Disorders of keratinization: diagnosis and management

Skin Tape Stripping Reveals Distinct Biomarker Profiles in Chronic Hand Eczema of Patients With and Without Comorbid Atopic Dermatitis

INTRODUCTION

Chronic hand eczema (CHE) is a highly prevalent inflammatory skin condition which is often resistant to conventional treatments. Molecular insights of CHE remain limited. Tape stripping combined with high-throughput RNA sequencing can now provide a better insight into CHE pathogenesis in a minimally invasive fashion.

METHODS

We collected tape strip samples from lesional and non-lesional skin of 66 patients with moderate-to-severe CHE, comprising 33 with and 33 without comorbid atopic dermatitis (AD), and performed bulk RNA sequencing. Results were compared to tape strips from palmar skin of age/race/sex-matched healthy controls (HC). Differentially expressed genes (DEGs) (fold change/FCH > 1.5 and false discovery rate/FDR < 0.05) were calculated and correlated with clinical severity scores including hand eczema severity index (HECSI) and modified total lesion symptoms score (mTLSS).

RESULTS

Tape strip isolates detected a common phenotype in CHE lesions regardless of AD status, including upregulated type-1 (IL12RB2, IFNGR1, IFNGR2, MX1) and type-2-associated inflammatory mediators (CCL22, CCL24, OX40/TNFRSF4, TSLPR/CRLF2, GATA3), paralleled by downregulated epidermal barrier markers (i.e., FLG or LORICRIN). Non-lesional skin demonstrated a similar, albeit milder, dysregulation pattern, with additional reduction in type-17 pathways. Lesional skin of CHE patients without AD showed greater skewing towards type-1 immunity (IL15RA, CXCL9), while CHE from AD patients showed a more pronounced type-2 inflammatory pattern (IL13, CCL17) and their gene expression biomarkers had greater and more significant correlations with clinical severity markers.

CONCLUSION

Tape stripping can capture detailed immune and skin barrier abnormalities in CHE and identify potential novel subtype-specific treatment targets. Stronger correlations in patients with AD suggest a more homogenous disease phenotype than in CHE non-AD patients.

TRIAL REGISTRATION

NCT03728504.

Revisiting X-linked congenital ichthyosis

X-linked recessive ichthyosis (XLI) is a hereditary skin disease characterized by generalized dryness and scaling of the skin, with frequent extracutaneous manifestations. It is the second most common type of ichthyosis, with a prevalence of 1/6,000 to 1/2,000 in males and without any racial or geographical differences. The causative gene for XLI is the steroid sulfatase gene (STS), located on Xp22.3. STS deficiency causes an abnormal cholesterol sulfate (CS) accumulation in the stratum corneum (SC). Excess CS induces epidermal permeability barrier dysfunction and scaling abnormalities. This review summarizes XLI's genetic, clinical, and pathological features, pathogenesis, diagnosis and differential diagnoses, and therapeutic perspectives. Further understanding the role of the STS gene pathogenic variants in XLI may contribute to a more accurate and efficient clinical diagnosis of XLI and provide novel strategies for its treatment and prenatal diagnosis.

Advances in the treatment of autosomal recessive congenital ichthyosis, a look towards the repositioning of drugs

Autosomal recessive congenital ichthyoses (ARCI) are a skin pathology due to genetic causes characterized by a variable degree of desquamation, accompanied by erythema. The degree of symptoms is variable, different altered genes are involved, and the symptoms drastically affect patients' quality of life. Topical treatments are a first-choice strategy due to their ease of application and cost; however, enteral administration of retinoids offers greater efficacy, although with certain limitations. Despite the treatment alternatives, ARCI will persist throughout life, disabling people. Therefore, the search for new treatments always remains necessary. Especially repositioning drugs could be a short-term alternative to new affordable treatments for patients. Taking advantage of extensive knowledge of known drugs or biologics could ensure more accessible and possibly lower-cost treatments. This review briefly and concisely addresses possible repositioning strategies with drugs and biologics for ichthyosis.

