黑头粉刺的扫描电镜观察

用扫描电镜观察27例寻常性座疮的黑头粉刺,它主要有排列致密的角化细胞、皮脂、细菌和抱子所组成.2例群聚性眶周黑头粉刺和1例黑头粉刺状痣的黑头粉刺只见疏松排列的角化细胞,未见细菌和抱子.我们推测皮脂醋留、座疮杆菌和卵圆皮屑芽抱菌在寻常性座疮的发病上起重要作用.     

Keratoacanthoma arising in nevus comedonicus

Nevus comedonicus is a benign hamartoma of the pilosebaceous unit and is considered as a rare subtype of epidermal nevus. It was first described in 1895. It manifests as a group of closely dilated follicular openings with dark keratin plugs resembling comedones. Malignant degeneration of a nevus comedonicus is exceptional; we report a case of keratoacanthoma arising in extensive nevus comedonicus.     

Nevus comedonicus

The nevus comedonicus (NC) is an uncommon variant of adnexal hamartoma which appears clinically as linear groups of open comedones. Its name may be a misnomer since, according to some, true comedones are not present. NC usually occurs by itself but may be linked with a variety of systemic findings such as skeletal or ocular anomalies. Although the nevus comedonicus is viewed by many as a hamartoma arising from a defective mesoderm, others consider this lesion to be an epidermal nevus involving the hair follicle or an appendageal nevus of sweat ducts.     

Disseminated congenital comedones

A 3-month-old boy with congenital and extensive skin comedones without any other extracutaneous manifestations is reported. This patient does not fit with other reported disorders of congenital or childhood extensive comedones, such as nevus comedonicus, familial dyskeratotic comedones, idiopathic disseminated comedones, childhood flexural comedones, and acne neonatorum.     

Nevus Comedonicus Syndrome: A New Pediatric Case

Abstract: Nevus comedonicus (NC) is an uncommon developmental defect of the pilosebaceous apparatus. The individual lesions are large comedones often arranged in groups or in a linear pattern. Nevus comedonicus syndrome (NCS) is a well-defined disorder within the large group of epidermal nevus syndromes. In patients suffering from NCS, the nevus is associated with noncutaneous abnormalities including skeletal defects, cerebral anomalies, and cataracts. We report a 9-year-old boy with open comedones in a linear pattern localized to the right cheek, clinodactyly and Polydactyly of the first right finger, bilateral syndactyly of the second and third toes, and some depigmented hairs since birth.     

A 5-year-old boy with comedo-like lesions on the right buttock

A healthy, 5-year-old boy presented with cutaneous lesions on the right buttock, evident at birth. A physical examination revealed plugged pores in a linear distribution with the appearance of comedones and scar areas. Histopathological exam revealed multiple atrophic cystically dilated hair follicles containing abundant keratinous debris and small projections of epithelial cells extending from the wall of the cyst into the surrounding dermis, compatible with nevus comedonicus.     

Nevus Comedonicus in Oral‐Facial‐Digital Syndrome Type 1: A New Finding or Overlapping Syndromes?

We report a patient with oral‐facial‐digital syndrome type 1 (OFDS1) who exhibited features overlapping those of nevus comedonicus syndrome, an unusual presentation that may potentially represent a new variant of OFDS1. OFDS1 and nevus comedonicus syndrome represent two rare syndromes with numerous overlapping features that have yet to be described in relation to one another. The features present in our patient led us to propose the possibility of a new variant of OFDS1 in which nevus comedonicus represents a cutaneous manifestation of the syndrome. Knowledge of this potential relationship is important for identification and management of the syndromes' accompanying manifestations in affected patients and may offer further insight into crossroads of pathogenesis.     

The Nevus Comedonicus Syndrome: A case Report with Emphasis on Associated Internal Manifestations

A 14-year-old boy with nevus comedonicus, multiple congenital abnormalities of the spine, and a central nervous system disorder is described. The associated abnormalities previously reported with nevus comedonicus are summarized. Thorough evaluation of patients with nevus comedonicus may disclose the occurrence of certain internal abnormalities in syndromic association.     

Nevus comedonicus with epidermolytic hyperkeratosis

A 7-year-old girl had a linear nevus comedonicus affecting the right upper limb. Histologic examination of two biopsies specimens showed both the common changes of nevus comedonicus and the presence of epidermolytic hyperkeratosis. Therefore, nevus comedonicus should be included in the list of dermatoses having the distinctive histologic pattern of epidermolytic hyperkeratosis.     

