NEW APPROACHES IN THE DIAGNOSTIC OF ICHTHYOSIS DISORDERS

The aim of this study was to study the macroscopic changes in the skin of patients with various forms of ichthyosis to improve and optimize treatment. A comprehensive examination of 12 patients with ichthyosis under the supervision of a dermatovenereologist was conducted at VOKSHVD. For the diagnosis of macroscopic skin changes, the dermatoscopy was performed by the HEINE DELTA 20 ® (Germany) apparatus, the results were recorded with a Canon 550D camera (Japan) at 1:35 or 1:30, with a sensitivity of IZO 200 using an adapter included with the dermatoscope. All affected skin were examined, which were compared with unharmed ones. The task was performed using the algorithm developed by us for dermatoscopic assessment of the severity of ichthyosis. The presence of typical dermatoscopic signs in examined patients with ichthyosis, which is manifested by the smoothness of the skin pattern, the presence of a pseudo-pigmental mesh, formed by keratin of scales in the form of lines, mesh and loop structures resembling cerebriform components, are established. The algorithm of estimation of expressiveness of dermatoscopic features for patients with light and severe clinical course of ichthyosis is proposed. Also, specific dermatological signs were observed in the mild clinical course of ichthyosis, in particular the phenomenon of «sparkling champagne», and in severe clinical course, the «melting ice» phenomal. The use of the dermatoscopic method makes it possible to objectively evaluate the severity of the ichthyosis and apply a differentiated approach to choosing the most effective treatment schemes.

[New classification and genetic background of inherited ichthyoses]

A new classification of inherited ichthyoses is presented based on clinical features, genetic background and pathophysiology. Ichthyoses are disorders of cornification and may be part of syndromes. Ichthyosis vulgaris, X-linked ichthyosis, autosomal recessive congenital ichthyosis and syndrome-related variants are described. Severe forms can be potentially life-threatening. Dry scaly skin can be disabling and time-consuming, as the patient needs topical therapy and sometimes also systemic retinoids. Treatment today is symptomatic, but hopefully new knowledge will lead to targeted therapies.

Inherited ichthyoses/generalized Mendelian disorders of cornification

Inherited ichthyoses, defined as the generalized form of Mendelian disorders of cornification, are characterized by visible scaling and/or hyperkeratosis of most or all of the skin. This etiologically and phenotypically heterogenous group of conditions is caused by mutations in various different genes important for keratinocyte differentiation and epidermal barrier function. Diagnosing a specific entity is a particular challenge for the nonspecialist presented with the common clinical scaling. For the clinician, this review outlines an algorithmic approach for utilizing diagnostic clues to narrow down the differential diagnosis and to guide further testing and treatment options.

Updated molecular genetics and pathogenesis of ichthiyoses

Research into the molecular genetics and pathomechanisms of ichthyoses have advanced considerably, resulting in the identification of several causative genes and molecules underlying the disease. In 2009, the First Ichthyosis Consensus Conference was held to establish a consensus for the nomenclature and classification of inherited ichthyoses, by which an international consensus for the classification of inherited ichthyosis was achieved. In this review, the pathogeneses of various ichthyoses are summarized based on their revised classification and terminology. Skin barrier defects are involved in the pathogenesis of various types of ichthyosis. The known causative molecules underlying ichthyosis include ABCA12, lipoxygenase-3, 12R-lipoxygenase, CYP4F22, ichthyin and steroid sulfatase, all of which are thought to be related to the intercellular lipid layers. ABCA12 is a known keratinocyte lipid transporter associated with lipid transport in lamellar granules and a loss of ABCA12 function leads to defective lipid transport in the keratinocytes, resulting in the most severe, harlequin ichthyosis phenotype. Other causative molecules for ichthyoses are transglutaminase 1, keratins and filaggrin. Transglutaminase 1 plays a role in cornified cell envelope formation. Keratins 1, 10 and 2 are involved in the keratin network of suprabasal keratinocytes and filaggrin is essential for the formation of keratohyalin granules. It is important to obtain information concerning genetic defects and to elucidate ichthyotic disease pathomechanisms for the establishment of an effective therapy and beneficial genetic counseling, including a prenatal diagnosis for families affected by ichthyotic disease.

