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Acne vulgaris is a common neutrophil-driven inflammatory skin disorder in which Cutibacterium acnes (C. acnes) plays a significant role. For decades antibiotics have been widely used to treat acne vulgaris, with the inevitable increase in bacterial antibiotic resistance.Phage therapy is a promising solution to the rising problem of antibiotic-resistant bacteria, utilizing viruses that specifically lyse bacteria.Here, we explored the feasibility of phage therapy against C. acnes. Combining eight novel phages we had isolated and commonly used antibiotics, 100% of clinically isolated C. acnes strains were eradicated.Using topical phage therapy in a C. acnes-induced acne-like lesions mouse model resulted in significantly superior clinical and histological scores. Moreover, the inflammatory response decreased as reflected by reducing the chemokine CXCL2, infiltration of neutrophils, and other inflammatory cytokines, compared to the untreated group.These results demonstrate the potential of phage therapy in acne vulgaris treatment, especially when antibiotic-resistant strains are involved.

Acral peeling skin syndrome is a rare genodermatosis characterized by asymptomatic peeling of the acral skin. It is usually caused by biallelic mutations in the gene TGM5. However, biallelic mutations in the CSTA gene have also been described to cause APSS with exfoliative ichthyosis, so far in only five pedigrees. Here, we report two new pedigrees, each with one patient having APSS, due to a novel CSTA mutation.

Summary Capping protein regulator and myosin 1 linker 2 (CARMIL2) deficiency is characterized by impaired T cell activation, which is attributed to defective CD28-mediated co-signaling. Herein, we aimed to analyze the effect of exogenous interleukin (IL)-2 on in-vitro T cell activation and proliferation in a family with CARMIL2 deficiency. This study included four children (one male and three females; aged 2·5–10 years at presentation). The patients presented with inflammatory bowel disease and recurrent viral infections. Genetic analysis revealed a novel homozygous 25-base pairs deletion in CARMIL2. Immunoblotting demonstrated the absence of CARMIL2 protein in all four patients and confirmed the diagnosis of CARMIL2 deficiency. T cells were activated in-vitro with the addition of IL-2 in different concentrations. CD25 and interferon (IFN)-γ levels were measured after 48 h and 5 days of activation. CD25 surface expression on activated CD8+ and CD4+ T cells was significantly diminished in all patients compared to healthy controls. Additionally, CD8+ T cells from all patients demonstrated significantly reduced IFN-γ production. When cells derived from CARMIL2-deficient patients were treated with IL-2, CD25 and IFN-γ production increased in a dose-dependent manner. T cell proliferation, as measured by Cell Trace Violet, was impaired in one patient and it was also rescued with IL-2. In conclusion, we found that IL-2 rescued T cell activation and proliferation in CARMIL2-deficient patients. Thus, IL-2 should be further studied as a potential therapeutic modality for these patients.

SUMMARYAcne vulgaris is a common neutrophile-driven inflammatory skin disorder in whichCutibacterium acnes(C. acnes) bacteria play a significant role. Until now, antibiotics have been widely used to treat acne vulgaris, with the inevitable increase in bacterial antibiotic resistance. Phage therapy is a promising solution to the rising problem of antibiotic-resistant bacteria, utilizing viruses that specifically lyse bacteria.Here, we explored the feasibility of phage therapy againstC. acnes. By combining eight novel phages we had isolated, together with commonly used antibiotics, we achieved 100% eradication of clinically isolatedC. acnesstrains. Using topical phage therapy in an acne mouse model resulted in significantly superior clinical scores, as well as a reduction in neutrophil infiltration compared to the control group. These results demonstrate the potential of phage therapy in acne vulgaris treatment, especially when antibiotic-resistant strains are involved.

We present three children who presented with papules and plaques over the knuckles, mimicking Gottron's papules of juvenile dermatomyositis, as well as subcutaneous nodules over the joints of the extremities that were initially thought to represent calcinosis cutis. However, thorough clinical and laboratory evaluation, as well as imaging, failed to support this diagnosis. Skin biopsies were consistent with a diagnosis of subcutaneous granuloma annulare. This unique phenotype of granuloma annulare should be recognized in order to prevent erroneous diagnosis and treatment.