New developments in the molecular treatment of ichthyosis: review of the literature

Ichthyosis covers a wide spectrum of diseases affecting the cornification of the skin. In recent years, new advances in understanding the pathophysiology of ichthyosis have been made. This knowledge, combined with constant development of pathogenesis-based therapies, such as protein replacement therapy and gene therapy, are rather promising for patients with inherited skin diseases. Several ongoing trials are investigating the potency of these new approaches and various studies have already been published. Furthermore, a lot of case series report that biological therapeutics are effective treatment options, mainly for Netherton syndrome and autosomal recessive congenital ichthyosis. It is expected that some of these new therapies will prove their efficacy and will be incorporated in the treatment of ichthyosis.

Effectiveness of saline water and lidocaine injection treatment of intractable plantar keratoma: a randomised feasibility study

Background

An intractable plantar keratoma (IPK) is a conical thickening of the epidermis’ stratum corneum and a common cause of foot pain which can have a significant, detrimental impact on the mobility, quality of life and independence of individuals. Conservative treatments are currently offered to patients with IPK, but they are unsatisfactory since they do not offer a sufficient or permanent reduction of symptoms. The purpose of this study was the evaluation of the feasibility, safety and effectiveness of innovative treatments for intractable plantar keratoma (IPK).

Methods

A randomized single blind trial with 40 patients divided with block randomization in four parallel groups was conducted to compare treatment combinations: conservative sharp debridement only or sharp debridement with needle insertion, physiological water injection or lidocaine injection. All patients obtained the same treatment four times at a four-week interval. At each visit, visual analog scale (VAS), Foot Function Index (FFI) and IPK size were evaluated. VAS and FFI were also completed at a six and twelve-month follow-up.

Results

Our findings in regards to feasibility demonstrated recruitment challenges because of the anticipated pain that would be provoked by needle insertion may not be worth the potential pain relief compared to debridement alone from the patient’s perspective. This was also the principal cause of drop out. Our preliminary results show no main effect of group for any of the clinical outcomes: pain felt on VAS, FFI score, IPK’s size (p > 0.05). However, the analysis revealed a statistically significant effect of time on VAS (p < 0.001), FFI score (p < 0.001) and IPK’s size (width and depth (p < 0.001); length (p = 0.001)), but no group x time interaction was found (p > 0.05).

Conclusions

This study demonstrates that IPK treatment consisting of sharp debridement with needle insertion, physiological saline water injection or lidocaine injection is feasible and safe. There was a non-statistically significant trend toward diminishing pain intensity compared to scalpel debridement alone. The pain provoked by needle insertion and injection treatments must be addressed with a scientifically proven protocol to make it more comfortable for patients before these treatments could be considered in further studies.

Trial registration

ClinicalTrials.gov, NCT04777227. 2 March, 2021 - Retrospectively registered (All participants were recruited prior to registration).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-021-00467-7.

The Junctional Epithelium Is Maintained by a Stem Cell Population

The most fundamental function of an epithelial tissue is to act as a barrier, regulating interactions between the external environment and the body. This barrier function typically requires a contiguous cell layer but since teeth penetrate the oral epithelium, a modified barrier has evolved, called the junctional epithelium (JE). In health, the JE attaches to the tooth, sealing the inside of the body against oral micro-organisms. Breakdown of the JE barrier results in periodontal ligament (PDL) disintegration, alveolar bone resorption, and ultimately tooth loss. Using lineage tracing and DNA pulse-chase analyses, we identified an anatomical location in the JE that supported both fast- and slow-cycling Wnt-responsive stem cells that contributed to self-renewal of the tissue. Stem cells produced daughter cells with an extraordinarily high rate of turnover that maintained JE integrity for 1.4 y in mice. Blocking cell proliferation via a chemotherapeutic agent 5-fluorouracil (5-Fu) eliminated fast-cycling stem cells, which caused JE degeneration, PDL destruction, and bone resorption. Upon removal of 5-Fu, slow-cycling stem cells regenerated both the structure and barrier function of the JE. Taken together, our studies identified a stem cell population in the JE and have potential clinical implications for prevention and treatment of periodontitis.