[Unraveling the ichthyosis types]

Ichthyoses are hereditary and sometimes acquired diseases of keratinisation. They are heterogeneous according to their clinical and histopathological presentations, as well as to the nature of their molecular and genetic alterations. We present the most frequent types of hereditary ichthyoses.

Pleomorphic ichthyosis: proposed name for a heterogeneous group of congenital ichthyoses with phenotypic shifting and mild residual scaling

Congenital ichthyosis is often associated with typical neonatal phenotypes, "Collodion baby" and "Harlequin foetus", later transforming into severe lamellar or erythrodermic ichthyosis. However, in a minority of cases the skin condition will improve spontaneously after birth, although slight scaling, xerosis, hypohidrosis and keratoderma usually persist. Some of these patients will eventually be diagnosed as suffering from self-improving collodion ichthyosis, ichthyosis prematurity syndrome, or other, even rarer, forms of ichthyosis also characterized by a phenotypic shift in early childhood. This paper summarizes newly described aetiologies for some of these diseases and discusses difficulties encountered when trying to distinguish them clinically from other types of autosomal recessive congenital ichthyosis. To remind health providers about this heterogeneous group of partially transient disorders of cornification, a new umbrella term, "pleomorphic ichthyosis", is proposed.

Generalized peeling skin syndrome: Case report and review of the literature

Peeling skin syndrome (PSS) is a rare form of ichthyosis with a probable autosomal recessive inheritance that exhibits superficial, painless, continual, or seasonal cutaneous exfoliation. The syndrome generally appears at birth or in infancy. We report a case of generalized PSS and provide a literature review. A 34-year-old woman reported a lifelong history of generalized and painless peeling of the skin that worsened in summer. Her parents were third degree cousins. Her twin sister and her two cousins presented with the same condition. Physical examination showed widespread superficial sheets of variable size that could be easily removed without bleeding or pain. No underlying erythema was noted. Otherwise, the patient was in good health. Histological findings showed an epidermal cleavage within the stratum corneum. The generalized form of PSS is classified into 3 types, A, B, and C, according to the classification system of Traupe and Mevorah. We have tried to classify the cases of generalized PSS already reported in the literature into one of these three types. Thirteen reported cases probably presented PSS-type A. Sixteen patients are best described as PSS-type B. Two patients exhibit PSS-type C. Fifteen reported patients had an acral form of peeling skin syndrome. The classification of the eleven remaining patients was difficult to determine. Our patient presented clinical and histological features of generalized PSS-type A.

Ichthyosis: clinical manifestations and practical treatment options

Ichthyoses constitute a large group of cornification disorders that affect the entire integument. The skin is characterized by visible scaling and in many cases by inflammation, for example, in bullous/keratinopathic ichthyosis or Netherton syndrome. From the viewpoint of classification it is useful to distinguish non-syndromic from syndromic types of ichthyosis. Ichthyosis vulgaris and recessive X-linked ichthyosis are common disorders - often of delayed onset, in contrast to congenital ichthyoses, which belong to the group of rare diseases and present at birth with either the features of collodion membrane or congenital ichthyosiform erythroderma. The diagnostic steps are based on clinical data, analyses such as the steroid sulfatase activity test, skin biopsies, and genetic results. However, the dramatic increase in knowledge about the pathophysiology of these conditions has not led to a curative therapy so far. The therapeutic management is multidisciplinary and involves ichthyosis patient organizations in many countries. The mainstay of treatment remains with moisturizing creams containing, for example, urea, lactic acid and other humectants and keratolytics, regular bathing, and mechanical scale removal. Patients with lamellar ichthyosis or ichthyosiform erythroderma in particular profit from oral therapy with retinoids or retinoic acid metabolism-blocking agents.

