Spectrum of ichthyoses in an Austrian ichthyosis cohort from 2004 to 2017

Blocking of IL-4/IL-13 Signalling With Dupilumab Results in Restoration of Serum and Cutaneous Abnormalities in Netherton Syndrome

Netherton syndrome (NS) is a rare ichthyosis caused by SPINK5-null mutations, resulting in erythroderma, ichthyosis linearis circumflexa, and atopic diathesis. Elevated serum IgE levels and activation of the KLK5-PAR2-TSLP axis suggest involvement of Th2-skewed immunity in NS. In this pilot study, we investigated the effects of IL-4/IL-13 blocking with dupilumab on NS features. At baseline, Th2-chemokines CCL11, CCL17, CCL18, CCL26, and serum IgE were more elevated in atopic dermatitis (AD) than in NS vs. controls (ctrls). AD exhibited elevated serum levels of CCL27, LDH, and eosinophils, while NS showed higher levels of IL-9 and IL-18. Epidermal aberrations, including acanthosis and SC-detachment, were present in NS versus ctrls. The number of CD3+ T cells increased, while CD1a + Langerhans cell numbers decreased in NS skin. Amounts of KLK5 were reduced, and the distribution of KLK7 was abnormal in NS epidermis as compared to ctrls. Reduced amounts of FLG, CDSN, and DSG1 highlight impaired keratinocyte late differentiation in NS. Amounts of epidermal TSLP were diminished. Upon dupilumab treatment, clinical improvement in NS began as early as week 8 and continued up to 30 months, with no serious side effects reported. Serum levels of IgE, CCL17, CCL26, IFN-γ and IL-18 decreased upon IL-4/IL-13 blockade, and alterations of cutaneous immune cells improved in NS. Furthermore, the epidermal protease inhibitor WFDC12 expression increased after dupilumab treatment, concurring with improved and partially normalised epidermal structure, including increased FLG, CDSN, and DSG1. These data highlight Th2-skewed immunity in NS and emphasise the amelioration of NS features through dupilumab treatment.

Molecular analysis of inherited disorders of cornification in polish patients show novel variants and functional data and provokes questions on the significance of secondary findings

BACKGROUND

The Mendelian Disorders of Cornification (MeDOC) comprise a large number of disorders that present with either localised (palmoplantar keratoderma, PPK) or generalised (ichthyoses) signs. The MeDOC are highly heterogenic in terms of genetics and phenotype. Consequently, diagnostic process is challenging and before implementation of the next generation sequencing, was mostly symptomatic, not causal, which limited research on those diseases. The aim of the study was to genetically characterise a cohort of 265 Polish patients with MeDOC and to get insight into the skin lesions using transcriptome and lipid profile analyses.

RESULTS

We detected causal variants in 85% (226/265) patients. In addition to the primary gene defect, a pathogenic variant in another gene involved in MeDOC pathology was identified in 23 cases. We found 150 distinct variants in 33 genes, including 32 novel and 16 recurrent (present in > 5 alleles). In 43 alleles large rearrangements were detected, including deletions in the STS, SPINK5, CERS3 and recurrent duplication of exons 10-14 in TGM1. The RNA analysis using samples collected from 18 MeDOC patients and 22 controls identified 1377 differentially expressed genes - DEG. The gene ontology analysis revealed that 114 biological processes were upregulated in the MeDOC group, including i.e. epithelial cell differentiation, lipid metabolic process; homeostasis; regulation of water loss via skin; peptide cross-linking. The DEG between TGM1 and ALOX12B patients, showed that RNA profile is highly similar, though fatty acid profile in epidermal scrapings of those patients showed differences e.g. for the very long chain fatty acids (VLCFAs; FAs ≥ C20), the very long-chain monounsaturated fatty acids (VLC-MUFAs, FAs ≥ C20:1) and the n6 polyunsaturated fatty acids (n6 PUFAs).

CONCLUSION

Our results show that NGS-based analysis is an effective MeDOC diagnostic tool. The Polish MeDOC patients are heterogenic, however recurrent variants are present. The novel variants and high number of TGM1 and SPINK5 copy number variations give further insight into molecular pathology of MeDOC. We show that secondary variants in MeDOC-related genes are present in a significant group of patients, which should be further investigated in the context of phenotype modifiers. Finally, we provide novel RNA and lipid data that characterise molecularly MeDOC epidermis.