FGFR2 signaling and the pathogenesis of acne

Acne in Apert syndrome and unilateral segmental acneiform nevus are associated with mutations of fibroblast growth factor receptor 2 (FGFR2), which are likely to be involved in the pathogenesis of acne. Translational animal and cellular models, developmental biology studies and clinical observations have contributed to our understanding of FGF‐FGFR2 signaling in the pilosebaceous follicle. The importance of FGF‐FGFR2 signaling in mesenchymal‐epithelial interaction for skin appendage formation, pilosebaceous follicle homeostasis, come‐dogenesis and sebaceous gland proliferation is explored. Overstimulation of FGFR2 signaling with increased expression of interleukin‐1α explains acne in Apert syndrome und nevus comedonicus. Androgen‐mediated up‐regulation of FGFR2 signaling could be the initiating signal in the pathogenesis of acne. The gain of function FGFR2 mutations in Apert syndrome and unilateral acneiform nevus are most helpful model diseases for uncovering the fundamental process of androgen‐dependent mesenchymal‐epithelial FGF‐FGFR2 signaling in acne in Apert syndrome, nevus comedonicus and acne vulgaris.     

Nevus comedonicus with hidradenoma papilliferum and syringocystadenoma papilliferum in the female genital area

Background Nevus comedonicus is an uncommon malformation of the pilosebaceous unit. Association of nevus comedonicus with tumors originating from the apocrine gland has not previously been reported. Method We present a case of nevus comedonicus associated with hidradenoma papilliferum (HAP) and syringocystadenoma papilliferum (SCAP) in the female genital area. Results Histological features strongly suggested nevus comedonicus associated with HAP and SCAP. Conclusion Although the association of nevus comedonicus with HAP and SCAP is very rare, the possibility of coexistence cannot be excluded.     

Nevus comedonicus syndrome

BACKGROUND: Nevus comedonicus is a rare disease and diagnosis is made chiefly on clinical grounds. It may occur in isolation, or in rare cases, it may be combined with other congenital malformations to constitute nevus comedonicus syndrome. We report a case of this disease herein. PATIENTS AND METHODS: A young woman aged 20 years presented with cribriform plaques since birth resulting from the juxtaposition of depressed pigmented scars and comedonic lesions. These lesions were found on the entire face, the left hemithorax and the left upper limb, with well delineated distribution stopping at the median line. The patient's history revealed congenital cataract of the left eye operated at the age of 10 years. Clinical diagnosis of nevus comedonicus was confirmed by histological examination of the skin. Laboratory screening for other associated malformations revealed no abnormalities. Oral retinoids were proposed but the patient refused all treatments. DISCUSSION: Nevus comedonicus is one of the rarest forms of cutaneous nevus. This case is original as regards the extent and topography of the nevus covering the left side of the patient's body and its association with congenital cataract potentially indicating nevus comedonicus syndrome. This syndrome is extremely rare and belongs to a large group of epidermal nevus syndromes characterised by association of nevus and extracutaneous malformations, particularly ocular, skeletal and neurological.     

IL-17 downregulates filaggrin and affects keratinocyte expression of genes associated with cellular adhesion

Atopic eczema and psoriasis are common skin diseases. While it is well established that the pathogenesis of these diseases varies, both are characterized by impairment in epidermal barrier function and abnormal IL-17 expression in the skin and peripheral blood. Recent findings indicated that filaggrin is essential during barrier formation and its insufficiency underlies the pathogenesis of atopic eczema. Filaggrin downregulation has also been reported in psoriasis. It is clear that Th1/Th2 bias influences expression of the protein, but an analysis of the effects of interleukin-17 (IL-17) on the expression of the protein and profilaggrin-processing enzymes has not yet been reported. In addition, the effect of the cytokine on components of functional epidermal barrier, tight junctions and adhesion/desmosomal proteins, has not been elucidated. Keratinocytes were exposed to interleukin-17A, and microarray analysis was performed. Filaggrin protein level was assessed by western blot. We have observed a significant decrease in profilaggrin mRNA level in interleukin-17A-exposed cultures (P = 0.008). Expression of processing enzymes was also altered, indicating an indirect effect of the cytokine on filaggrin production/degradation. Moreover, expression of many genes involved in cellular adhesion was also decreased. A significant downregulation of filaggrin at the protein level was detected by western blot in immortal and primary keratinocytes. Gene ontology analysis indicated changes in keratinization, epidermal differentiation and formation of the cornified envelope. We conclude that IL-17A downregulates the expression of filaggrin and genes important for cellular adhesion which could affect epidermal barrier formation. This effect potentially contributes to barrier dysfunction and could become a possible therapeutic target.     

Nevus Comedonicus Syndrome—Nevus Comedonicus Associated with Ipsilateral Polysyndactyly and Bilateral Oligodontia

Abstract: A 7‐year‐old boy diagnosed as a case of nevus comedonicus syndrome is presented because of the rarity of the condition and the association of the previously unreported features oligodontia and unilateral polysyndactyly restricted to the same side as the nevus comedonicus.     