The development and initial validation of the Liverpool sicca index to assess symptoms and dysfunction in patients with primary Sjögren's syndrome

BACKGROUND

A validated measure to assess sicca-related symptoms in patients with primary Sjögren's syndrome (1 degrees SS) is required for clinical studies.

METHODS

A self-administered questionnaire was developed to assess sicca-related symptoms and dysfunction in 1 degrees SS. This was administered to three groups of 40 respondents to measure construct validity: 1 degrees SS patients, non-SS patients reporting xerostomia and a non-patient group. The frequency of scores and the mean score for each question were calculated for each group. Reliability was assessed by test/retest.

RESULTS

The measure consisted of 28 items divided into five domains. Scores for questions in domains were generally worse (higher) for 1 degrees SS patients than for patients with xerostomia. The non-patient group reported the best (lowest) scores for all questions. The Kappa statistic for all but four questions was greater than 0.6, suggesting good reliability.

CONCLUSION

Questionnaire showed good construct validity and reliability. The Liverpool sicca index needs to be further validated in larger, multicentre studies.

[Between factoids and facts, between dry skin and rough skin]

The concept of dry skin as supported by cosmetologists and the layman is inadequate. This misnomer entails diverse physiopathologic disorders sharing an abnormal and uneven retention of corneocytes. The term xerosis is more appropriate to cope with such a definition. Treatments aim at removing the corneocytes in excess by opening the corneodesmosomes. A topical supplementation in hydrating and emollient agents is beneficial. The application of lipids similar to those normally present in the intercellular space also shows efficacy.

[Acquired peeling skin syndrome in an adult]

BACKGROUND

Peeling skin syndrome is a rare form of congenital ichthyosis. The term was coined in 1982 by Levy and Goldsmith and the syndrome is clinically characterized by generalized scaling. Histologically, there is an epidermal separation in the stratum corneum.

CASE REPORT

We report the case of a 73-year-old woman who had ichthyosis without cicatricial progressive alopecia since her first pregnancy. An ultrastructural study was performed confirming the clinical diagnosis of peeling skin syndrome.

DISCUSSION

The peeling skin syndrome designates several different clinical entities classed by Traupe in type A and type B. Mevorah and al. expanded this classification with a type C. This classification has remained valid after additional information provided by ultrastructural studies and may suggest different pathogenic mechanisms underlying the dermatosis. A critical review of the literature shows that the case reported here is exceptional and had a late clinical onset.

Ichthyosis congenita type IV: a new case resembling diffuse cutaneous mastocytosis

The wide phenotypical heterogeneity within the ichthyosis congenita group of diseases is well known. We report a case of a very rare and unusual autosomal recessive ichthyosis congenita, type IV, according to the ultrastructural classification. Our case presented the triad clue for the diagnosis, characterized by follicular hyperkeratosis, prematurity and perinatal complications, but the clinical diagnosis was further complicated by hypereosinophilia and a strongly positive Darier's sign suggesting diffuse cutaneous mastocytosis. The diagnosis was provided only by electron microscopy, which showed the pathognomonic markers of ichthyosis congenita type IV, namely a large number of membrane structures in the stratum corneum and stratum granulosum. As a consequence, correct genetic counselling for the parents was carried out, and they were informed about the benign course of the disease after the complications of the perinatal period. This case is a further example of the reliability of ultrastructural markers in the diagnosis of inherited keratinization disorders, especially those with an unusual clinical appearance.

Keratitis, ichthyosis, and deafness (KID syndrome): review of the literature and proposal of a new terminology

The so-called KID (keratitis, ichthyosis, deafness) syndrome is a congenital disorder of ectoderm that affects not only the epidermis, but also other ectodermal tissues such as the corneal epithelium and the inner ear. Sixty-one patients who fulfill the criteria for this syndrome were identified in a review of the literature through December 1993. All had cutaneous and auditory abnormalities, and 95% also had ophthalmologic defects. The most frequent clinical features were neurosensory deafness 90%, erythrokeratoderma 89%, vascularizing keratitis 79%, alopecia 79%, and reticulated hyperkeratosis of the palms and soles 41%. All of these findings constitute the major criteria for the diagnosis. The KID acronym does not accurately define this entity since the disorder is not an ichthyosis, because scaling is not the main cutaneous feature and not all patients have keratitis early in the course. We suggest that this syndrome should be included under the general heading of congenital ectodermal defects as a keratodermatous ectodermal dysplasia (KED).

