Unilateral linear psoriasis with palmoplantar, nail, and scalp involvement

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.

Nail lichen striatus: Is dermoscopy useful for the diagnosis?

BACKGROUND/OBJECTIVES

Lichen striatus is a unilateral inflammatory dermatosis that rarely affects the nail unit. When the inflammation involves the nail unit, classic lichenoid nail changes are easily detectable, more often limited to only one portion of the nail. Usually the nail dystrophy coexists with periungual skin papules following Blaschko's lines, but it could also be an isolated feature. Because a nail unit biopsy presents difficulties in execution, especially in a child, the aim of our study has been to describe the nail unit dermoscopy features of lichen striatus hoping to provide a valid aid to clinicians in the diagnosing this rare disorder.

METHODS

We reviewed the images of five pediatric patients with a clinical diagnosis of lichen striatus. Data about sex, age, localization, predisposing/triggering factors, and associated disorders are reported.

RESULTS

The diagnosis of lichen striatus can be challenging as there are clinically overlapping features with related dermatoses. A common diagnostic pitfall occurs with inflammatory linear verrucous epidermal nevus and lichen planus. Involvement of only one part of the nail plate with linear longitudinal fissuring, ridging, and distal splitting, especially if seen with perionychial skin lesions, is characteristic of lichen striatus.

CONCLUSIONS

Nail lichen striatus is rare, and there is sparse published literature on it. When the changes in lichen striatus are limited to the nail, the diagnosis may easily be missed. We therefore believe that dermoscopy is an important diagnostic maneuver, which should be integrated into the evaluation of patients with potential lichen striatus, and in particular is helpful for clinicians unwilling or unable to perform a nail unit biopsy.

Clinical and Therapeutic Aspects of Linear Psoriasis: A Study of 30 Cases

BACKGROUND

Psoriasis affects 2-4% of the population, with the most common clinical type being plaque psoriasis. The linear form of psoriasis is very rare. The literature on linear psoriasis (LP) consists of only case reports, and data are few.

OBJECTIVE

This study aimed to better understand LP in a large-scale study.

PATIENTS AND METHODS

We retrospectively retrieved the medical records from 14 French medical centers of patients newly diagnosed clinically with LP, with or without the support of histology, between 1 February and 31 July 2015. For each case, we assessed the clinical features, treatments and treatment efficacy.

RESULTS

In total, 30 cases of LP (mean age 26.8 years, 13 males) were reported. Mean age at onset of LP was 20.0 years, with 18 developing LP in childhood. Ten patients had a family history of psoriasis, and two had psoriatic arthritis. A total of 19 cases were linear at onset, with concomitant classical psoriasis; these were termed "superimposed" LP. The remaining 11 cases were not associated with classical psoriasis and were termed "isolated" LP. In four of the superimposed cases, LP developed when the patient was receiving systemic treatment: methotrexate (n = 2), etanercept (n = 1) or infliximab (n = 1). Topical steroids were effective in 76% of cases in which they were used, and systemic treatment was effective in < 66%. Treatments were less effective in LP than in classical psoriasis.

DISCUSSION

We identified a wide range of LP, with two profiles: isolated LP and superimposed LP. Topical treatment usually evoked clinical response, with relative resistance to systemic therapy. Methotrexate and anti-tumor necrosis factor (TNF)-α therapies can possibly unmask LP.

Successful Treatment of Inflammatory Linear Verrucous Epidermal Nevus with Concomitant Psoriasis Using Etanercept

Linear psoriasis is a rare form of the disease characterized by the linear distribution of lesions involving dermatome or along Blaschko's lines. Clinically, it may resemble inflammatory linear verrucous epidermal nevus; a combination of history, skin examination, and histopathology are required to ensure correct diagnosis and appropriate therapy. This paper describes a case of a 23-year-old male presenting with unilateral erythematous scaly plaques arranged in a linear path on the left leg. Etanercept was initiated after poor response to adalimumab. Improvement of his psoriasis was noted, with PASI 75 reduction after 24 weeks of treatment. Clinical studies have shown excellent efficacy of etanercept, and our patient well tolerated treatment with etanercept for 52 weeks without any adverse effects.

Isolated linear blaschkoid psoriasis

Linear psoriasis (LPs) is considered a rare clinical presentation of psoriasis, which is characterized by linear erythematous and scaly lesions along the lines of Blaschko. We report the case of a 20-year-old man who presented with asymptomatic linear and S-shaped erythematous, scaly plaques on right side of his trunk. The plaques were arranged along the lines of Blaschko with a sharp demarcation at the midline. Histological examination of a skin biopsy confirmed the diagnosis of psoriasis. Topical calcipotriol and betamethasone dipropionate ointments were prescribed for 2 months. A good clinical improvement was achieved, with reduction in lesion thickness and scaling. In patients with linear erythematous and scaly plaques along the lines of Blaschko, the diagnosis of LPs should be kept in mind, especially in patients with asymptomatic lesions of late onset.

Involucrin in the differential diagnosis between linear psoriasis and inflammatory linear verrucous epidermal nevus: a report of one case

Inflammatory linear verrucous epidermal nevus is a variant of verrucous epidermal nevus, characterized by recurrent inflammatory phenomena. Despite well-established clinical manifestations, the differential diagnosis between inflammatory linear verrucous epidermal nevus and linear psoriasis remains difficult. Clinical history, physical examination and histopathology analysis may not be sufficient to confirm the diagnosis. We report the case of a 4-year-old girl in which the involucrin immunostaining was helpful in the diagnosis of inflammatory linear verrucous epidermal nevus. Our findings confirm that involucrin immunohistochemistry is a useful tool in such cases.

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.

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.

Does Inflammatory Linear Verrucous Epidermal Nevus Represent a Segmental Type 1/Type 2 Mosaic of Psoriasis?

BACKGROUND

A 6-year-old girl with a symmetric linear eruption on both of her legs, clinically and histologically resembling inflammatory linear verrucous epidermal nevus (ILVEN) or linear psoriasis (LP), with concomitant psoriasis of the guttata type and a positive family history of psoriasis is presented. The questions as to whether LP actually exists and ILVEN represents a distinct entity are still under debate.

OBJECTIVE AND METHODS

The recent literature concerning case reports of ILVEN and LP is reviewed.

RESULTS

Case reports of ILVEN and LP can be subdivided into four different groups: (1) ILVEN with or without concomitant psoriasis, only in part reacting to antipsoriatic treatment, (2) ILVEN without concomitant psoriasis, (3) LP with concomitant psoriasis vulgaris, with both groups 2 and 3 reacting successfully to antipsoriatic treatment, and (4) LP without concomitant psoriasis vulgaris and with no family history of psoriasis (very rarely reported).

CONCLUSION

It is hypothesized that inflammatory linear verrucous eruption besides nevoid psoriasis/LP represents a further segmental type 1/type 2 mosaic of psoriasis which, if a (verrucous) epidermal nevus exists, shows a high affinity of occurrence in close context to such a nevus. Heritability is thought to be possible.