Dermoscopic Examination of Tinea Nigra on the Plantar Foot Unveils a Parallel Ridge Pattern Mimicking Acral-Lentiginous Melanoma.

A man in his thirties patient visited his previous physician with the chief complaint of a pigmented macule on the sole of his left foot that had steadily grown over the past two years. A dermoscopic examination of the lesion showed a parallel ridge pattern (PRP); therefore, acral-lentiginous melanoma (ALM) was suspected, and the patient was referred to our hospital for a more detailed examination. On closer inspection, PRP had a well-defined and irregular border with no variation in color, which is atypical for ALM which is characterized by asymmetrical structure and variation in colors.

Type 2 cytokine-JAK1 signaling is involved in the development of dry skin-induced mechanical alloknesis.

Background: Mechanical alloknesis (m-alloknesis) is itch hypersensitivity induced by normally innocuous stimuli. It is sometimes observed in dry skin based itch-related diseases such as atopic dermatitis (AD), and often triggers the vicious itch-scratch cycle. The acetone-ether and water (AEW) mouse model mimics dry skin-induced m-alloknesis, yet its underlying mechanism remains unclear.

Stress-experienced monocytes/macrophages lose anti-inflammatory function via β-adrenergic receptor in skin allergic inflammation.

Background: Psychological stress can exacerbate the development of allergies; however, the underlying mechanisms remain poorly understood. IgE-mediated cutaneous allergic inflammation (IgE-CAI) is a basophil-dependent skin allergy with eosinophil infiltration at inflammatory sites. Its resolution involves anti-inflammatory programmed death ligand 2 (PD-L2)-positive macrophages.

Ligand-independent function of β2-adrenergic receptor affects IgE-mediated Ca influx in mast cells.

Background: Mast cells are key effector cells that elicit immunoglobulin E (IgE)-mediated allergic inflammations. Allergen cross-linking of IgE bound to the high-affinity IgE receptor, FcεRI, on mast cells triggers signaling cascades that activate signal proteins and evoke extracellular Ca influx, which are crucial for cytokine production. The β2-adrenergic receptor (Adrb2) on mast cells negatively regulates FcεRI signaling, as demonstrated by the inhibition of IgE/antigen (Ag)-induced activation by Adrb2 agonists.

Model of Chronic Itch in Aged Mice: Beneficial Effects of Drugs Affecting Descending Modulatory Systems.

Pruritus in the elderly, particularly those cases without skin dryness or other identifiable causes, makes treatment challenging due to the lack of evidence regarding the therapeutic effects of antipruritics. This study proposes an age-related alloknesis mouse model for an evaluation system for such cases, and aimed to investigate the effectiveness and mechanisms of action of several drugs commonly used as antipruritics in Japan, utilizing this model. Mice 69-80 weeks old were used as aged mice, and the level of mechanical alloknesis was counted as the number of scratching behaviours in response to innocuous stimuli.

Effects of Psychological Stress on Spontaneous Itch and Mechanical Alloknesis of Atopic Dermatitis.

Atopic dermatitis (AD), a chronic inflammatory skin disease, manifests as an intractable itch. Psychological stress has been suggested to play a role in the onset and worsening of AD symptoms. However, the pathophysiological relationships between psychological stressors and cutaneous manifestations remain unclear.

Phylactic role of anti-lipoarabinomannan IgM directed against mannan core during mycobacterial infection in macrophages.

Mycobacteria enter host phagocytes, such as macrophages by binding to several receptors on phagocytes. Several mycobacterial species, including Mycobacterium tuberculosis have evolved systems to evade host bactericidal pathways. Lipoarabinomannan (LAM) is an essential mycobacterial molecule for both binding to phagocytes and escaping from bactericidal pathways.

Increased production of natural moisturizing factors and bleomycin hydrolase activity in elderly human skin.

Background: Bleomycin hydrolase (BH), which is expressed in the stratum granulosum and lower stratum corneum (SC), is involved in final filaggrin degradation. Furthermore, BH plays an essential role in producing free amino acids, which constitute the majority of natural moisturizing factors (NMF). However, the effects of BH expression and protease activity on human skin aging remain unclear.

A severe case of primary erythromelalgia presenting as small fiber neuropathy with a novel SCN9A mutation.

Primary erythromelalgia (PEM) is a rare condition characterized by severe burning pain, erythema, and increased temperature in the extremeties. Mutations in the Nav1.7 sodium channel encoded by the SCN9A are responsible for PEM.