Vascular anomalies (VAs) may be associated with significant morbidity and mortality. The aim of this study was to evaluate the efficacy and safety of sirolimus (rapamycin) in the treatment of children and young adults with complicated VAs. A retrospective chart was created that included 19 patients treated with sirolimus for complicated VAs. Concurrently, a search of the PubMed database for VA cases treated with sirolimus was conducted. Descriptive analysis was performed and the efficiency rate of sirolimus was calculated. This retrospective study included 19 patients, 17 of whom were treated with oral sirolimus and 2 with topical sirolimus. Clinical improvement occurred in 15 patients (79%). One patient experienced near-complete resolution. Only 2 patients showed poor response and discontinued treatment. The literature review analysed 150 cases of VA treated with sirolimus. Sirolimus was efficient in 85% of cases, including 5 cases of complete resolution. Sirolimus appears to be an effective and safe treatment for children and young adults with complicated VAs.

Signal transducer and activator of transcription (STAT)1 heterozygous gain-of-function (GOF) mutations are known to induce immune dysregulation and chronic mucocutaneous candidiasis (CMCC). Previous reports suggest an association between demodicosis and STAT1 GOF. However, immune characterization of these patients is lacking. Here, we present a retrospective analysis of patients with immune dysregulation and STAT1 GOF who presented with facial and ocular demodicosis. In-depth immune phenotyping and functional studies were used to characterize the patients. We identified five patients (three males) from two non-consanguineous Jewish families. The mean age at presentation was 11.11 (range = 0.58–24) years. Clinical presentation included CMCC, chronic demodicosis and immune dysregulation in all patients. Whole-exome and Sanger sequencing revealed a novel heterozygous c.1386C>A; p.S462R STAT1 GOF mutation in four of the five patients. Immunophenotyping demonstrated increased phosphorylated signal transducer and activator of transcription in response to interferon-α stimuli in all patients. The patients also exhibited decreased T cell proliferation capacity and low counts of interleukin-17-producing T cells, as well as low forkhead box protein 3+ regulatory T cells. Specific antibody deficiency was noted in one patient. Treatment for demodicosis included topical ivermectin and metronidazole. Demodicosis may indicate an underlying primary immune deficiency and can be found in patients with STAT1 GOF. Thus, the management of patients with chronic demodicosis should include an immunogenetic evaluation.

Autosomal recessive congenital ichthyosis (ARCI) is a rare and heterogeneous skin cornification disorder presenting with generalized scaling and varying degrees of erythema. Clinical manifestations range from lamellar ichthyosis (LI), congenital ichthyosiform erythroderma (CIE) through the most severe form of ARCI, Harlequin ichthyosis (HI). We used homozygosity mapping, whole exome and direct sequencing to delineate the relative distribution of pathogenic variants as well as identify genotype-phenotype correlations in a cohort of 62 Middle Eastern families with ARCI of various ethnic backgrounds. Pathogenic variants were identified in most ARCI-associated genes including TGM1 (21%), CYP4F22 (18%), ALOX12B (14%), ABCA12 (10%), ALOXE3 (6%), NIPAL4 (5%), PNPLA1 (3%), LIPN (2%) and SDR9C7 (2%). In 19% of cases, no mutation was identified. Our cohort revealed a higher prevalence of CYP4F22 and ABCA12 pathogenic variants and a lower prevalence of TGM1 and NIPAL4 variants, as compared to data obtained in other regions of the world. Most variants (89%) in ALOX12B were associated with CIE and were the most common cause of ARCI among patients of Muslim origin (26%). Palmoplantar keratoderma associated with fissures was exclusively a result of pathogenic variants in TGM1. To our knowledge, this is the largest cohort study of ARCI in the Middle Eastern population reported to date. Our data demonstrate the importance of population-tailored mutation screening strategies and shed light upon specific genotype-phenotype correlations.

