CASTing the net wider: A case report of PLACK syndrome associated with dilated cardiomyopathy.

PLACK syndrome (OMIM 616295) is a rare genodermatosis associated with peeling skin, leukonychia, acral punctate keratosis, cheilitis, and knuckle pads and is caused by loss-of-function mutations in the CAST gene, which encodes calpastatin, a calcium-dependent protease. This case report highlights a case of PLACK syndrome presenting with the unique findings of striate hyperkeratosis on the palms as well as life-threatening cardiomyopathy. We review why CAST mutations might impact cardiac function and raise awareness of the potential association between PLACK syndrome and cardiac manifestations.

Unilateral focal palmoplantar keratoderma associated with a postzygotic variant in PIK3CA and activation of the PI3K/AKT/mTOR pathway.

Palmoplantar keratoderma (PPK) is a group of -disorders with genetic and phenotypic heterogeneity featuring skin thickening of the palms and soles. More than 60 genes involved in various biological processes are implicated in PPK. PIK3CA is an oncogene encoding p110α, and its somatic variants contribute to a spectrum of congenital overgrowth disorders, including epidermal nevi (EN). To identify the genetic basis and elucidate the pathogenesis of a patient with unilateral focal PPK. Whole-exome sequencing and Sanger sequencing combined with laser capture microdissection (LCM) were performed on genomic DNA extracted from the patient's peripheral blood and skin lesion. Skin biopsies were taken from the lesion of the patient and normal controls for immunofluorescence. Molecular docking was performed using Alphafold2-multimer. A three-year-old girl presented with unilateral focal PPK with an identified missense -variant (c.3140A>G, p.His1047Arg) in PIK3CA from affected tissue. This variant only existed in the lesional epidermis. Elevated PI3K/AKT/mTOR signalling in the affected epidermis and an increased number of Ki67-positive keratinocytes were demonstrated. Molecular docking indicated instability of the p110α-p85α dimer caused by the PIK3CA His1047Arg variant. We describe the first PPK case associated with a variant in PIK3CA, which expands the spectrum of PIK3CA-related disorders. Our study further underscores the importance of the PI3K/AKT/mTOR pathway in the homeostasis of skin keratinization.

A novel approach with tofacitinib for the management of keratoderma blennorrhagicum in reactive arthritis: a case report.

Reactive arthritis(ReA), a form of arthritis occurring post-infection, manifests with antecedent infection symptoms, arthritis, and extra-articular manifestations, categorizing it as spondyloarthritis. "Keratoderma blennorrhagicum" (characterized by pustular hyperkeratosis on palms and soles, resembling pustular psoriasis) represents the most typical skin manifestation of ReA, occurring in acute or chronic phases. Severe lesions necessitate systemic disease modifying anti-rheumatic drugs (DMARDs) or biologic therapies. This article reports a case of ReA with sacroiliitis and widespread pustular eruptions following a urinary tract infection. Treatment with sulfasalazine and thalidomide significantly improved sacroiliitis, but the skin rash remained persistent and recurring. Subsequent use of adalimumab and secukinumab resulted in worsening skin rash, prompting a switch to tofacitinib, leading to a remarkable improvement in pustular eruptions after 20 days of treatment. This case demonstrates successful application of tofacitinib in treating severe keratoderma blennorrhagicum refractory to conventional DMARDs and biologics, offering insights into JAK inhibition for challenging rheumatic diseases with skin involvement.

A novel FAM83G variant from palmoplantar keratoderma patient disrupts WNT signalling via loss of FAM83G-CK1α interaction.

Palmoplantar keratoderma (PPK) is a multi-faceted skin disorder characterized by the thickening of the epidermis and abrasions on the palms and soles of the feet. Among the genetic causes, biallelic pathogenic variants in the FAM83G gene have been associated with PPK in dogs and humans. Here, a novel homozygous variant (c.794G>C, p.Arg265Pro) in the FAM83G gene, identified by whole exome sequencing in a 60-year-old female patient with PPK, is reported. The patient exhibited alterations in the skin of both hands and feet, dystrophic nails, thin, curly and sparse hair, long upper eyelid eyelashes, and poor dental enamel. FAM83G activates WNT signalling through association with ser/thr protein kinase CK1α. When expressed in FAM83G-/- DLD1 colorectal cancer cells, the FAM83GR265P variant displayed poor stability, a loss of interaction with CK1α and attenuated WNT signalling response. These defects persisted in skin fibroblast cells derived from the patient. Our findings imply that the loss of FAM83G-CK1α interaction and subsequent attenuation of WNT signalling underlie the pathogenesis of PPK caused by the FAM83GR265P variant.

