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.

Arsenic is a natural element found in the earth\'s crust and is extensively present in various environmental components. Anthropogenic activities and a few natural events have generated contaminants that have led to massive environmental pollution, one form of which is arsenic contamination. Arsenic enters the human food chain via contaminated crops, water, seafood, and dairy products. In Pakistan, the increasing concentration of arsenic in the water is causing major health problems. Due to the serious health risks posed by arsenic, it is crucial to design and implement strategies for reducing and preventing the bioaccumulation of arsenic and its entry into the human food chain. There is a need for an institutional framework for arsenic mitigation, accountability, and systemic checks and balances. Targeted short- and long-term policies are required for effective and sustainable management.

Sarcoptic mange was detected in five free-ranging raccoon dogs (Nyctereutes procyonoides) in the federal state of Schleswig-Holstein, Germany, during a health assessment study of invasive species, including raccoon dogs, carried out between 2021 and 2022. Four raccoon dogs showed severe lesions, including extensive alopecia with thickening and hyperpigmentation of the skin (lichenification). The fifth animal was less affected, showing only thinning of the hair coat in multiple body locations. Skin scrapings were performed and confirmed the presence of Sarcoptes scabiei. Histopathology of the skin revealed diffuse epidermal hyperplasia and hyperkeratosis, mild eosinophilic dermatitis, and varying amounts of intralesional mites. Staphylococcus pseudintermedius and Corynebacterium auriscanis were detected in the skin samples of the affected animals, indicating a secondary bacterial infection. The source of sarcoptic mange remains unclear; interspecies transmission via direct or indirect contact seems likely. Raccoon dogs are therefore a potential vector for sarcoptic mange, and their behaviour could contribute to disease spread and persistence.

Ichthyoses are genetically determined cornification disorders of the epidermis characterized by the presence of different degrees of scaling, hyperkeratosis, and erythroderma often associated with palmoplantar keratoderma. Different classifications of these diseases have been proposed, often based upon the involved genes and/or the clinical presentation. The clinical features of these diseases present some overlap of phenotypes among distinct genetic entities, depending mainly on the penetrance of mutations. In this study, using a clinical, genetic, and molecular approach, we analyzed a family with two affected members who had clinical and histological features resembling erythrokeratodermia variabilis (EKV) or a type of erythrodermic hyperkeratosis with palmoplantar keratoderma. Despite of the clinical presentation, we demonstrated that the affected patients were genetically double heterozygous for two different mutations in the ABCA12 gene, known to be responsible for harlequin ichthyosis. To explain the mild phenotype of our patients, we performed a molecular characterization of the skin. In the upper layers of the epidermis, the results showed a patchy presence of the glucosyl-ceramides (GlcCer), which is the lipid transported by ABCA12, fundamental in contributing to skin impermeability. Indeed, the two mutations detected do not completely abolish ABCA12 activity, indicating that the mild phenotype is due to a partial loss of function of the enzyme, thus giving rise to an intermediate phenotype resembling EKVP, due to a partial depletion of GlcCer deposition.

Papillon-Lefevre syndrome (PLS) manifests as an autosomal recessive disorder caused by a mutation in the cathepsin C (CTSC) gene. This genetic alteration results in palmoplantar hyperkeratosis, rapid onset of periodontitis, and premature shedding of both primary and permanent teeth. The major etiological factor responsible for the development of this disorder appears to be variations in the CTSC gene, which is responsible for the production of the cathepsin C enzyme in the body. The multifactorial aetiology of the syndrome is influenced by immunologic, genetic, or microbial factors. This case report presents a clinical picture of a 21-year-old Indian male patient with oligodontia and mobile teeth accompanied by palmoplantar keratosis and a history of recurrent infection. The detailed family history of the patient revealed genetic relevance with PLS. This article will discuss in detail the diagnosis, evaluation and treatment modalities involved in the management of the case.

Onychomycosis can present with various manifestations such as subungual hyperkeratosis, onycholysis, and nail plate destruction. Here we present a case of a 61-year-old African male with a known case of type 2 diabetes mellitus on insulin. He worked as a mechanic and presented with nail changes that started four months prior to presentation and worsened over time, mainly affecting the fingernails of bilateral hands. On examination, there was yellowish to greenish discoloration with very extensive hyperkeratosis of skin around the fingers and nails that caused avulsion of nails. Swab and culture showed Candida albicans +3. Nail and skin biopsy showed bacterial colony with fungal hypha. The patient showed marked improvement after receiving oral fluconazole 300 mg weekly for three months.

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Granular parakeratosis (GP) is a unique keratotic disorder that often affects the intertriginous areas. GP usually presents as erythematous or brownish hyperkeratotic papules or plaques and can be further classified into five types. GP of the eccrine ostium is a rare subtype; its pathological defects are mainly localized to the stratum corneum of the eccrine ostia. Due to its rarity, there is usually a delay in diagnosing GP, and these patients are often misdiagnosed with other dermatological conditions. In this report, we present the case of a 64-year-old Thai female who presented with recurrent pruritic erythematous rashes on her neck since approximately 40 years. She was previously diagnosed with eczema or folliculitis. Histopathological examination confirmed a final diagnosis of GP of the eccrine ostium. She was advised to avoid excessive heat and keep her intertriginous areas dry. Her condition improved significantly during the follow-up visit.

Familial dyskeratotic comedones (FDC) is an autosomal dominant inherited skin disorder characterized by generalized multiple discrete comedone-like hyperkeratotic papules. The disease demonstrates a distinct histopathologic feature of dyskeratosis of the crater-like invaginated epidermis or follicle-like structures with or without acantholysis. Despite its asymptomatic and benign course, the condition is refractory to treatment. Herein, we report a case of a 54-year-old female presenting with progressively developed generalized multiple hyperkeratotic papules with central keratin plugs on the trunk and extremities for 20 years. A definite diagnosis was made by clinical manifestations and histopathological examination. The lesions were slightly improved after 3 months of topical retinoids and urea cream treatments. Besides, we first describe dermoscopic findings of FDC and reviewed 21 previously reported FDC cases from 11 families in the literature.

Chronic progressive lymphedema (CPL) in draft horses is characterized by increased dermal thickness and fibrosis, with the development of skinfolds and nodules, hyperkeratosis, and ulcerations on the distal limbs of affected horses. Secondary bacterial, fungal, or parasitic infections frequently complicate and aggravate the lesions, as well as the progression of this disease. CPL has a particularly high prevalence of up to 85.86% in the Belgian draft horse breed. Due to the disease\'s progressive and incurable nature, affected horses are often euthanized prematurely. The treatment options are solely symptomatic, aimed at improving the horse\'s quality of life. Despite the severity of this condition, many uncertainties about its etiology and pathogenesis still remain to date. The established scientific research on CPL is rather limited, although there is an urgent need for strategies to tackle this disease. This review summarizes the available knowledge, serving as a guideline for practitioners, and provides perspectives for future research programs.