Case report of self-improving collodion ichthyosis in the newborn

Self-improving collodion ichthyosis (SICI) is a relatively rare subtype of autosomal recessive congenital ichthyosis (ARCI) that is often characterized by a collodion baby (CB) phenotype at birth. A newborn girl, just 1 hour old, presented with taut, shiny, thick yellow crusts, like parchment, and scales on her trunk and upper limbs. The tightening effect had caused both upper eyelids to appear everted, and her lips and auricles were deformed. Based on whole-exome sequencing and examination of the clinical phenotype, the patient was diagnosed with ARCI. After admission, the exposed mucosa was covered with a sterile Vaseline gauze dressing, and she was placed in an incubator set to a temperature of 32°C with a humidity level of 75%. One week later, the parchment-like scales had begun to flake off, and at the age of 3 weeks, all bodily skin appeared normal. SICI was diagnosed. After discharge, the patient was followed up to 3 months of age, at which time her growth and development were comparable to those of her peers. Clinicians should consider SICI as a possible diagnosis when analyzing the prognosis of patients with CB. Reducing water loss and maintaining the electrolyte balance are particularly important for SICI treatment.

Ichthyosis vulgaris: An updated review

Ichthyosis vulgaris is an inherited, non-syndromic form of ichthyosis that presents with skin problems. Making up more than 95% cases of ichthyosis, ichthyosis vulgaris is caused by heterozygous loss-of-function mutation of the filaggrin gene, raising the fragility and permeability of the stratum corneum. It typically presents in infancy as xerosis, skin lesions, keratosis pilaris, palmoplantar hyper linearity, scaly dermatosis, and erythroderma, clearly identifiable by age 5. Although majority of patients have a normal lifespan, possible complications include a vitamin D deficiency and auditory problems due to scaling in the ears, besides a drop in quality of life due to dermatological changes. Urea-based creams with 10% urea, ceramides, and other ceramides are often the first line therapy in ichthyosis vulgaris. There is no known curative treatment for ichthyosis vulgaris, but lifelong treatment can alleviate the symptoms. Urea-based creams are highly therapeutic, whereas ammonium lactate 12% lotion with a physiological lipid-based repair cream can help with scaling and dryness. There is also evidence in favour of propylene glycol solutions. Risankizumab, an anti-interleukin-23 drug, and enhancement of natural moisturizing factors are also two highly promising solutions that require additional research. This review aims to provide updates on the manifestation, evaluation, and treatment of ichthyosis vulgaris.

Congenital Ichthyosis: Clinical and Genetic Characteristics of the Disease

Congenital ichthyosis is a group (almost 100 clinical variants) of rare genetic skin diseases caused by pathogenic changes in more than 50 genes. Clinical features of ichthyosis, regardless of its genotype, are dry skin, peeling, hyperkeratosis frequently accompanied with erythroderma. These patients have extremely low quality of life due to changes in appearance, discomfort due to itching and functional limitations (pain during walking, impaired hands motor skills and functions due to hyperkeratosis foci in functionally relevant areas), as well as impaired functions of various organs and systems in syndromic forms of disease. Patients need daily skin care and systemic medications. By now, there is no definitive treatment for ichthyosis. Diagnostic difficulties in determining the clinical forms of congenital ichthyosis are associated with their clinical heterogeneity and with similarity in external manifestations. Difficulties in differential diagnosis with other dermatoses are particularly crucial in case of syndromic forms of disease. This review presents the modern classification of ichthyoses, provides data on disease clinical and genetic variants, diagnostic algorithms, treatment methods for patients with this severe disease.

Randbetonte erythematöse Plaques bei einem Patienten mit kongenitaler Ichthyose: von häufigen und seltenen Dermatosen

Nicht-syndromale autosomal-rezessive kongenitale Ichthyosen (ARCI) sind seltene hereditäre Verhornungsstörungen mit einem heterogenen Spektrum an Phänotypen von einer nahezu erscheinungsfreien Haut über eine milde bis schwere Erythrodermie bis hin zu Panzer-artigen Schuppen. Zu den Hauptvertretern zählen die lamelläre Ichthyose, die kongenitale ichthyosiforme Erythrodermie, die Harlekin-Ichythose, die „bathing suit ichthyosis“ und die „self-improving congenital ichthyosis“ (SICI), die sich im Laufe des ersten Lebensjahres bessert und im späteren Leben nur noch durch eine Xerosis cutis mit diskreten, feinen weißen Schuppen äußert.

Wir berichten über einen 38-jährigen Patienten, der sich mit einer milden kongenitalen Ichthyose unbekannter genetischer Ursache und einem seit einem Monat erheblich verschlechterten Hautbefund vorstellte. Anhand des klinischen Befundes mit anulären, randbetonten, schuppenden erythematösen Plaques, der Histologie und einer Schuppenpilzkultur konnte eine durch Trichophyton rubrum hervorgerufene Tinea corporis als Ursache für die Exazerbation identifiziert werden. Diese heilte nach 4-wöchiger systemischer Therapie mit Terbinafin komplett ab. Zurück blieb nur eine Xerosis cutis mit einer feinen weißen Schuppung. Passend zur klinischen Verdachtsdiagnose einer SICI erbrachte die molekulargenetische Untersuchung zwei mutmaßlich compound-heterozygote, wahrscheinlich pathogene Varianten im ALOXE3-Gen, eine Spleiß-Variante (c.1392+2T>A;p.?) und ein komplexes Rearrangement. ALOXE3 kodiert für die Lipooxygenase E3, die für die epidermale Differenzierung und für den Aufbau des „cornified envelope“ bedeutsam ist. Varianten in diesem Gen sind eine der Hauptursachen für SICI.

