of migration of epidermal cells during embryogenesis. Exogenous linear patterns are caused by external factors. The present CME article will highlight important skin disorders that primarily present in the form of one of the aforementioned patterns. In addition, we will also address skin conditions that may secondarily follow with these patterns (or distinctly not do so) as the result of various mechanisms such as the Koebner phenomenon, reverse Koebner phenomenon, and Wolf’s isotopic response.     

A Case of Linear Exacerbation of Atopic Dermatitis with Secondary Prurigo Nodularis

Inflammatory acquired Blaschko-linear dermatoses (IABLD) are a continuous concept involving diseases such as lichen striatus, blaschkitis, and atopic dermatitis. However, atopic dermatitis that showed increase in severity along Blaschko lines is rarely reported on its own. Herein, we report a rare case of atopic dermatitis with secondary prurigo nodularis along Blaschko lines, which may be valuable in broadening the concept of IABLD. A 28-year-old male presented with multiple, pruritic, brownish nodules on the left lower extremity along Blaschko lines for 3 to 4 years. The patient had atopic dermatitis since childhood. Histopathologic findings revealed compact orthohyperkeratosis, hypergranulosis, spongiosis, and irregular acanthosis in the epidermis. Fibrosis with vertically arranged collagen fibers and perivascular lymphohistiocytic infiltration were shown in the upper dermis. We diagnosed the case as secondary prurigo nodularis along Blaschko lines, accompanied by the preceding atopic dermatitis. We hypothesized that the patient’s underlying atopic dermatitis increased in severity along Blaschko lines, and prurigo nodularis occurred due to frequent scratching. The lesions improved with topical methylprednisolone cream, oral antihistamines and intralesional triamcinolone injection.