Hereditary Palmoplantar Keratoderma: A Practical Approach to the Diagnosis

The ridged skin of the palms and soles has several unique features: (i) presence of dermatoglyphics created by alternating ridges and grooves forming a unique pattern, (ii) presence of the highest density of eccrine sweat glands and absence of pilosebaceous units, and (iii) differential expression of keratins compared to the glabrous skin. These features explain the preferential localization of palmoplantar keratoderma (PPK) and several of its characteristic clinical features. PPK develops as a compensatory hyperproliferation of the epidermis and excessive production of stratum corneum in response to altered cornification of the palmoplantar skin due to mutations in the genes encoding several of the proteins involved in it. PPK can manifest as diffuse, focal, striate, or punctate forms per se or as a feature of several dermatological or systemic diseases. There is a wide genetic and phenotypic heterogeneity in hereditary PPK, due to which reaching an accurate diagnosis only on the basis of clinical features may be sometimes challenging for the clinicians in the absence of molecular studies. Nevertheless, recognizing the clinical patterns of keratoderma, extent of involvement, degree of mutilation, and associated appendageal and systemic involvement may help in delineating different forms. Molecular studies, despite high cost, are imperative for accurate classification, recognizing clinical patterns in resource poor settings is important for appropriate diagnosis, genetic counseling, and management. This review intends to develop a practical approach for clinical diagnosis of different types of hereditary PPK with reasonable accuracy.

Management of congenital ichthyoses: European guidelines of care, part one

These guidelines for the management of congenital ichthyoses have been developed by a multidisciplinary group of European experts following a systematic review of the current literature, an expert conference held in Toulouse in 2016 and a consensus on the discussions. They summarize evidence and expert-based recommendations and are intended to help clinicians with the management of these rare and often complex diseases. These guidelines comprise two sections. This is part one, covering topical therapies, systemic therapies, psychosocial management, communicating the diagnosis and genetic counselling.

Moisturizers: The Slippery Road

Moisturizers are an important part of a dermatologist's armamentarium although little is written and well, a less is truly known about them. There is a cornucopia of projected skin products in the market whose real scientific role is not proven. These products although at times are regarded as mere cosmetics but have a well-known role in many skin disorders. Adequate knowledge about their mechanism of action, dosage, usage, and adverse effects is must for a dermatologist in this era. This article aims to bring forth the ever hidden facts of the much-hyped moisturizers. It is probably the first of its kind covering all aspects of moisturizers ranging from basic science to clinical usage, a subject that receives a short shrift in the current dermatological text.

Myelodysplastic Syndrome Presenting as Amegakaryocytic Thrombocytopenia in a Collodion Baby

We report a rare case of myelodysplastic syndrome that presented early as amegakaryocytic thrombocytopenia in a collodion baby, which is a rare congenital disorder characterized by thick, taut membrane resembling oiled parchment or collodion, which is subsequently shed. To our knowledge, this is the first reported case of a collodion baby who presented with amegakaryocytic thrombocytopenia and who has a significant family history of the same condition. We document the rarity of this possible association and also the need for further study to establish whether a causal relationship exists.

Autosomal recessive congenital ichthyosis

The term autosomal recessive congenital ichthyosis (ARCI) refers to a group of rare disorders of keratinization classified as nonsyndromic forms of ichthyosis. This group was traditionally divided into lamellar ichthyosis (LI) and congenital ichthyosiform erythroderma (CIE) but today it also includes harlequin ichthyosis, self-healing collodion baby, acral self-healing collodion baby, and bathing suit ichthyosis. The combined prevalence of LI and CIE has been estimated at 1 case per 138 000 to 300 000 population. In some countries or regions, such as Norway and the coast of Galicia, the prevalence may be higher due to founder effects. ARCI is genetically highly heterogeneous and has been associated with 6 genes to date: TGM1, ALOXE3, ALOX12B, NIPAL4, CYP4F22, and ABCA12. In this article, we review the current knowledge on ARCI, with a focus on clinical, histological, ultrastructural, genetic, molecular, and treatment-related aspects.