Ichthyosiform dermatosis with superficial blister formation and peeling: evidence for a desmosomal anomaly and altered epidermal vitamin A metabolism

We describe a man with generalized congenital ichthyosiform dermatosis, severe cheilitis, and palmar and plantar hyperkeratosis with superficial blistering. Low-dose acitretin therapy induced areas of peeling skin, similar to that seen in the peeling skin syndrome. Histologically, the skin was moderately hyperkeratotic and the palmar blisters were subcorneal. Electron microscopy revealed that the splitting occurred within the desmosomal plaque. Ultrastructural and biochemical investigations indicated epidermal hypervitaminosis A, probably related to alteration of epidermal retinoic acid metabolism. This disease is proposed as a hitherto unreported variant of the peeling skin syndrome.

A particular subtype of ichthyosis congenita type III. Clinical, light, and electron microscopic features

We report the case of a second patient with the extraordinary ultrastructural findings of vacuolated structures intermingled with membranes in the perinuclear part of the upper epidermal cells. Clinical, light microscopic, and electron microscopic features of this particular presentation of ichthyosis congenita type III have already been presented by K. M. Niemi and L. Kanerva in 1989. Although our patient has more or less the same light and electron microscopic findings, the clinical picture is more severe. The patient was born as a collodion baby. Later, he showed signs of generalized severe involvement with large scales, erythrodermia, and itching. Successful therapy with retinoids resulted in complete removal of the hyperkeratosis but left the striking reticulate skin pattern. Noting the heterogeneous clinical presentation, the specific electron microscopic findings are diagnostic. No biochemical data on this disease are known.

[The collodion baby. Nosographic assessment and description of 2 clinical cases]

Newborns with clinically evident forms of congenital ichthyosis are generally classified as "collodion babies" in view of the particular appearance of their skin that looks rather like a membrane of dried cellophane. This is an extremely rare clinical picture that may be the expression of various types of ichthyosis. The present paper describes two cases of collodion baby with a report on the latest discoveries about the physiopathology of the condition and the current classification of its congenital forms.

Molecular heterogeneity of steroid sulfatase deficiency: a multicenter study on 57 unrelated patients, at DNA and protein levels

Steroid sulfatase (STS) deficiency is the biochemical defect of X-linked ichthyosis (XLI), one of the most common X-linked disorders. We studied 57 European unrelated patients affected by STS deficiency. Twenty-eight patients were from Italy, 24 from the United Kingdom, 4 from The Netherlands, and 1 from Denmark. In two families XLI was associated with Kallmann syndrome (hypogonadotropic hypogonadism and anosmia). STS enzymatic activity was profoundly deficient in all cases. Direct DNA analysis, using cDNA and genomic probes from the STS gene and linked regions, demonstrated heterogeneity of the molecular defect. Forty-eight patients (84%) showed a deletion of the STS gene. In 44 cases the deletion also involved the STS flanking locus DXS237. In 1 patient a partial deletion of the STS gene was detected and in 9 patients no evidence of deletion was found. Locus DXS31 (probe M1A), previously mapped to Xp22.3-pter, was not deleted either in 24 patients with X-linked ichthyosis or in two families with X-linked ichthyosis associated with Kallmann syndrome. Consequently, the following loci order could be suggested: telomere--DXS31--(DXS237, STS)--Kallmann--centromere. Immunoblotting experiments, performed using anti-STS polyclonal antibodies, revealed the absence of cross-reacting material to STS in all cases tested, including 4 patients without evidence of deletions.

