Lichen sclerosus (LS) is a chronic, inflammatory, mucocutaneous disorder of genital and extragenital skin. LS is a debilitating disease, causing itch, pain, dysuria and restriction of micturition, ...dyspareunia, and significant sexual dysfunction in women and men. Many findings obtained in recent years point more and more towards an autoimmune-induced disease in genetically predisposed patients and further away from an important impact of hormonal factors. Preceding infections may play a provocative part. The role for
Borrelia
is still controversial. Trauma and an occlusive moist environment may act as precipitating factors. Potent and ultrapotent topical corticosteroids still head the therapeutic armamentarium. Topical calcineurin inhibitors are discussed as alternatives in the treatment of LS in patients who have failed therapy with ultrapotent corticosteroids, or who have a contraindication for the use of corticosteroids. Topical and systemic retinoids may be useful in selected cases. Phototherapy for extragenital LS and photodynamic therapy for genital LS may be therapeutic options in rare cases refractory to the already mentioned treatment. Surgery is restricted to scarring processes leading to functional impairment. In men, circumcision is effective in the majority of cases, but recurrences are well described. Anogenital LS is associated with an increased risk for squamous cell carcinoma of the vulva or penis. This review updates the epidemiology, clinical presentation, histopathology, pathogenesis, and management of LS of the female and male genitals and extragenital LS in adults and children.
Humans lacking sclerostin display progressive bone overgrowth due to increased bone formation. Although it is well established that sclerostin is an osteocyte-secreted bone formation inhibitor, the ...underlying molecular mechanisms are not fully elucidated. We identified in tandem affinity purification proteomics screens LRP4 (low density lipoprotein-related protein 4) as a sclerostin interaction partner. Biochemical assays with recombinant proteins confirmed that sclerostin LRP4 interaction is direct. Interestingly, in vitro overexpression and RNAi-mediated knockdown experiments revealed that LRP4 specifically facilitates the previously described inhibitory action of sclerostin on Wnt1/β-catenin signaling. We found the extracellular β-propeller structured domain of LRP4 to be required for this sclerostin facilitator activity. Immunohistochemistry demonstrated that LRP4 protein is present in human and rodent osteoblasts and osteocytes, both presumed target cells of sclerostin action. Silencing of LRP4 by lentivirus-mediated shRNA delivery blocked sclerostin inhibitory action on in vitro bone mineralization. Notably, we identified two mutations in LRP4 (R1170W and W1186S) in patients suffering from bone overgrowth. We found that these mutations impair LRP4 interaction with sclerostin and its concomitant sclerostin facilitator effect. Together these data indicate that the interaction of sclerostin with LRP4 is required to mediate the inhibitory function of sclerostin on bone formation, thus identifying a novel role for LRP4 in bone.
Juvenile xanthogranuloma (JXG) is the most common type of non-Langerhans cell histiocytosis. JXG is a rare benign tumor, which may be present at birth or develop later. The classical form of JXG is ...characterized by a red-yellowish benign papule or nodule with predilection sites on the head, neck, and trunk, although lesions can appear on extremities or extracutaneous sites. In most cases there is only one lesion, whereas numerous papules or nodules may occur. Special forms of JXG such as mixed, giant, subcutaneous, eruptive, clustered, and plaque-like have been reported and associations between JXG and systemic diseases have been made. Diagnosis mainly relies on the clinical appearance, and histology usually can confirm the disease. Here we present a very rare case of symmetrical giant facial plaque-type juvenile xanthogranuloma (SGFP-JXG) and compare it with classical JXG, variations of JXG, and discuss the differential diagnosis. A 4-year-old Caucasian female presented with plaque-like lesions composed of yellowish confluent papules on both the cheeks. The histological evaluation revealed a histiocytic lesion with a formation of Touton giant cells and immunohistochemistry results confirmed the diagnosis of the SGFP-JXG. In comparison to classical JXG, the onset of SGFP-JXG sometimes occurs later and the spontaneous resolution period may be prolonged. No associated diseases and no systemic involvements were observed. Histopathology is required to differentiate this form of JXG from other histiocytosis. To the best of our knowledge, only four cases of SGFP-JXG have been reported in the literature so far.
Disorders of Pigmentation Fistarol, Susanna K.; Itin, Peter H.