Patienten mit Ichthyosen weisen aufgrund des verdickten Stratum corneum, einer verzögerten Desquamation, einer gestörten epidermalen Barrierefunktion und einer Störung der Talg- und Schweißproduktion ein erhöhtes Risiko für Dermatophytosen auf. Diese präsentieren sich oft atypisch und können daher leicht verkannt werden. Insbesondere bei schweren kongenitalen Ichthyosen sind chronische Verläufe und Rezidive häufig. Unser Fall zeigt, dass auch und gerade bei Patienten mit seltenen Verhornungsstörungen an häufige infektiöse Dermatosen wie Tinea corporis gedacht werden muss.

Mild Phenotype of Arthrogryposis, Renal Dysfunction, and Cholestasis Syndrome 1 Caused by a Novel VPS33B Variant

The arthrogryposis, renal dysfunction, and cholestasis syndrome (ARCS) is an autosomal recessive multisystem disease caused by variants in VPS33B or VIPAS39. The classical presentation includes congenital joint contractures, renal tubular dysfunction, cholestasis, and early death. Additional features include ichthyosis, central nervous system malformations, platelet dysfunction, and severe failure to thrive. We studied three patients with cholestasis, increased aminotransferases, normal gamma-glutamyl transferase, and developmental and language delay. Whole exome sequencing analysis identified VPS33B variants in all patients: patients 1 and 2 presented a novel homozygous variant at position c.1148T>A. p.(Ile383Asn), and patient 3 was compound heterozygous for the same c.1148T>A. variant, in addition to the c.940-2A>G. variant. ARCS is compatible with the symptomatology presented by the studied patients. However, most patients that have been described in the literature with ARCS had severe failure to thrive and died in the first 6 months of life. The three patients studied here have a mild ARCS phenotype with prolonged survival. Consequently, we believe that the molecular analysis of the VPS33B and VIPAS39 should be considered in patients with normal gamma-glutamyl transferase cholestasis.

Quality of life and clinical characteristics of self-improving congenital ichthyosis within the disease spectrum of autosomal recessive congenital ichthyosis

BACKGROUND

Autosomal recessive congenital ichthyosis (ARCI) is a heterogeneous group of ichthyoses presenting at birth. Self-improving congenital ichthyosis (SICI) is a subtype of ARCI and is diagnosed when skin condition improves remarkably (within years) after birth. So far, there is sparse data on SICI and quality of life (QoL) in this ARCI subtype. This study aims to further delineate the clinical spectrum of SICI as a rather unique subtype of ARCI.

OBJECTIVES

This prospective study included 78 patients (median age: 15 years) with ARCI who were subdivided in SICI (n=18) and non-SICI patients (nSICI, n=60) by their ARCI phenotype.

METHODS

Quality of life (QoL) was assessed using the (Children's) Dermatology Life Quality Index. Statistical analysis was performed with Chi-square- and t-tests.

RESULTS

The genetically confirmed SICI patients presented causative mutations in the following genes: ALOXE3 (8/16; 50.0%), ALOX12B (6/16; 37.5%), PNPLA1 (1/16; 6.3%) and CYP4F22 (1/16; 6.3%). Hypo-/anhidrosis and insufficient Vitamin D levels (< 30 ng/ml) were often seen in SICI patients. Brachydactyly (a shortening of the 4^th and 5^th finger) was statistically more frequent in SICI (p=0.023) than nSICI patients. A kink of the ear's helix was seen in half of the SICI patients and tends to occur more frequently in patients with ALOX12B mutations (p=0.005). QoL was less impaired in patients under the age of 16, regardless of ARCI type.

CONCLUSIONS

SICI is an underestimated, milder clinical variant of ARCI including distinct features such as brachydactyly and kinking of the ears. Clinical experts should be aware of these features when seeing neonates with a collodion membrane. SICI patients should be regularly checked for clinical parameters such as hypo-/anhidrosis or vitamin D levels and monitored for changes in quality of life.