Despite being the first homolog of the bacterial RecQ helicase to be identified in humans, the function of RECQL1 remains poorly characterized. Furthermore, unlike other members of the human RECQ family of helicases, mutations in RECQL1 have not been associated with a genetic disease. Here, we identify 2 families with a genome instability disorder that we have named RECON (RECql ONe) syndrome, caused by biallelic mutations in the RECQL gene. The affected individuals had short stature, progeroid facial features, a hypoplastic nose, xeroderma, and skin photosensitivity and were homozygous for the same missense mutation in RECQL1 (p.Ala459Ser), located within its zinc binding domain. Biochemical analysis of the mutant RECQL1 protein revealed that the p.A459S missense mutation compromised its ATPase, helicase, and fork restoration activity, while its capacity to promote single-strand DNA annealing was largely unaffected. At the cellular level, this mutation in RECQL1 gave rise to a defect in the ability to repair DNA damage induced by exposure to topoisomerase poisons and a failure of DNA replication to progress efficiently in the presence of abortive topoisomerase lesions. Taken together, RECQL1 is the fourth member of the RecQ family of helicases to be associated with a human genome instability disorder.

Bullous pemphigoid is a common autoimmune blistering disorder, characterized by sub-epidermal bullae formation, that tends to affect older patients. We report on a 78 -year-old male patient suffering from bullous pemphigoid, whose disease persisted despite treatment with potent topical corticosteroids, systemic tetracyclines, prednisone and azathioprine. Recently, omalizumab was reported to be effective in several patients with resistant bullous pemphigoid. Omalizumab is a monoclonal antibody against IgE, approved for the treatment of asthma and chronic urticaria and known for its excellent safety profile. The patient was treated accordingly with omalizumab for his bullous pemphigoid with dramatic and rapid regression of his disease.

TBC regimens are considered as "reduced toxicity" and are increasingly employed in pediatric HSCT. In our center, we commonly use the combination of treosulfan-thiotepa-fludarabine and ATG for pediatric non-malignant diseases. As we often observe acute skin toxicities following this conditioning regimen, we conducted a prospective observational study to describe and characterize these toxicities. Fifteen pediatric patients undergoing HSCT for non-malignant diseases who were treated at Hadassah-Hebrew University Medical Center during 2015 were enrolled. A thorough dermatological assessment was done on days 0, 1, 7, and 14 from treatment initiation and included description of cutaneous reactions, measurement of BSA of affected skin, and response to local treatment. All the fifteen enrolled patients developed some degree of acute skin reaction. Cutaneous manifestations were variable and included erythematous patches in inguinal area and genitalia (80%), in neck and axillae (40%), diffuse hyperpigmentation (73%), erosions in inguinal area and buttock (47%), and xerosis and desquamation (40%). Average affected BSA reached 71.8%. Erosions were more prevalent in children younger than 2 years of age. The eruptions resolved without sequela in all patients and did not necessitate treatment other than topical agents. Observed extracutaneous toxicities included oral mucositis (40%), diarrhea (47%), and elevated liver enzymes (47%). TBC combined with thiotepa is highly toxic to the skin with various cutaneous manifestations. The toxicity resolves with no long-term sequela.

All reported patients with hypomorphic X-linked severe combined immunodeficiency (X-SCID) due to c.664C>T (p.R222C) mutations in the gene (IL2RG) encoding the common γ chain (γc) have presented with opportunistic infections within the first year of life, despite the presence of nearly normal NK and T cell numbers. Reporting five children of one extended family with hemizygous mutations in IL2RG, we explore potential diagnostic clues and extend our comprehension of the functional impact of this mutation. Whole exome sequencing (WES); detailed immune phenotyping; cytokine-induced STAT phosphorylation; B, T, and NK cell activation; and quantification of sjTRECs in five Arab children with c.664C>T (p.R222C) IL2RG mutation. The mean age at clinical presentation with respiratory tract infection or diarrhea was 6.8 (range: 2–12) months. None of the children presented with opportunistic infections. Diagnostic clues were early onset in the first year of life, and a suggestive family history associated with reduced naive CD4 T cells and absent switched memory B cells. Number and phenotype of NK cells and innate-like lymphocytes were normal. The diagnosis was made by WES and corroborated by absent STAT phosphorylation and reduced functional response after IL-2 and IL-21 stimulation. Four patients underwent successful hematopoietic stem cell transplantation. As early diagnosis and treatment are important, a high index of suspicion in the diagnosis of c.664C>T (p.R222C) X-SCID is needed. This requires prompt genetic testing by next generation sequencing in order to avoid unnecessary delays in the definite diagnosis since immunological work up may not be discriminating. Assays directly testing cytokine signaling or cytokine-dependent functions are helpful in confirming the functional impact of the identified hypomorphic variants.