Pacific island 'Awa (Kava) extracts, but not isolated kavalactones, promote proinflammatory responses in model mast cells

Kava ('Awa) is a traditional water-based beverage in Pacific island communities, prepared from the ground root and stems of Piper methysticum. Kava use is associated with an ichthyotic dermatitis and delayed type hypersensitivity reactions. In the current study we collated preparative methodologies from cultural practitioners and recreational kava users in various Pacific communities. We standardized culturally informed aqueous extraction methods and prepared extracts that were subjected to basic physicochemical analysis. Mast cells exposed to these extracts displayed robust intracellular free calcium responses, and concomitant release of proinflammatory mediators. In contrast, mast cells were refractory to single or combinatorial stimulation with kavalactones, including methysticin, dihydromethysticin and kavain. Moreover, we reproduced a traditional modification of the kava preparation methodology, pre-mixing with the mucilage of Hibiscus tiliaceus, and observed its potentiating effect on the activity of aqueous extracts in mast cells. Taken together, these data indicate that water extractable active ingredients may play a role in the physiological and pathophysiological effects of kava, and suggests that mast cell activation may be a mechanistic component of kava-related skin inflammations.

Efficacy of topical 10% urea-based lotion in patients with ichthyosis vulgaris: a two-center, randomized, controlled, single-blind, right-vs.-left study in comparison with standard glycerol-based emollient cream

BACKGROUND

Ichthyoses are genetic disorders of keratinization which are uncomfortable due to their conspicuous scaling, itching and cosmetic problems. Ichthyoses can lead to social discrimination and psychological problems. Ichthyosis vulgaris (IV) is the most common form of these geno-dermatoses. IV is a chronic disorder that often requires continuous therapy. Emollient and keratolytic products are the mainstay treatments of IV. It is important that efficient, safe and well tolerated therapies should be available. Direct comparative data regarding efficacy of different emollient products in IV patients are very few.

OBJECTIVE

The aim of the study was to investigate the keratolytic and moisturizing properties as well as the tolerance of a new urea topical formulation (Ureadin Rx10) when applied to hyperkeratotic and dry skin in patients with (IV) in comparison with a standard emollient cream.

METHODS

The study was conducted as a two-center, randomized, controlled, single-blind, intra-patient (right-vs.-left) trial design. A total of 30 patients with IV between 8 and 65 (mean age: 25 years) treated with a 10% urea-based lotion, Ureadin Rx 10 * *Ureadin RX 10 is a registered trade name of ISDIN, Spain. (URx), for 4 weeks or a glycerol-based emollient cream, Dexeryl † †Dexeryl is a registered trade name of Pierre Fabre Dermatologie. (DC), in a right-vs.-left study design. Primary outcome was a 5-point SRRC Index score (evaluating scaling roughness, redness and cracks) evaluated at baseline and after 2 and 4 weeks of treatment. As secondary endpoints patients evaluated also the global efficacy (GE) and global tolerability (GT) scores with the help of a 10 cm visual analogue scale (0 = no efficacy at all/very bad tolerability; 10: excellent efficacy/excellent tolerability).

RESULTS

At baseline the mean (SD) SRRC score was 9.5 (1.9) in the URx treated sites and 9.5 (1.9) in the DC treated sites. A total of 27 patients (90%) concluded the study period. Three patients were withdrawn prematurely because of itching and burning sensation after DC application (1 patient) or URx application (2 patients). At week 4, in comparison with baseline values, both treatments were shown to be clinically effective: SRRC significantly (p = 0.0001) decreased to 3.3 (1.8) after URx (a 65% relative reduction) and to 5.7 (2.5) after DC (a 40% relative reduction). SRRC was significantly lower in URx treated regions in comparison with DC both after 2 and 4 weeks of treatment (p = 0.0005). Mean GE score in areas treated with URx was significantly (p = 0.0001) higher than in the areas treated with the DC (8.9 vs.7.3). Both treatments were in general well tolerated. GT score was 8.1 (range 10 to 3) with URx and 8.4 (range 10 to 3) with DC application (p = ns). The two main limitations of this trial are the study design (single blind), and the small sample size which is not adequate for an evaluation of safety.