Journal der Deutschen Dermatologischen Gesellschaft,
March 2010, Letnik:
8, Številka:
3
Journal Article
Recenzirano
Summary
Skin color is highly individual and the variations are controlled by numerous genes. The different skin colors result from the size and number of melanosomes and do not mirror the amount of ...melanocytes. Disorders of pigmentation can result from migration abnormalities of melanocytes from the neural crest to the skin during embryogenesis. In addition, impairment of melanosome transfer to the surrounding keratinocytes, an alteration in melanin synthesis and a defective degradation or removal of melanin may lead to abnormal skin pigmentation. Immunologic or toxic mediated destructions of melanocytes can end in pigmentation disorders. Disorders of pigmentation are classified in hypo‐ or hyperpigmentation which can occur as a genetic or acquired disease. They can manifest locally or diffuse. Congenital hypopigmentation can be restricted to the skin as in piebaldism or they represent a systemic disease as in Menkes disease or phenylketonuria. Localized hypo‐ or hyperpigmentation in children may serve as markers for systemic diseases. Ash‐leaf hypopigmentation are characteristic for tuberous sclerosis and more than 5 café‐au‐lait spots suggest neurofibromatosis 1 (von Recklinghausen disease). The most common autoimmune‐induced depigmentation is vitiligo. Generalized hyperpigmentation only rarely reflects a primary genetic disorder but is most often from acquired diseases as in Addison disease, secondary hemochromatosis or primary biliary cirrhosis. Treatment of pigmentation disorders are based on a diagnosis which sometimes allow a specific intervention. Cosmetically acceptable results are difficult to obtain.
Epidermodysplasia verruciformis (EV) is an autosomal recessive skin disorder with a phenotype conditional on human beta-papillomavirus (beta-HPV) infection. Such infections are common and ...asymptomatic in the general population, but in individuals with EV, they lead to the development of plane wart-like and red or brownish papules or pityriasis versicolor-like skin lesions, from childhood onwards. Most patients develop non-melanoma skin cancer (NMSC), mostly on areas of UV-exposed skin, from the twenties or thirties onwards. At least half of the cases of typical EV are caused by biallelic loss-of-function mutations of
or
. The cellular and molecular basis of disease in TMC/EVER-deficient patients is unknown, but a defect of keratinocyte-intrinsic immunity to beta-HPV is suspected. Indeed, these patients are not susceptible to other infectious diseases and have apparently normal leukocyte development. In contrast, patients with an atypical form of EV due to inborn errors of T-cell immunity invariably develop clinical symptoms of EV in the context of other infectious diseases. The features of the typical and atypical forms of EV thus suggest that the control of beta-HPV infections requires both EVER1/EVER2-dependent keratinocyte-intrinsic immunity and T cell-dependent adaptive immunity.
We report here the case of a 12-year-old boy with erythema ab igne on his left thigh caused by the use of a laptop computer. This is the youngest of the 10 reported patients with this laptop-induced ...dermatosis since its first description in 2004. Erythema ab igne is a reticular, pigmented, sometimes telangiectatic dermatosis that is caused by prolonged exposure to a heat or infrared source. In laptop-induced erythema ab igne, the localization on the thighs and asymmetry are characteristic. The heat originates from the optical drive, the battery, or the ventilation fan of the computer.
Epidermodysplasia verruciformis (EV) is a genodermatosis characterized by the inability of keratinocytes to control cutaneous β-HPV infection and a high risk for non-melanoma skin cancer (NMSC). ...Bi-allelic loss of function variants in TMC6, TMC8, and CIB1 predispose to EV. The correlation between these proteins and β-HPV infection is unclear. Its elucidation will advance the understanding of HPV control in human keratinocytes and development of NMSC. We generated a cell culture model by CRISPR/Cas9-mediated deletion of CIB1 to study the function of CIB1 in keratinocytes. Nine CIB1 knockout and nine mock control clones were generated originating from a human keratinocyte line. We observed small changes in gene expression as a result of CIB1 knockout, which is consistent with the clearly defined phenotype of EV patients. This suggests that the function of human CIB1 in keratinocytes is limited and involves the restriction of β-HPV. The presented model is useful to investigate CIB1 interaction with β-HPV in future studies.
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