Chronic graft versus host disease (cGVHD) is a complication of allogeneic haematopoietic stem cell transplantation (HSCT). The aim of this study was to clinically characterize childhood cutaneous cGVHD. A retrospective study of children treated with HSCT at 2 tertiary medical centres in Israel between 2011 and 2014 was performed. A total of 112 children were included. Cutaneous cGVHD developed in 18% of subjects. Risk factors were older age, HSCT from peripheral blood and acute lymphoblastic leukaemia. The eruption was lichenoid in 90% of subjects, of whom one-third progressed to sclerosis. Topical treatments were usually sufficient in localized disease. Widespread eruption necessitated phototherapy, extracorporeal photopheresis and/or systemic immunosuppressants. Patients presenting with palmoplantar keratoderma, developed sclerosis. To the best of our knowledge, this is the first study describing childhood cutaneous cGVHD. Lichenoid eruption is the most common cutaneous pattern of cGVHD in children. Sclerotic changes may be associated with prior keratoderma. cGVHD poses a therapeutic challenge and better treatments should be sought.

Heterozygous STAT1 gain-of-function (GOF) mutations result in a combined form of immunodeficiency which is the most common genetic cause of chronic mucocutaneous candidiasis (CMC). We present a pedigree with a GOF mutation in STAT1, manifesting with chronic demodicosis in the form of a facial papulopustular eruption, blepharitis, and chalazion. So far, demodicosis has been described in only one family with STAT1-GOF mutation. We suggest that chronic demodicosis is an under-recognized feature of the immune dysregulation disorder caused by STAT1 gain-of-function mutations.

Background Generalized verrucosis (GV) is a chronic and progressive cutaneous human papillomavirus (HPV) infection resulting in multiple warts and associated with acquired or genetic immune defects. We identified a consanguineous Arab family manifesting GV and recurrent bacterial and viral infections, in association with inflammatory bowel disease (IBD). Objective To identify the mutated gene responsible for GV, recurrent infections and IBD, in this family. Methods Flow cytometry of peripheral blood mononuclear cells was performed, as well as proliferation and cell cycle assays of T cells. Whole exome sequencing was utilized to detect candidate mutated genes, assuming an autosomal recessive mode of inheritance. Skin fibroblasts from a patient, the mother and control were incubated with sorbitol to detect the phosphorylation ability of TAOK2, and a clonogenic assay was performed to assess the survival and proliferative capacity of fibroblasts’ colonies. Results Despite normal immunophenotyping of T and B cells, T cell proliferation upon activation was impaired in a patient compared to a heterozygous family member and a control. Genetic analyses identified a rare homozygous missense variant, c.2098C>T (p.R700C) in the TAOK2 gene, segregating with the disease phenotype in the family. TAOK2 encodes the TAO2 kinase, a mitogen activated protein kinase kinase kinase (MAP3K) in the p38-MAPK cascade. The mutation is predicted to disrupt its normal folding and molecular interaction; however, no impairment was observed in TAOK2 kinase activity toward its downstream target, MEK3/6, in patient's fibroblasts. Despite this normal kinase activity, a noticeably higher survival/proliferation of patient's skin fibroblasts was found. Conclusions A mutation in TAOK2 appears to cause a novel form of primary immunodeficiency, characterized by an impaired T cell proliferation upon activation. This novel cause of GV gives further support to the importance of the p38-MAPK pathway in the immune response against HPV, and possibly also in the pathogenesis of IBD.

Purpose Signal transducer and activator of transcription 3 is a member of a family of proteins involved in the regulation of inflammation, differentiation, proliferation, and survival of cells. Here we describe a 38-year-old male who has experienced gastrointestinal, dermatologic, pulmonary, and malignant manifestations. Methods Whole-exome sequencing, validated by Sanger sequencing, was performed after extensive investigations. Findings Whole-exome sequencing revealed a heterozygous missense mutation in the signal transducer and activator of transcription 3 gene, c.1261G>A (p.G421R). Fluorescence-activated cell sorting analysis of peripheral T lymphocytes revealed low levels of CD4 + CD25 + FoxP3 and CD8 + CD25 + FoxP3 regulatory T cells. After treatment with 2 cycles of tocilizumab, an interleukin-6 receptor antibody, a significant increase in the level of regulatory T cells was observed, accompanied by clinical improvement. Implications This case sheds light on the emerging role of signal transducer and activator of transcription 3 gain-of-function mutation in the pathogenesis of autoimmune diseases, and further addresses the therapeutic role of interleukin-6 blocker treatment in this syndrome.

