Congenital psoriasis following the lines of Blaschko

Clinical Characteristics and Therapeutic Aspects of Blaschko Linear Psoriasis

INTRODUCTION

Blaschko linear psoriasis (BLP) is characterized by the linear distribution of psoriatic skin lesions along the Blaschko lines. BLP can be divided into type I and type II, mainly on the basis of clinical manifestations. BLP can easily cause psychological burdens in patients and clinical confusion for physicians. Here, we summarize clinical cases to provide a better understanding of BLP.

METHODS

The subjects included patients with BLP who visited our dermatology departments and those reported in the literature obtained from the PubMed and Wanfang databases. Quantitative data were presented as means ± SD (standard deviation), and qualitative data were represented by the frequency. Student's t test was employed to compare means, whereas chi-square tests were used for analyzing qualitative data.

RESULTS

A total of 74 patients with BLP (5 our patients, 69 from literature) were included, with 61 type I and 13 type II patients. We summarize BLP's characteristics as follows: (1) More frequent in male individuals, especially in type II; (2) Earlier onset than classical psoriasis; (3) Mainly distributed unilaterally, and no preference for left or right site; (4) Asymptomatic or slight pruritus; (5) Mostly negative family history of psoriasis; (6) Possible involvement of the nails/scalp (mainly for type II); (7) Possible exogenous triggering or aggravation factors; (8) Possible concomitant classical plaque or guttate psoriasis lesions, especially in type II; (9) Conforming to histopathology features of classical psoriasis; (10) Relatively favorable response to antipsoriatic treatment, although poor for superimposed areas in type II.

CONCLUSION

This study analyzed the clinical characteristics and therapeutic aspects of BLP. Compared with published studies, we have new findings, such as gender bias. Besides traditional antipsoriatic treatment, a personalized selection of biologics may also be a promising choice. Dermatologists should recognize and understand the significance of this disease, and provide patients with appropriate psychological counseling and clinical treatments.

Mosaicism in genodermatoses

Genodermatoses are inherited disorders presenting with cutaneous manifestations with or without the involvement of other systems. The majority of these disorders, particularly in cases that present with a cutaneous patterning, may be explained in the context of genetic mosaicism. Despite the barriers to the genetic analysis of mosaic disorders, next-generation sequencing has led to a substantial progress in understanding their pathogenesis, which has significant implications for the clinical management and genetic counseling. Advances in paired and deep sequencing technologies in particular have made the study of mosaic disorders more feasible. In this review, we provide an overview of genetic mosaicism as well as mosaic cutaneous disorders and the techniques required to study them.

Linear psoriasis - a case report

A 56-year-old woman presented with a 3-month history of erythematous plaques covered by scales and limited to the right side of her body. The plaques were arranged along Blaschko's lines with a marked mid-line cutoff. The histopathologic analysis of a skin biopsy in conjunction with the anamnesis allowed the diagnosis of linear psoriasis. Our patient showed a good clinical response to antipsoriatic treatment.

[Blasch-kolinear psoriasis revealed by infliximab therapy]

BACKGROUND

Blaschko-linear psoriasis is a rare disease about which only a few publications have appeared in the literature. This form of psoriasis poses problems of differential diagnosis with regard to other forms of inflammatory Blaschko-linear dermatoses. Herein, we report an original case, the linear nature of which was revealed by treatment with infliximab.

CASE REPORT

A 29-year-old man presented chronic psoriasis present for 17 years and resistant to various forms of systemic therapy. Treatment with infliximab 5mg/kg given on D1, D15 and two-monthly, thereafter resulted in practically complete resolution of all skin lesions after the fourth infusion. The only remaining lesions were psoriatic erythematous-squamous, non-pustular lesions with a Blaschko-linear pattern, limited to one side, on the left arm and left leg. These lesions persisted after 10 courses of infliximab, although no other lesions reappeared.

