Coexistence of pseudoxanthoma elasticum-like papillary dermal elastolysis and linear focal dermal elastosis

Linear focal elastosis

Linear focal elastosis (LFE) is an uncommon, benign, acquired elastotic condition with uncertain pathogenesis. It is characterized clinically by asymptomatic, multiple, yellowish, elevated, irregularly indurated, striae-like lines or bands distributed horizontally across the lower and middle part of the posterior trunk. The histopathological hallmark of LFE is a focal increase of elastic fibres in the dermis. The differential diagnosis is varied, and striae distensae is the closest mimic of LFE. Response of LFE to treatment is often poor. The focus of this article is to provide insights into this condition for dermatologists.

Pseudoxanthoma elasticum and skin: Clinical manifestations, histopathology, pathomechanism, perspectives of treatment

Pseudoxantoma elasticum (PXE), also known as Groenblad-Strandberg syndrome, is a rare heritable disease with an estimated prevalence of 1:50,000 in the general population. PXE is considered a prototype of multisystem ectopic mineralization disorders and it is characterized by aberrant mineralization of soft connective tissue with degeneration of the elastic fibers, involving primarily the eyes, the cardiovascular system, and the skin. Cutaneous lesions consist of small, asymptomatic, yellowish papules or larger coalescent plaques, typically located on the neck and the flexural areas. PXE is caused by mutations in the ABCC6 (ATP-binding cassette subfamily C member 6) gene that encodes a transmembrane ATP binding efflux transporter, normally expressed in the liver and the kidney; however, the exact mechanism of ectopic mineralization remains largely unknown. The histological examination of cutaneous lesions, revealing accumulation of pleomorphic elastic structures in middermis, is essential for the definitive diagnosis of PXE, excluding PXE-like conditions. PXE is currently an intractable disease; although the cutaneous findings primarily present a cosmetic problem, they signify the risk for development of ocular and cardiovascular complications associated with considerable morbidity and mortality. The purpose of this review is to present a comprehensive overview of this rare form of hereditary connective tissue disorders, focus on the pathogenesis, the clinical manifestation, and the differential diagnosis of PXE. Emphasis is also placed on the management of cutaneous lesions and treatment perspectives of PXE.

Role of Steroid Therapy in Pseudoxanthoma Elasticum-like Papillary Dermal Elastolysis

Pseudoxanthoma Elasticum-like Papillary Dermal Elastolysis (PXE-PDE) is a peculiar idiopathic elastolytic disorder that clinically resembles Psudoxanthoma elasticum (PXE). It is histologically characterized by a total or partial loss of elastic fibers in the papillary dermis. It more often affects elderly women and is characterized by asymptomatic and symmetrical yellowish papules localized predominantly on the neck, supraclavicular regions, and flexural areas. After analyzing a series of cases and the recent literature suggesting that glucocorticoids may down-regulate the elastin gene expression and elastin mRNA, in cultured human skin fibroblasts, we think that high dose and prolonged steroid therapy may contribute to the appearance of PXE-PDE lesions.

Histopathology of pseudoxanthoma elasticum and related disorders: histological hallmarks and diagnostic clues

Among ectopic mineralization disorders, pseudoxanthoma elasticum (PXE)-a rare genodermatosis associated with ocular and cardiovascular manifestations-is considered a paradigm disease. The symptoms of PXE are the result of mineralization and fragmentation of elastic fibers, the exact pathophysiology of which is incompletely understood. Though molecular analysis of the causal gene, ABCC6, has a high mutation uptake, a skin biopsy has until now been considered the golden standard to confirm the clinical diagnosis. Although the histological hallmarks of PXE are rather specific, several other diseases-particularly those affecting the skin-can present with clinical and/or histological characteristics identical to or highly resemblant of PXE. In this paper, we will summarize the histopathological features of PXE together with those of disorders that are most frequently considered in the differential diagnosis of PXE.