Herein we report on a 9-year-old girl with recalcitrant prurigo nodularis unresponsive to multiple standard treatments. She was started on dupilumab therapy with rapid improvement in pruritus within 2 weeks and near complete regression of lesions at 3 months. Dupilumab should be considered as an off-label treatment for refractory prurigo nodularis in children.

Uncombable hair syndrome (UHS) is a unique hair shaft disease characterized by frizzy, straw-colored hair, which is resistant to combing and brushing. Familial cases have been described, and recently mutations in genes related to trichohyalin production have been reported as the cause for this condition. UHS usually manifests during early childhood, and gradually resolves at puberty. Herein, we report on a 2-year-old boy whose hair changed to a UHS-like phenotype “overnight” with no apparent trigger. The condition resolved abruptly after 9 months. Genetic analysis revealed a heterozygous variant in the PLCD1 gene, which has been connected to hair development. This case raises the possibility that a genetic cause can lead to a temporary change in hair shaft appearance, possibly after exposure to a yet unknown external trigger.

Background Molluscum contagiosum (MC) is a common skin infection in the pediatric age group. The infection is self-limited and manifests as discrete, umbilicated skin-colored papules on any skin surface of the body. At times, complications such as local dermatitis and swelling, erythema, and pus formation may appear. These signs of inflammation are commonly presumed to represent bacterial infection. Methods This multicenter study was a retrospective analysis of data collected on all patients diagnosed with inflamed lesions secondary to MC and treated at the Hadassah Medical Centers and Shaare Zedek Medical Center in Jerusalem, Israel, from 1/1/2008 to 1/07/2018. Characteristics of children with positive cultures were compared to those with negative cultures and those with contaminants. Results A total of 56 cases were reviewed; the mean age at presentation was 4.6 years. Fever was reported in 12.5%, and 62.5% received systemic antibiotics because of their inflamed MC prior to admission. Fifty-five percent had sterile cultures or cultures growing only contaminants. Only seven had positive cultures with the common cutaneous pathogens. No statistical difference was observed between the patients with pathogenic isolates and patients with sterile or non-pathogenic cultures in terms of demographics, lesion characteristics, inflammatory markers, or length of hospitalization. Conclusion The findings suggest that most cases of suspected MC-related secondary infection can be attributed to inflammation rather than to bacterial infection. However, in some cases, true bacterial infection should be suspected and treated accordingly.

Targeted medications and immunotherapies are being developed to specifically target the pathways involved in tumours. There is limited experience with these new medications and their cutaneous side-effects in the paediatric population. A retrospective study of all paediatric oncological patients treated with targeted therapies and immunotherapies between 1 January 2013 and 1 August 2020 was carried out in 2 haemato-oncological referral centres. A total of 103 children were included in the study. The median (interquartile range) age was 13 years (8.4–16.9), male:female ratio 1.5:1, median (interquartile range) follow-up was 7 months (2–18). Fifty (48%) of the children developed cutaneous adverse events. Treatment was discontinued in only 3 (6%) cases and was altered in only (2%) 1 case due to a cutaneous adverse event. When targeted therapies and immunotherapies for tumours in children are used, there is an increased incidence of cutaneous adverse events. Nevertheless, treatment modification or discontinuation due to cutaneous side-effects is rarely needed.