Simplified method of determination of serum cholesterol sulfate by reverse phase thin-layer chromatography

A new method for determination of cholesterol sulfate (CS) and dehydroepiandrosterone sulfate (DHEAS) from 1 ml serum by reverse phase thin-layer chromatography (TLC) is described. The method comprises an isolation step of sulfated steroids by means of octadecylsilane-bonded (C18) reverse phase column chromatography, a solvolysis step for desulfation of sulfated steroids, and a C18 TLC step for measurement on a photodensitometer. This method is much simpler and more rapid than the methods previously reported, since neither a radioisotope is needed, nor any steps of saponification, derivatization, tedious scraping from a TLC plate, and time-consuming conventional column chromatography are not required. The present method allowed us to distinguish recessive X-linked ichthyosis (RXLI) very easily from ichthyosis vulgaris (IV) by the size and gradation of clearly visible blue chromogen derived from CS on a TLC plate in RXLI. By photodensitometer scanning, the CS levels in patients with RXLI were about 10 times higher than those of patients with IV and healthy subjects, whereas the DHEAS level was normal in the RXLI patients. The present simplified method proved to be useful in diagnosis of RXLI.

Trichodysplasia-xeroderma: an autosomal dominant condition

We describe six generations of a family with an autosomal dominant condition combining different degrees of trichodysplasia and xeroderma.

Genetically transmitted, generalized disorders of cornification. The ichthyoses

In this review, we have attempted to classify the genetically transmitted, generalized disorders of cornification according to available genetic, clinical, and biochemical data (Table 1). Admittedly, the list is long and sure to be lengthened, but this manner of delineation is required to uncover the underlying biochemical causes of the DOC. Grouping diseases according to artificial and outmoded standards clearly impedes this effort, as well as undermines a scholarly approach to patients, because important information about disease expression, differences in inheritance patterns, and subtle, but important, differences in responsiveness to therapy may be obscured by classification of an entity on the basis of overly simplified diagnostic criteria. Thus, clinicians should be wary of classification schemes based solely upon phenotypic similarities, because they may not be based upon valid genetic or biochemical criteria. Clearly, the classification offered in this article must be considered provisional, and it should be modified as new information is acquired. Despite our desire to recognize and codify distinct genetic disorders, this has not been possible in all cases, such as in DOC 17 (chondrodysplasia punctata syndromes), which almost certainly includes more than one genetic entity.

The biologic basis of the ichthyoses

The ichthyoses, a heterogeneous group of disorders characterized by scaling, have become an unexpectedly rich source of information on normal epidermal biology and cell cohesion and dishesion. In spite of recent success with systemic retinoid therapy, the ichthyoses remain a challenging problem concerning treatment. Nosology and classification are unfinished, and the analysis of biochemical abnormalities promises a refinement in diagnosis.

The ichthyoses--pathogenesis and prenatal diagnosis: a review of recent advances

Disturbances in the process of normal cornification leading to pathologic scaling provide the pathophysiologic basis for the ichthyoses. These disturbances may result from either abnormalities in protein metabolism (keratinization) (i.e., the "bricks") or in lipid metabolism (i.e., the "mortar") (Fig. 1). The evidence linking the various ichthyoses to defects in protein or lipid metabolism have been reviewed. It is likely that future advances will lead not only to a more complete understanding of the pathogenesis of these disorders, but also will shed significant light on the normal stratum corneum functions of barrier formation and desquamation, as well as lead the way to more rational and effective therapies. In recent years, prenatal diagnosis has been successfully performed in several of the ichthyoses. It is likely that improvements in our ability to prenatally diagnose those disorders will advance hand-in-hand with further progress in unraveling their underlying causes.

[Cicatricial ectropion and lamellar icthyosis (author's transl)]

The authors describe the surgical procedure employed in a case of bilateral cicatricial ectropion (superior and inferior), occurring during the course of a lamellar icthyosis. Total skin homografts should be applied before the appearance of severe corneal lésions on both eyelids, inferior and then superior. Two factors have to be emphasized: the apparent appearance of rejection of the grafts when the first dressings are made, and the progressive retraction of the homografts which requires repeated graft applications.