DISCUSSION

This case was original in terms of the revelation of Blaschko-linear lesions during treatment with infliximab, despite the complete disappearance of diffuse psoriatic plaques, thus suggesting the existence in this patient of two cell populations, each having a different response to biotherapy.

Congenital psoriasis: case report and literature review

While childhood psoriasis is fairly common, congenital psoriasis appears to be rare and has not been well characterized. We present a patient with histologically confirmed congenital psoriasis. By reviewing the literature, we aim to both define this disease and compare it to infantile and childhood psoriasis. Electronic searches found articles reporting patients with biopsy-proven congenital psoriasis. We recorded clinical features, such as family history, anatomic involvement, and disease severity. We compared these data with previous descriptions of infantile and childhood psoriasis. We included nine patients with congenital psoriasis in our analysis. No patient had a first-degree family history of psoriasis. While the face, scalp, chest, and trunk were frequently involved, the buttocks generally were spared. Several patients had persistent disease despite therapy. In this series, congenital psoriasis differed from infantile and childhood psoriasis in several respects. Specifically, congenital psoriasis was associated with a lower prevalence of relevant family history, which could increase over time, and a different pattern of anatomic involvement, which may reflect exposure to age-associated environmental factors. Although several patients with congenital psoriasis had severe disease, this likely represents publication bias. Additional reports of congenital psoriasis with extended follow-up are needed to better characterize this condition.

Superimposed segmental manifestation of polygenic skin disorders

In common acquired skin disorders with a polygenic background such as psoriasis, a linear or otherwise segmental arrangement may sometimes be noted. The segmental involvement tends to be rather severe and may be associated with milder, nonsegmental lesions of the same disorder. Such cases may be best explained by an early postzygotic event in the form of loss of heterozygosity involving one of the genes that predispose to the disorder. The following pertinent examples are reviewed in this article: psoriasis vulgaris, pustular psoriasis, atopic dermatitis, lichen planus, systemic lupus erythematosus, pemphigus vulgaris, vitiligo, graft-versus-host disease, granuloma annulare, erythema multiforme, and drug eruption to ibuprofen. Such cases should not be categorized as a "type 2 segmental manifestation" because this term exclusively applies to monogenic traits, whereas in polygenic disorders the more descriptive term "superimposed segmental manifestation" seems appropriate. The concept of early loss of heterozygosity offers a plausible explanation as to why: the segmental involvement tends to appear at a rather young age and often precedes the development of milder, nonsegmental lesions of the same disorder; the segmental lesions are notoriously difficult to treat; and family members may show the disorder in its nonsegmental form. On the other hand, the theory of isolated versus superimposed segmental manifestation may help to elucidate the origin of polygenic skin disorders at the molecular level.

Linear naevoid psoriasis along lines of Blaschko

Congenital linear naevoid psoriasis along Blaschko's lines on the thigh of a 3-year-old girl is reported. The history of asymptomatic, erythematous scaly lesions since birth, the peculiar distribution and the histopathology confirmed the diagnosis.

Bart syndrome: the congenital localized absence of skin may follow the lines of Blaschko. Report of six cases

Three cutaneous manifestations are characteristic of Bart syndrome: congenital localized absence of skin (CLAS), mucocutaneous blistering, and nail abnormalities. Six cases of Bart syndrome are herein reported. Localized absence of skin is present at birth, particularly on the anterior aspects of the lower extremities and dorsa of the feet. Physical trauma in utero has been proposed as a mechanism to explain the denuded areas on the limbs. The recurrent, highly similar pattern of the congenital defect in regard to location and clinical appearance in our patients and in most of the reported cases strongly suggests that trauma is too simplistic an explanation. Because of the observed bilateral and symmetric distribution of denuded areas in an S-shaped broad band, their sharply demarcated borders, the involvement of the toe webs, and the frequent similar involvement of the soles, we suggest that congenital localized absence of skin in Bart syndrome may follow the lines of Blaschko.