Characterization of two monoclonal antibodies to human epidermal keratohyalin: reactivity with filaggrin and related proteins

Two monoclonal antibodies (AKH1 and AKH2) were elicited with partially purified human filaggrin and characterized by immunohistochemistry on normal and abnormal skin biopsies, immunoblotting techniques, and antigen purification. Both antibodies react strongly with the granular cell layer consistent with the distribution of keratohyalin and show a more diffuse reaction with the stratum corneum in normal skin biopsies. Reaction in cultured human keratinocytes is limited to immunofluorescent granules in flattened, well-differentiated cells in confluent cultures, in which we have previously demonstrated keratohyalin. On immunoblots AKH1 reacts with filaggrin (37 kD) and profilaggrin (400 kD), while AKH2 primarily stains bands of 150 and 300 kD. The AKH2 antigens were identified in the cationic protein fraction used for immunization and were purified by gel permeation and high-performance liquid chromatography. Amino acid composition of these proteins differs only slightly from filaggrin. Immunohistochemical staining patterns of the two antibodies are very similar in the genetic disorders of keratinization tested, except for ichthyosis vulgaris, and reflect the presence and distribution of keratohyalin. In ichthyosis vulgaris, AKH1 staining is weak, consistent with the morphology and with biochemical absence of profilaggrin/filaggrin; however, AKH2 staining is positive, although weaker than normal, suggesting the presence of the AKH2 antigens even when keratohyalin is absent or abnormal. Antibodies AKH1 and AKH2 may be useful as differentiation markers for keratinization in tissues and for cells in culture. Antibody AKH1 can be used specifically for detection of profilaggrin/filaggrin in tissues, cultured keratinocytes, and extracts.     

Immunoelectron microscopy links molecules and morphology in the studies of keratinization

It is impossible to understand keratinization disorders without knowing what is going on at molecular levels. We and others have been analyzing the issues of keratinization by means of (immuno)electron microscopy and found that this is quite a useful tool for molecular pathology. We summarize the recent advances in the biology and pathology of keratinization at ultrastructural and molecular levels. Tonofilaments, a morphological hallmark of keratinocytes, are composed of keratins. Epidermolytic hyperkeratosis, a genetic disease of keratin K1/K10, shows clumped tonofilaments that are shown to be actually composed of K1/K10 by immunoelectron microscopy. Distribution of profilaggrin and its derivatives has also been revealed by immunoelectron microscopy. Defective interaction between keratin and filaggrin is seen in epidermolytic hyperkeratosis. Transient nuclear localization of N-terminal domains of profilaggrin is observed in the transitional cells of normal epidermis. Unique distribution of trichohyalin was detected in psoriasis. Distribution of various components of cornified cell envelopes including involucrin and loricrin in normal and abnormal keratinization can also be detected with this technique. Premature formation of involucrin-rich cell envelopes are observed in psoriasis vulgaris. Defects in cross-linking of loricrin are detected in transglutaminase 1 knockout mice, the animal model of lamellar ichthyosis. Abnormal distribution of loricrin has been detected in genetic diseases of loricrin (loricrin keratoderma). By combining immunoelectron microscopy and terminal deoxynucleotidyl transferase-mediated dUDP nick-end labeling (TUNEL) methods, the nature of TUNEL positive cells has also been unravelled.     

Nevus Comedonicus: A Case Series

Twelve previously unreported cases of nevus comedonicus are presented. Characteristic closely grouped dilated follicular openings with horny plugs that mimic comedones led to the diagnosis. One patient had nevus comedonicus syndrome and there were cases with atypical locations and unusual complications of this condition. We also highlight clinical associations and therapeutic options.     

Extensive inflammatory nevus comedonicus involving half of the body

Nevus comedonicus is an uncommon variant of adnexal hamartoma without known cause. It usually occurs on the face, neck and chest and appears as groups of closely arranged dilated follicular openings with keratin plugs. We report extensive inflammatory nevus comedonicus in a 14-year-old boy involving half of his body, limited by the midline, with suppuration and residual scarring. The lesions first appeared at 3 years of age and worsened at the start of puberty. The clinical features, etiopathology, histopathology and treatment options of nevus comedonicus are briefly reviewed in the light of the literature.     

Epidermal nevus syndrome and didymosis aplasticosebacea

Abstract:  The epidermal nevus syndrome is a disease complex consisting of the association of an epidermal nevus with various developmental abnormalities of the skin, eyes, nervous, skeletal, cardiovascular, and urogenital systems. The epidermal nevi are classified according to their predominant component; nevus sebaceus (sebaceous glands), nevus comedonicus (hair follicles), and nevus verrucosus (keratinocytes). We report a neonate who presented with a nevus sebaceus on the scalp and face as well as a coloboma and dermoid on his left eye. Within the sebaceous nevus on the scalp, circumscribed lesions of aplasia cutis congenita were detected, which is consistent with the recently proposed term in the literature didymosis aplasticosebacea.