Hand foot and mouth disease (HFMD) is an acute childhood viral exanthem usually associated with coxsackievirus A16 or enterovirus 71. Atypical HFMD associated with coxsackievirus A6 was reported recently. The aim of the current study was to describe coxsackievirus A6-associated atypical HFMD in a series of 8 toddlers who were referred with idiopathic extensive eruptions. Demographic and clinical characteristics, Reverse transcriptase-real-time PCR (RT-PCR) results for enterovirus and phylogenetic analysis for the coxsackievirus A6 strains were recorded. Morphologically polymorphous (vesicular, erosive, papular, desquamative or purpuric) and extensive eruptions were found. One patient had delayed nail shedding. Enterovirus was positive in all patients. Genotype analysis confirmed coxsackievirus A6 in 6 patients and 5 sequences underwent phylogenetic analysis. This is the first such report in Israeli children. In conclusion, coxsackievirus A6 atypical HFMD should be regarded as a novel childhood viral exanthem. We suggest the term "coxsackievirus A6 polymorphic exanthem" due to the extensive and variable nature of this eruption.

Antibiotic-resistant Cutibacterium acnes has been reported worldwide, but data from Israeli patients with acne is currently lacking. This study evaluated the antibiotic susceptibility of C. acnes, isolated from 50 Israeli patients with acne to commonly prescribed antibiotics, using the Epsilometer test (E-test). Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis, 16S rRNA sequencing and single locus sequence typing (SLST) molecular typing were used to identify and characterize C. acnes. Among 36 strains isolated, phylotype IA1 was most common. Resistance to at least one antibiotic was found in 30.6% of tested strains. Resistance rates were highest for erythromycin (25.0%), followed by doxycycline (19.4%), clindamycin (16.7%), minocycline (11.1%) and tetracycline (8.3%). Significant correlation was found between resistance to multiple antibiotics, with 5.6% of isolates resistant to all antibiotics tested. When reviewing resistances rate worldwide antibiotic resistance was found to be prevalent in Israel. Measures to limit the emergence of antibiotic-resistant strains of Cutibacterium acnes should be taken and alternative treatments should be sought.

Inherited skin disorders that have gender specific expression, are those genodermatoses that involve the sex chromosomes. These include the X-linked genodermatoses (recessive and dominant) and sex chromosome abnormalities. The normal X inactivation (lyonization) which occurs in females and results in functional mosaicism, determines the variable phenotypic expression of the same genetic defect, among genders. In recessive X-linked disorders males are affected, while females may be asymptomatic or present with variable and usually mild phenotype, following a mosaic pattern of distribution. Dominant X-linked disorders are usually lethal in male embryos and are seen almost exclusively in female heterozygotes, usually presenting with Blaschko-linear skin involvement. In this chapter, we will review the various X-linked genodermatoses, as well as the cutaneous features of sex chromosomal abnormalities.

Cutaneous leishmaniasis (CL) is diverse in its clinical presentation but usually demonstrates an erythematous, infiltrated, ulcerated, and crusted papule or nodule in exposed areas of the body. Rare clinical features have been reported including lymphatic dissemination, usually with subcutaneous nodules along lymphatic channels. Herein, we present six patients suffering from Old World CL with lymphatic dissemination characterized by sporotrichoid subcutaneous nodules along the lymphatic channels draining the primary lesion. Patients' history, clinical and laboratory findings were collected and summarized. Lymphatic dissemination of CL in our patients manifested as subcutaneous nodules without epidermal involvement within the axis of lymphatic drainage toward the regional lymph node, at times accompanied by regional lymphadenopathy. In all patients, the lymphatic dissemination was not present at initial diagnosis of CL, appearing only after local (topical or intralesional) treatment was initiated. In three patients, the subcutaneous nodules resolved without systemic treatment. Lymphatic dissemination of Old World CL is not uncommon and may possibly be triggered by local treatment. It should be recognized by dermatologists, especially those working in endemic areas. Systemic treatment may be not necessary since spontaneous resolution may occur.

Autoimmune cytopenia is a frequent manifestation of primary immunodeficiencies. Two siblings presented with Evans syndrome, viral infections, and progressive leukopenia. DNA available from one patient showed a homozygous frameshift mutation in tripeptidyl peptidase II (TPP2) abolishing protein expression. TPP2 is a serine exopeptidase involved in extralysosomal peptide degradation. Its deficiency in mice activates cell death programs and premature senescence. Similar to cells from naïve, uninfected TPP2-deficient mice, patient cells showed increased major histocompatibility complex I expression and most CD8(+) T-cells had a senescent CCR7-CD127(-)CD28(-)CD57(+) phenotype with poor proliferative responses and enhanced staurosporine-induced apoptosis. T-cells showed increased expression of the effector molecules perforin and interferon-γ with high expression of the transcription factor T-bet. Age-associated B-cells with a CD21(-) CD11c(+) phenotype expressing T-bet were increased in humans and mice, combined with antinuclear antibodies. Moreover, markers of senescence were also present in human and murine TPP2-deficient fibroblasts. Telomere lengths were normal in patient fibroblasts and granulocytes, and low normal in lymphocytes, which were compatible with activation of stress-induced rather than replicative senescence programs. TPP2 deficiency is the first primary immunodeficiency linking premature immunosenescence to severe autoimmunity. Determination of senescent lymphocytes should be part of the diagnostic evaluation of children with refractory multilineage cytopenias.