CONCLUSION

Ureadin Rx 10 lotion has shown a greater efficacy on ichthyosis vulgaris in term of reduction of scaling, roughness, redness and cracking in comparison with a glycerol-based emollient cream. Tolerability of the two topical treatments was comparable. Further studies with larger sample sizes are needed for the evaluation of safety and tolerability of urea 10% lotion in this clinical setting.

Association of glycerol and paraffin in the treatment of ichthyosis in children: an international, multicentric, randomized, controlled, double-blind study

BACKGROUND

Efficacy and tolerance should be considered in topical treatments of chronicle affections with impaired skin barrier function such as ichthyosis.

OBJECTIVES

To demonstrate the efficacy of Dexeryl in reducing severity of ichthyosis.

METHODS

A prospective, multicentre, randomized, placebo controlled study was performed with patients under 18 years suffering from a non-bullous form of ichthyosis. A double-blind period using Dexeryl (an emollient cream containing glycerol 15% and paraffin 10%) or placebo (its vehicle) during 4 weeks followed by an open label period with all patients treated by Dexeryl for 8 weeks. Improvement of ichthyosis was assessed by cutaneous xerosis evolution (SRRC score): the percentage of patients with 50% reduction of the SRRC score at D28 was the primary criterion. The assessment of pruritus [visual analogue scale (VAS)], global evaluation and safety were secondary.

RESULTS

The percentage of patients with at least 50% reduction of SRRC score at D28 was significantly higher in Dexeryl group (60.3%) vs. vehicle group (43.5%; P = 0.008). Reduction of pruritus on VAS was significantly higher at D28 with Dexeryl (-2.16) compared to that in placebo (-1.49), P < 0.05. The improvement continues through the open label period: at D84 we observed -2.5 of SRRC score in the Dexeryl group vs.-1.8 for the group previously treated by vehicle. Investigators found Dexeryl efficacy as satisfying for about 80% of treated patients vs. 50% with vehicle. Concerning safety, most of the adverse events were not related to treatment.

CONCLUSIONS

Dexeryl showed a significant improvement of xerosis and related symptoms in children with ichthyosis and was well tolerated.

Revised nomenclature and classification of inherited ichthyoses: results of the First Ichthyosis Consensus Conference in Sorèze 2009

BACKGROUND

Inherited ichthyoses belong to a large, clinically and etiologically heterogeneous group of mendelian disorders of cornification, typically involving the entire integument. Over the recent years, much progress has been made defining their molecular causes. However, there is no internationally accepted classification and terminology.

OBJECTIVE

We sought to establish a consensus for the nomenclature and classification of inherited ichthyoses.

METHODS

The classification project started at the First World Conference on Ichthyosis in 2007. A large international network of expert clinicians, skin pathologists, and geneticists entertained an interactive dialogue over 2 years, eventually leading to the First Ichthyosis Consensus Conference held in Sorèze, France, on January 23 and 24, 2009, where subcommittees on different issues proposed terminology that was debated until consensus was reached.

RESULTS

It was agreed that currently the nosology should remain clinically based. "Syndromic" versus "nonsyndromic" forms provide a useful major subdivision. Several clinical terms and controversial disease names have been redefined: eg, the group caused by keratin mutations is referred to by the umbrella term, "keratinopathic ichthyosis"-under which are included epidermolytic ichthyosis, superficial epidermolytic ichthyosis, and ichthyosis Curth-Macklin. "Autosomal recessive congenital ichthyosis" is proposed as an umbrella term for the harlequin ichthyosis, lamellar ichthyosis, and the congenital ichthyosiform erythroderma group.

LIMITATIONS

As more becomes known about these diseases in the future, modifications will be needed.

CONCLUSION

We have achieved an international consensus for the classification of inherited ichthyosis that should be useful for all clinicians and can serve as reference point for future research.