Effects of Dupilumab on Itch-Related Events in Atopic Dermatitis: Implications for Assessing Treatment Efficacy in Clinical Practice.

Dupilumab attenuates itch and skin inflammation in patients with atopic dermatitis (AD). However, itch-related events that are improved by dupilumab remain unclear. Therefore, the present study investigated changes in clinical scores, serum biomarkers, and the number of intraepidermal nerve fibers (IENFs) using skin biopsies and blood samples from 12 patients with moderate to severe AD before and after treatment with dupilumab.

An Altered Skin and Gut Microbiota Are Involved in the Modulation of Itch in Atopic Dermatitis.

Skin and gut microbiota play an important role in the pathogenesis of atopic dermatitis (AD). An alteration of the microbiota diversity modulates the development and course of AD, e.g.

Experimental and Clinical Evidence Suggests That Treatment with Betacellulin Can Alleviate Th2-Type Cytokine-Mediated Impairment of Skin Barrier Function.

Betacellulin (BTC) is a peptide ligand that belongs to the epidermal growth factor family, the members of which have been implicated in skin morphogenesis, homeostasis, repair, and angiogenesis; however, the role of BTC in the regulation of the skin barrier remains unknown. To examine the role of BTC in skin barrier function, we analyzed atopic dermatitis (AD) transcriptomic data from Gene Expression Omnibus (GEO) datasets, performed BTC immunohistochemistry using human skin tissues, and evaluated the effects of BTC on primary human keratinocytes by real-time PCR, Western blotting, and assay of the transepidermal electrical resistance (TER), a functional parameter to monitor the tight junction barrier. We found that the gene expression of BTC was downregulated in skin lesions from patients with AD, and this downregulated expression recovered following biological treatments.

Treatment Options for Troublesome Itch.

Itch (or pruritus) is an unpleasant sensation, inducing the desire to scratch. It is also a major and distressing symptom of many skin and systemic diseases. The involvement of histamine, which is a major itch mediator, has been extensively examined.

Skin Treatment with Detergent Induces Dermatitis with H1-Antihistamine-Refractory Itch and Upregulates IL-4 and Th17/Th22 Cytokine Gene Expression in C57BL/6 Mice.

Introduction: Repeated skin contact to detergents causes chronic irritant contact dermatitis (ICD) associated with itch sensation and eczema. However, the mechanisms of detergent-induced ICD are poorly understood. Here, we established a new murine model of detergent-induced ICD with H1-antihistamine-refractory itch.

Human β-defensin-3 attenuates atopic dermatitis-like inflammation through autophagy activation and the aryl hydrocarbon receptor signaling pathway.

Human β-defensin-3 (hBD-3) exhibits antimicrobial and immunomodulatory activities; however, its contribution to autophagy regulation remains unclear, and the role of autophagy in the regulation of the epidermal barrier in atopic dermatitis (AD) is poorly understood. Here, keratinocyte autophagy was restrained in the skin lesions of patients with AD and murine models of AD. Interestingly, hBD-3 alleviated the IL-4- and IL-13-mediated impairment of the tight junction (TJ) barrier through keratinocyte autophagy activation, which involved aryl hydrocarbon receptor (AhR) signaling.

The Bactericidal Effect of MA-T for Factitiously Contaminated and Used Masks.

Matching transformation system (MA-T), an on-demand aqueous chlorine dioxide solution, is an excellent safety disinfectant, because chlorine dioxide is not detected during storage or before use. The production of chlorine dioxide in MA-T is induced by a catalytic reaction in the presence of target microorganisms. In this study, we investigated MA-T disinfection of masks as a reuse method to eliminate mask shortages.

Peripheral itch sensitization in atopic dermatitis.

Atopic dermatitis is a skin disorder caused by skin dryness and barrier dysfunction, resulting in skin inflammation and chronic itch (or pruritus). The pathogenesis of atopic dermatitis is thought to be initiated by a lowering of the itch threshold due to dry skin. This lowering of the itch threshold is at least partially due to the increase in intraepidermal nerve fibers and sensitization of sensory nerves by interleukin (IL)-33 produced and secreted by keratinocytes.

Kerion Celsi Caused by Nannizzia gypsea in a Two-Year-Old Child Who Had Been Hospitalized Since Birth.

Nannizzia gypsea, previously known as Microsporum gypseum, is a geophilic dermatophyte that infects humans from the soil. We isolated N. gypsea from a two-year-old girl with kerion celsi.