Unusual and recently described cutaneous atrophic disorders

Cutaneous atrophic conditions are typically caused by changes in the dermis or subcutaneous tissue, sometimes consisting of the loss of a single fiber type. Since a significant decrease of subepidermal tissue is necessary for these lesions to be macroscopically atrophic, many conditions may not be appreciated as atrophy in the clinical setting. Clinicians should be familiar with the common or classic disorders causing cutaneous atrophy; however, there are a few new or rarely described atrophic conditions which are more difficult to identify and may not be atrophic clinically. This paper serves to describe the salient clinical and histological features of these new or rare disorders.

A case of fibroelastolytic papulosis on the neck of a young man

Fibroelastolytic papulosis of the neck (FEPN) encompasses a spectrum of two disorders that were previously reported as pseudoxanthoma elasticum-like papillary dermal elastolysis (PXE-PDE) and white fibrous papulosis of the neck (WFPN). The clinical presentation of FEPN is asymptomatic to mildly pruritic whitish-yellow papules that may coalesce into cobblestone patterned plaques that resemble pseudoxanthoma elasticum (PXE). The histology is characterized by a decrease or loss of elastic fibers in the papillary dermis and this is sometimes accompanied by a minimal or nodular increase of dermal collagen fibers. We report here on a 28-year-old Korean man with asymptomatic, multiple, skin-colored to slightly yellowish, match-head sized, cobblestone-patterned papules on the neck, and these were histologically consistent with FEPN and the papules showed slightly increased dermal collagen associated with decreased and fragmented elastic fibers, elastin and tropoelastin. The pathogenesis of FEPN in this case might have been related with mild dermal inflammation, followed by fragmentation, elastolysis and increased dermal collagen.

[Papillary dermal elastolysis similar to pseudoxanthoma elasticum]

Papillary dermal elastolysis similar to pseudoxanthoma elasticum is an elastolytic disorder characterized by cutaneous lesions on the neck and in the supraclavicular region that are clinically similar to pseudoxanthoma elasticum, with no systemic complications. The histological examination shows a loss of elastic fibers in the papillary dermis. We report a case in a 76-year-old woman with typical lesions on the neck.

Acquired disorders of elastic tissue: part I. Increased elastic tissue and solar elastotic syndromes

Elastic fibers in the extracellular matrix are an integral component of dermal connective tissue. The resilience and elasticity required for normal structure and function of the skin may be attributed to the network of elastic tissue. Advances in our understanding of elastic tissue physiology provide a foundation for studying the pathogenesis of elastic tissue disorders. Many acquired disorders are nevertheless poorly understood due to the paucity of reported cases. Several acquired disorders in which accumulation or elastotic degeneration of dermal elastic fibers produces prominent clinical and histopathologic features have recently been described. They include elastoderma, linear focal elastosis, and late-onset focal dermal elastosis and must be differentiated from better-known disorders, among them acquired pseudoxanthoma elasticum, elastosis perforans serpiginosa, and Favré-Racouchot syndrome. Learning objective At the conclusion of this learning activity, participants should understand the similarities and differences between acquired disorders of elastic tissue that are characterized by an increase in elastic tissue, as well as the spectrum of solar elastotic dermatoses.

Acquired disorders of elastic tissue: Part II. decreased elastic tissue

Elastic fibers in the extracellular matrix are integral components of dermal connective tissue. The resilience and elasticity required for normal structure and function of the skin are attributable to the network of elastic tissue. Advances in our understanding of elastic tissue physiology provide a foundation for studying the pathogenesis of elastic tissue disorders. Many acquired disorders are nevertheless poorly understood owing to the paucity of reported cases. Several acquired disorders in which loss of dermal elastic tissue produces prominent clinical and histopathologic features have recently been described, including middermal elastolysis, papular elastorrhexis, and pseudoxanthoma-like papillary dermal elastolysis, which must be differentiated from more well-known disorders such as anetoderma, acquired cutis laxa, and acrokeratoelastoidosis. Learning objective At the conclusion of this learning activity, participants should have an understanding of the similarities and differences between acquired disorders of elastic tissue that are characterized by a loss of elastic tissue.