[Palmoplantar dermatoses: Diagnostic approach in primary care]. / Dermatosis palmoplantares: aproximación diagnóstica en atención primaria.

This article addresses the diagnostic challenges of palmoplantar dermatoses (PPD) within the scope of Primary Health Care (PHC). These common skin conditions, encountered in daily practice, exhibit a diverse range of symptoms and morphologies, complicating their diagnosis. They are etiologically classified into infectious inflammatory, non-infectious inflammatory, and hereditary keratodermas. While various dermatoses may affect the palms and soles, few are specific to this area. Notable examples include palmoplantar pustulosis, dyshidrosis, erythema pernio, and Bazex syndrome. Given the high prevalence of dermatological consultations in PHC, this article underscores the significance of PHC professionals' knowledge regarding these conditions. It proposes a diagnostic algorithm to facilitate their management and timely referral.

Transgradient Variant of Mal De Meleda Presenting As Palmoplantar Keratoderma: A Case Report.

Mal De Meleda is a rare genetic disorder characterized by palmoplantar keratoderma, often presenting challenges in diagnosis and management. This case report discusses an 18-year-old male presenting with thickened, yellowish skin on both palms and soles, accompanied by itching and cracking. A diagnosis of the transgradiens variant of Mal De Meleda was established through clinical and histopathological examination. Treatment with oral acitretin and topical moisturizers resulted in significant improvement. This report highlights the importance of recognizing rare variants of palmoplantar keratoderma and the need for a multidisciplinary approach to diagnosis and management.

Pain Hypersensitivity in SLURP1 and SLURP2 Knock-out Mouse Models of Hereditary Palmoplantar Keratoderma.

SLURP1 and SLURP2 are both small secreted members of the Ly6/u-PAR family of proteins and are highly expressed in keratinocytes. Loss-of-function mutations in SLURP1 lead to a rare autosomal recessive palmoplantar keratoderma (PPK), Mal de Meleda (MdM), which is characterized by diffuse, yellowish palmoplantar hyperkeratosis. Some individuals with MdM experience pain in conjunction with the hyperkeratosis that has been attributed to fissures or microbial superinfection within the affected skin. By comparison, other hereditary PPKs such as pachyonychia congenita and Olmsted syndrome show prevalent pain in PPK lesions. Two mouse models of MdM, Slurp1 knock-out and Slurp2X knock-out, exhibit robust PPK in all four paws. However, whether the sensory experience of these animals includes augmented pain sensitivity remains unexplored. In this study, we demonstrate that both models exhibit hypersensitivity to mechanical and thermal stimuli as well as spontaneous pain behaviors in males and females. Anatomical analysis revealed slightly reduced glabrous skin epidermal innervation and substantial alterations in palmoplantar skin immune composition in Slurp2X knock-out mice. Primary sensory neurons innervating hindpaw glabrous skin from Slurp2X knock-out mice exhibit increased incidence of spontaneous activity and mechanical hypersensitivity both in vitro and in vivo. Thus, Slurp knock-out mice exhibit polymodal PPK-associated pain that is associated with both immune alterations and neuronal hyperexcitability and might therefore be useful for the identification of therapeutic targets to treat PPK-associated pain.

SERPINB7 Deficiency Increases Legumain Activity and Impairs the Epidermal Barrier in Nagashima-Type Palmoplantar Keratoderma.

Nagashima-type palmoplantar keratoderma is an autosomal recessive genodermatosis caused by loss-of-function variants in SERPINB7 and is the most prevalent form of inherited palmoplantar keratodermas among Asians. However, there is currently no effective therapy for Nagashima-type palmoplantar keratoderma because its pathogenesis remains unclear. In this study, Serpinb7-/- mice were generated and spontaneously developed a disrupted skin barrier, which was further exacerbated by acetone-ether-water treatment. The skin of these Serpinb7-/- mice showed weakened cytoskeletal proteins. In addition, SERPINB7 deficiency consistently led to decreased epidermal differentiation in a 3-dimensional human epidermal model. We also demonstrated that SERPINB7 was an inhibitory serpin that mainly inhibited the protease legumain. SERPINB7 bound directly with legumain and inhibited legumain activity both in vitro and in vivo. Furthermore, we found that SERPINB7 inhibited legumain in a protease-substrate manner and identified the cleavage sites of SERPINB7 as Asn71 and Asn343. Overall, we found that SERPINB7 showed the nature of a cysteine protease inhibitor and identified legumain as a key target protease of SERPINB7. Loss of SERPINB7 function led to overactivation of legumain, which might disrupt cytoskeletal proteins, contributing to the impaired skin barrier in Nagashima-type palmoplantar keratoderma. These findings may lead to the development of therapeutic strategies for Nagashima-type palmoplantar keratoderma.