All reported patients with hypomorphic X-linked severe combined immunodeficiency (X-SCID) due to c.664CT (p.R222C) mutations in the gene (IL2RG) encoding the common γ chain (γc) have presented with opportunistic infections within the first year of life, despite the presence of nearly normal NK and T cell numbers. Reporting five children of one extended family with hemizygous mutations in IL2RG, we explore potential diagnostic clues and extend our comprehension of the functional impact of this mutation.Whole exome sequencing (WES); detailed immune phenotyping; cytokine-induced STAT phosphorylation; B, T, and NK cell activation; and quantification of sjTRECs in five Arab children with c.664CT (p.R222C) IL2RG mutation.The mean age at clinical presentation with respiratory tract infection or diarrhea was 6.8 (range: 2-12) months. None of the children presented with opportunistic infections. Diagnostic clues were early onset in the first year of life, and a suggestive family history associated with reduced naïve CD4 T cells and absent switched memory B cells. Number and phenotype of NK cells and innate-like lymphocytes were normal. The diagnosis was made by WES and corroborated by absent STAT phosphorylation and reduced functional response after IL-2 and IL-21 stimulation. Four patients underwent successful hematopoietic stem cell transplantation.As early diagnosis and treatment are important, a high index of suspicion in the diagnosis of c.664CT (p.R222C) X-SCID is needed. This requires prompt genetic testing by next generation sequencing in order to avoid unnecessary delays in the definite diagnosis since immunological work up may not be discriminating. Assays directly testing cytokine signaling or cytokine-dependent functions are helpful in confirming the functional impact of the identified hypomorphic variants.

Background Recent data have shown an increasing occurrence of atopic dermatitis (AD) in children and adolescents, as well as in adults. Most of the epidemiologic research on AD is limited to pediatric and youth populations and is based on self-reported questionnaires. Methods A nationwide, population-based, cross-sectional retrospective study of adolescents with AD was performed to estimate its prevalence, trends, and association with demographic factors and comorbidities. The study included all Israeli teens going through medical evaluation as part of the assessment before being conscripted into the military from 1998 to 2013. Results A total of 1,187,757 adolescents were included in the study population, with an overall prevalence of AD of 0.64% in boys and 0.9% in girls. Over the study period, the prevalence of AD steadily increased, especially in the mild disease group. A greater risk of AD was found in subjects with high predicted socioeconomic status (male: odds ratio [OR] 1.14 [95% confidence interval {CI} 1.11, 1.16]; female: OR 1.08, [95% CI 1.05, 1.10]) and Israeli-born subjects (male: OR 1.34 [95% CI 1.21, 1.48]; female: OR 1.12 [95% CI 1.01, 1.23]). Allergic conditions such as asthma, conjunctivitis, and contact dermatitis were more prevalent in subjects with AD. There was a significantly higher prevalence of migraine in patients with AD (male: OR 1.35 [95% CI 1.18, 1.54]; female: OR 1.51 [95% CI 1.30, 1.74]). Conclusion This large cross-sectional study demonstrates the increasing prevalence of AD in adolescents and its relation to other allergic diseases and migraine. It is hoped that greater awareness of the distinctive epidemiologic characteristics of this population will lead to better recognition and management of the disease and its comorbidities.