Annual direct and indirect health costs of the congenital ichthyoses

The aim of this study is to estimate annual, per patient, health care costs for congenital ichthyoses (CI). We conducted a cost analysis through an online survey posted on the Foundation for Ichthyosis and Related Skin Types Website. We assessed cutaneous disease severity, via the previously validated Congenital Ichthyosis Severity Index (CISI), demographics, and CI type. We estimated direct health care costs: prescription and over-the-counter medications, outpatient visits, and emergency department and hospital visit costs; and indirect costs: earnings lost owing to absences from work because of CI-related illness. The CI subjects of our study (n=224) consumed a mean (SD) of $3,192 ($7,915) annually. Direct costs accounted for 90%, whereas indirect costs accounted for 10%. These costs resulted in an estimated annual cost of $37 MM/year (excluding ichthyosis vulgaris) of which $17 MM is borne out-of-pocket by patients. Depending on the CI diagnosis, patients were responsible for 30-51 cents of every dollar of mean annual medical care costs. Our estimated annual CI costs are comparable to cutaneous lymphoma. More effective treatments for CI would help minimize this burden. Traditional insurance products do not appear to substantially alleviate the financial burden of disease, as a significant amount is from out-of-pocket expenses.

X-linked ichthyosis: an oculocutaneous genodermatosis

X-linked ichthyosis (XLI) is an X-linked recessive disorder of cutaneous keratinization with possible extracutaneous manifestations. It was first described as a distinct type of ichthyosis in 1965. XLI is caused by a deficiency in steroid sulfatase activity, which results in abnormal desquamation and a retention hyperkeratosis. XLI is usually evident during the first few weeks of life as polygonal, loosely adherent translucent scales in a generalized distribution that desquamate widely. These are quickly replaced by large, dark brown, tightly adherent scales occurring primarily symmetrically on the extensor surfaces and the side of the trunk. In addition, extracutaneous manifestations such as corneal opacities, cryptorchidism, and abnormalities related to contiguous gene syndromes may be observed. Diagnosis of XLI is usually made clinically, as the histopathology is nonspecific, but confirmation may be obtained through either biochemical or genetic analysis. Treatment should focus on cutaneous hydration, lubrication, and keratolysis and includes topical moisturizers and topical retinoids.

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.

Acute percutaneous lactic acid poisoning in a child

Percutaneous poisoning is quite rare, and in particular, topical lactic acid poisoning is even more so. We report a young girl with lamellar ichthyosis and symptoms of poisoning, with clinical signs of irritability, agitation, myoclonia, and difficulty in walking, accompanied by lactic acidosis as a result of the more frequent than recommended application of emollients containing lactic acid. The clinical symptoms resolved upon discontinuation of the topical treatment. Among the possible causes of metabolic acidosis, health care providers should be aware of the possibility of percutaneous poisoning.

Cutaneous manifestations in celiac disease

Celiac disease (CD) is an autoimmune gluten-dependent enteropathy characterized by atrophy of intestinal villi that improves after gluten-free diet (GFD). CD is often associated with extra-intestinal manifestations; among them, several skin diseases are described in CD patients. The present review reports all CD-associated skin manifestations described in the literature and tries to analyze the possible mechanisms involved in this association. The opportunity to evaluate the possible presence of CD in patients affected by skin disorders is discussed.

[Incontinentia pigmenti in a five-week-old girl]

Shortly after birth, a five-week-old female infant developed small blisters and erythema that followed the lines of Blaschko on the upper and lower extremities as well as the abdomen. Histological examination confirmed the clinical presumptive diagnosis of incontinentia pigmenti. We discuss the dinical features, diagnosis, and the molecular genetic basis of this rare inherited skin disorder.

Neonatal skin barrier: structure, function, and disorders

The development of the human skin from intrauterine to extrauterine life is a balletic interplay of maturing layers and interlocking structures. We discuss this transition and then branch out to touch on issues of premature infant as well as neonatal skin care. Disruption of the barrier function due to toxins and development errors are expounded upon. Staph scalded skin syndrome, collodion membrane, bullous congenital ichthyosiform erythroderma, autosomal recessive ichthyosis (lamellar and congenital ichthyosiform erythroderma), and harlequin fetus are used as examples of these disruptions. Discussion of therapy with the authors' experience highlights each disease.