Ichthyosis and hereditary cornification disorders in dogs

The stratum corneum (SC), the outermost layer of the epidermis, serves a crucial role in maintaining body hydration and protection from environmental insults. When the stratum corneum is injured or when the genetic blueprints are flawed, the body is at risk of dehydration, secondary infections and allergen sensitization. Advancements in veterinary dermatology have revealed a wide gamut of disease from relatively benign to lethal that specifically arise from flawed structural proteins, enzymes or lipids needed to create the corneocytes and lipid bilayers of the SC. Some conditions closely mimic their human counterparts while others are unique to the dog. This review will focus on forms of ichthyosis in the dog.

High rate of self-improving phenotypes in children with non-syndromic congenital ichthyosis: case series from south-western Germany

BACKGROUND

Non-syndromic congenital ichthyosis describes a heterogeneous group of hereditary skin disorders associated with erythroderma and scaling at birth. Although both severe and mild courses are known, the prediction of the natural history in clinical practice may be challenging.

OBJECTIVES

To determine clinical course and genotype-phenotype correlations in children affected by non-syndromic congenital ichthyosis in a case series from south-western Germany.

METHODS

We performed a retrospective observational study of 32 children affected by non-syndromic congenital ichthyoses seen in our genodermatosis clinic between 2011 and 2020. Follow-ups included assessment of weight and severity of skin involvement utilizing a modified Ichthyosis Area Severity Index (mIASI). mIASI was calculated as a sum comprising the previously published IASI score and an additional novel score to evaluate palmoplantar involvement. Linear regression was assessed using Pearson correlation, and statistical analysis was performed using the Wilcoxon-Mann-Whitney test.

RESULTS

This study included 23 patients with autosomal recessive congenital ichthyosis, seven with keratinopathic ichthyosis and two with harlequin ichthyosis. Cutaneous manifestations improved in more than 70% of the children during the follow-up. Especially in patients with mutations in ALOXE3 and ALOX12B, mIASI scores dropped significantly. The most common phenotype observed in this study was designated 'mild fine scaling ichthyosis'. Severe palmoplantar involvement occurred in patients with KRT1 and ABCA12 mutations; most patients demonstrated hyperlinearity as a sign of dryness and scaling. Weight was mainly in the normal range and negatively correlated with the severity of skin involvement.

CONCLUSIONS

Congenital ichthyosis that self-improves and evolves with mild fine scaling ichthyosis was the most common phenotype observed in our patients. This type might be underdiagnosed if the genetic diagnosis is not performed in the first year of life. mIASI is an easy and fast instrument for scoring disease severity and adding additional points for palmoplantar involvement might be valuable.

Novel Homozygous Mutations in the Genes TGM1, SULT2B1, SPINK5 and FLG in Four Families Underlying Congenital Ichthyosis

Background: Ichthyoses are a large group of hereditary cornification disorders, which are both clinically and etiologically heterogeneous and affect mostly all the skin surface of the patients. Ichthyosis has its origin in an ancient Greek word “ichthys” meaning fish, this is because the ichthyosis patients have dry, thickened, and scaly skin. There is an excess accumulation of epidermal cells resulting in the appearance of continuous and widespread scales on the body. There are many varieties of ichthyosis with a broad spectrum of intensity, severity, and associated symptoms, most of them are extremely rare. Ichthyosis vulgaris is the most frequently occurring type of ichthyoses. Method: The present study consists of four Pakistani ichthyosis families (A, B, C, and D). Whole exome sequencing (WES) approach was used to identify the pathogenic sequence variants in probands. The segregation of these variants in other participants was confirmed by Sanger sequencing. Results: Total four variants including, two splice site (TGM1: c.2088 + 1G > A) and (SPINK5: c.882 + 1G > T), a missense (SULT2B1: c.419C > T; p. Ala140Val), and a nonsense (FLG: c.6109C > T; p. Arg2037Ter) variant were identified in families A, C, B, and D, respectively, as causative mutations responsible for ichthyosis in these families. Conclusion: Our study unravels the molecular etiology of the four Pakistani ichthyosis families and validates the involvement of TGM1, SULT2B1, SPINK5, and FLG, in the etiology of different forms of ichthyosis. In addition, this study also aims to give a detailed clinical report of the studied ichthyosis families.

Developmental cell programs are co-opted in inflammatory skin disease

The skin confers biophysical and immunological protection through a complex cellular network established early in embryonic development. We profiled the transcriptomes of more than 500,000 single cells from developing human fetal skin, healthy adult skin, and adult skin with atopic dermatitis and psoriasis. We leveraged these datasets to compare cell states across development, homeostasis, and disease. Our analysis revealed an enrichment of innate immune cells in skin during the first trimester and clonal expansion of disease-associated lymphocytes in atopic dermatitis and psoriasis. We uncovered and validated in situ a reemergence of prenatal vascular endothelial cell and macrophage cellular programs in atopic dermatitis and psoriasis lesional skin. These data illustrate the dynamism of cutaneous immunity and provide opportunities for targeting pathological developmental programs in inflammatory skin diseases.