Background The combination of palmoplantar keratoderma and woolly hair is uncommon and reported as part of Naxos and Carvajal syndromes, both caused by mutations in desmosomal proteins and associated with cardiomyopathy. We describe two large consanguineous families with autosomal-recessive palmoplantar keratoderma and woolly hair, without cardiomyopathy and with no mutations in any known culprit gene. The aim of this study was to find the mutated gene in these families. Methods and results Using whole-exome sequencing, we identified a homozygous missense c.2009C>T mutation in KANK2 in the patients (p.Ala670Val). KANK2 encodes the steroid receptor coactivator (SRC)-interacting protein (SIP), an ankyrin repeat containing protein, which sequesters SRCs in the cytoplasm and controls transcription activation of steroid receptors, among others, also of the vitamin D receptor (VDR). The mutation in KANK2 is predicted to abolish the sequestering abilities of SIP. Indeed, vitamin D-induced transactivation was increased in patient9s keratinocytes. Furthermore, SRC-2 and SRC-3, coactivators of VDR and important components of epidermal differentiation, are localised to the nucleus of epidermal basal cells in patients, in contrast to the cytoplasmic distribution in the heterozygous control. Conclusions These findings provide evidence that keratoderma and woolly hair can be caused by a non-desmosomal mechanism and further underline the importance of VDR for normal hair and skin phenotypes.

H syndrome is an autosomal recessive histiocytosis with multisystemic involvement caused by mutations in the SLC29A3 gene. The term H syndrome was coined to denote the major clinical findings which include hyperpigmentation, hypertrichosis, hearing loss, hepatosplenomegaly, hypogonadism, hyperglycemia/diabetes mellitus and hallux valgus/flexion contractures. Almost 100 individuals affected with this disorder have been reported, however, a thorough evaluation of the ophthalmologic features of H syndrome has not yet been performed.Ophthalmic examination of a 50-year-old male with H syndrome. Mutation analysis of SLC29A3 was also performed in this patient.Ophthalmic findings included; shallow orbits with exorbitism, bilateral pterygium, limbal thickening, corneal arcus and cortical cataract. We also review ophthalmologic findings in previously reported H syndrome patients.The presence of dilated lateral scleral vessels, corneal arcus and shallow orbits should raise the suspicion of H syndrome, especially when seen in young age.

Background H syndrome is an autosomal recessive genodermatosis with multisystem involvement caused by mutations in SLC29A3. Objective We sought to investigate the clinical and molecular findings in 79 patients with this disorder. Methods A total of 79 patients were included, of which 13 are newly reported cases. Because of the phenotypic similarity and molecular overlap with H syndrome, we included 18 patients with allelic disorders. For 31 patients described by others, data were gathered from the medical literature. Results The most common clinical features (>45% of patients) were hyperpigmentation, phalangeal flexion contractures, hearing loss, and short stature. Insulin-dependent diabetes mellitus and lymphadenopathy mimicking Rosai-Dorfman disease were each found in approximately 20%. Additional systemic features were described in less than 15% of cases. Marked interfamilial and intrafamilial clinical variability exists. Twenty mutations have been identified in SLC29A3, with no genotype-phenotype correlation. Limitations In the 31 patients described by others, data were collected from the medical literature. Conclusions H syndrome is a multisystemic disease with clinical variability. Consequently, all SLC29A3-related diseases should be considered a single entity. Recognition of the pleomorphic nature of H syndrome is important for diagnosis of additional patients.

Erythema multiforme (EM) is an immune-mediated reaction presenting as acrofacial target lesions. Most studies utilize the outdated classification, which includes EM, Stevens-Johnson syndrome and toxic epidermal necrolysis as related entities. We describe here epidemiological, aetiological, clinical, laboratory and treatment characteristics of paediatric EM. This is a retrospective single-centre study, performed between 2000 and 2013. Of 119 children given a diagnosis of EM, only 30 met clinical criteria and were included in this study. Most misdiagnosed cases were non-specific eruptions and urticaria multiforme. Mean age was 11.3 years. Fifty percent had mucosal involvement. An aetiology was observed in half of the patients. Seventy percent of patients were admitted to hospital, 46.7% were treated with systemic steroids. Sixteen percent had recurrent EM. The most common identified infectious agent associated with EM in this study was Mycoplasma pneumonia and the cases associated with this infection may represent the recent entity, mycoplasma-induced rash and mucositis. Association with herpes simplex virus was not observed. Despite being a benign, self-limiting condition, children were over-treated in terms of hospitalization and therapy.