Case report of crusted scabies, brief review of its pathophysiology and latest data.

Background: Crusted scabies is a rare form of parasitic infection provoked by a massive infestation of the ectoparasite Sarcoptes scabiei varietas hominis on human skin. It is an extremely contagious type of disease and can even lead to a social stigma. In European countries like Greece, many cases remain undiagnosed for long periods, causing extreme distress in the patient's everyday life and social environment. Case Description: Herein, we present a case of an 86-year-old woman with crusted scabies in Greece, who remained undiagnosed for 5 months. Massive hyperkeratotic plaques on the extremities, and face, palmoplantar keratoderma, and numerous small erythematous papules on the torso with extreme itch were the main clinical manifestations of the patient. Dermoscopy revealed the parasite. All necessary decontamination measures were taken by personnel. Treatment was administered and a complete cure of the disease was observed. Conclusions: In this case, the use of dermoscopy has attributed to precise crusted scabies diagnosis and acute pharmacological management of the patient. Early diagnosis of such diseases not only saves patients from lethal secondary infections, but also reduces the risk of a massive scabies outbreak. We also conducted a mini-review, analyzing all recent data concerning crusted scabies macroscopic, dermatoscopic, and histological images. All new information concerning the pathophysiological mechanism of crusted scabies manifestation, updated treatment options, and potential resistance to widely-used treatments are provided.

Hereditary epidermolytic palmoplantar keratosis due to a novel desmoglein-1 mutation: A case report.

Key Clinical Message: Keratosis palmoplantaris striata type I (SPPK-I) is a rare autosomal-dominant type of hereditary epidermolytic palmoplantar keratoderma, which can be caused by mutations in desmoglein-1 (DSG-1). Patients suffer from hyperkeratotic plaques and painful palmoplantar fissures. Unfortunately, treatment options including salicylic vaseline, topical corticosteroids, phototherapy, and retinoids are inefficient. Abstract: Hereditary palmoplantar keratodermas (PPKs) represent a heterogeneous group of rare skin disorders with epidermal palmoplantar hyperkeratosis. Mutations in the desmoglein 1 gene (DSG1), a transmembrane glycoprotein, have been reported primarily in striate PPKs. We report a patient with keratosis palmoplantaris striata type I (SPPK-I) with a specific pathogenic variant [c.349C>T, p.(Arg117*)] in DSG1. Despite increased understanding, effective treatment options for PPK, including SPPK-I, remain limited.

A Case of Palmoplantar Keratoderma in the Constellation of Connective Tissue Diseases.

Overlap syndrome is a clinical challenge and brings together a wide range of treatment options for the treating physician. Addressing each and every complaint of the patient is crucial. A 50-year-old female patient presented with skin thickening, blackening, and hyperkeratosis; dysphagia; joint pain; features of myopathy; Raynaud's phenomenon; and dry mouth. Inflammatory markers were raised along with a positive antinuclear antibody (ANA) with Golgi apparatus pattern, anti-Sjögren's-syndrome-related antigen A (anti-SSA)/Ro60 3+, anti-SSA/Ro52 3+, and anti-PM/Scl 2+ antibodies that suggested overlap syndrome. Although the patient had no respiratory complaints, a unique interstitial lung disease (ILD) pattern was noted during the evaluation. Skin manifestations were puzzling, but the histopathology analyses of skin biopsies taken from two different sites revealed distinguishing features of cutaneous lupus and dermatomyositis. Treatment with hydroxychloroquine, pilocarpine, nifedipine, methotrexate, and topical tacrolimus produced a dramatic improvement in the clinical features. This case highlights subtle and florid features of different autoimmune diseases. The hyperkeratotic skin changes were the most striking feature, but the whole evaluation process unveiled many rare presentations of known autoimmune conditions that can open doors to new areas of our understanding toward connective tissue diseases (CTDs). Our case report demonstrates significant heterogeneity in the ANA patterns, ILD patterns, clinical manifestations, and treatment approaches.