Platelet-rich plasma (PRP) therapy has gained attention in the scientific field due to its potential regenerative effects and great benefit–risk ratio. This review extensively explores the most studied mechanisms of this therapy according to the etiopathogenesis of skin diseases: cellular proliferation, matrix formation, regulation of inflammation, angiogenesis, collagen synthesis, and the remodeling of new tissue. Moreover, it draws on newly reported and lesser-known effects of PRP: its anti-apoptotic effects, immunological suppression, decrease in melanin synthesis, anti-microbial effects, overexpression of miR-155, antioxidant effects, and their involved pathways. This work aims to provide a complete update for understanding PRP’s benefits and clinical relevance in wound healing, alopecia, pigmentary disorders, scars, rejuvenation, lichen sclerosus, and other inflammatory dermatoses, based on the current evidence. Furthermore, recent reports with novel indications for PRP therapy are highlighted, and new potential pathways correlated with the pathogenesis of skin diseases are explored.

The incidence of syphilis, gonorrhea, chlamydia, and herpes simplex has increased over the last decade, despite the numerous prevention strategies. Worldwide scientists report a surge in drug-resistant infections, particularly in immunocompromised patients. Antigenic variations in syphilis enable long-term infection, but benzathine penicillin G maintains its efficiency, whereas macrolides should be recommended with caution. Mupirocin and zoliflodacin were recently introduced as therapies against ceftriaxone-resistant gonococcus, which poses a larger global threat. The gastrointestinal and prostatic potential reservoirs of Chlamydia trachomatis may represent the key towards complete eradication. Similar to syphilis, macrolides resistance has to be considered in genital chlamydiosis. Acyclovir-resistant HSV may respond to the novel helicase-primase inhibitors and topical imiquimod, particularly in HIV-positive patients. Novel drugs can overcome these challenges while nanocarriers enhance their potency, particularly in mucosal areas. This review summarizes the most recent and valuable discoveries regarding the immunopathogenic mechanisms of these sexually transmitted infections and discusses the challenges and opportunities of the novel molecules and nanomaterials.

Recently recognised as a desmosomal disorder, autoimmune pemphigus remains severe in some of its forms, such as pemphigus vulgaris. This review is divided into four parts. “Cellular and molecular mechanisms in autoimmune pemphigus” discusses in detail antigenic targets, antibodies, immunological and genetic mechanisms of apoptosis and the involvement of cells and organelles (keratinocytes, lymphocytes, eosinophils and neutrophils) in different forms of pemphigus. These advances have led to today’s first-line biologic therapy for pemphigus. The section “Specific features in the diagnosis of immune pemphigus” deals with the clinical diagnostic clues (enanthema, intertrigo, pruritus, distribution of lesions). The third section, “Characteristics and challenges in different types of pemphigus”, focuses on the importance of using standardised diagnostic criteria in paraneoplastic pemphigus and pemphigus herpetiformis, the specific and difficult situations of differentiation between bullous lupus and autoimmune Senear-Usher pemphigus, between IgA forms of pemphigus or differentiation with other autoimmune diseases or neutrophilic dermatoses. The possibility of subtype cross-reactivity in pemphigus is also discussed, as is the diagnosis and course of the disease in pregnant women. The final section is an update of the “gold standard for the diagnosis and evaluation of autoimmune pemphigus”, the role and place of direct immunofluorescence and additional serological tests. This revision is the first to combine the difficulties in clinical diagnosis with new molecular insights. It provides a comprehensive overview of recent advances in the understanding of autoimmune pemphigus, bridging the clinical challenges and complexities of diagnosing different forms of pemphigus, and is a valuable resource for clinicians caring for patients with pemphigus.

Cutaneous squamous cell carcinoma (cSCC) is the second-most-prevalent malignancy in humans. A delayed diagnosis of cSCC leads to heightened invasiveness and positive surgical margins. Bowen’s disease (BD) represents an early form of cSCC and presents as a small erythematous, photo-distributed, psoriasiform plaque. Although certain dermoscopy features in BD are quite characteristic, histopathology remains the gold standard for diagnosis and provides a severity-scoring system that assists in guiding appropriate treatment strategies. The classification of precancerous lesions of the vulva and penis has undergone multifarious transformations due to variations in clinical and histopathological characteristics. Presently, erythroplasia of Queyrat is categorized as a clinical variant of penile intraepithelial neoplasia (PeIN). The diagnoses of vulvar intraepithelial neoplasia (VIN) and PeIN present significant challenges and typically necessitate one or more biopsies, potentially guided by dermoscopy. Aceto-white testing demonstrates a notably high negative predictive value for genital precancerous lesions. Histopathological examination represents the gold-standard diagnosis in VIN and PeIN, while p16 and p53 immunostainings alongside HPV testing provide crucial diagnostic clues. The histopathologic features, degree of differentiation, and associations with lichen planus, lichen sclerosus, and HPV guide the selection of conservative treatments or surgical excision.

The pattern recognition receptors, complement system, inflammasomes, antimicrobial peptides, and cytokines are innate immunity soluble factors. They sense, either directly or indirectly, the potential threats and produce inflammation and cellular death. High interest in their modulation has emerged lately, acknowledging they are involved in many cutaneous inflammatory, infectious, and neoplastic disorders. We extensively reviewed the implication of soluble factors in skin innate immunity. Furthermore, we showed which molecules target these factors, how these molecules work, and how they have been used in dermatological practice. Cytokine inhibitors have paved the way to a new era in treating moderate to severe psoriasis and atopic dermatitis.

Introduction: Skin metastases arise in 10% of cancer patients, but standardized dermoscopy diagnostic criteria for skin metastases remain poor. This study's objective was to analyze the dermoscopy features of skin metastases from advanced systemic and cutaneous cancers.Methods: A retrospective study on 715 dermoscopy images of skin metastases from 33 patients with various primary cancers (breast, ovary, melanoma, non-melanoma skin cancer, and chronic leukemia) attending two academic centers between 2013 and 2023 was performed. Four independent observers blindly analyzed patterns, colors, vessels, and elementary lesions for each metastasis (30 parameters in total).Results: The structureless white pattern was the most prominent indicator of cutaneous metastasis (81.26%, p < 0.001). Regardless of the primary tumor, colors pink, red, white, and tan were identified. Elementary lesions were infrequent, except for melanoma metastases that displayed dots (13.23%) and globules (11.11%). Breast cancer metastases presented: blue (41.48%) and red (34.32%) colors, irregular vessels (13.58%), and a blue-naevus pattern (22.22%). Melanoma metastases displayed: a blue-naevus pattern (61.38%), a blue color (85.71%), and a structureless-blue combination pattern (79.37%). Non-melanoma skin cancer metastases were characterized by vascular (42.11%) and angioma-like (31.58%) patterns, pink (57.89%) and red (57.89%) colors, irregular (57.89%), thin hairpin (47.37%), comma (47, 37%), and thick hairpin (26, 32%) vessels and a red, white and irregular vessels combination pattern (52, 63%). A pink structureless combination pattern was frequent (61.05%) in chronic leukemia metastases. Ovarian cancer metastases displayed a white and tan structureless combination pattern (100%) and frequently had dotted vessels (42.85%).Conclusion: Papules and nodules with a white structureless pattern suggest skin metastases, regardless of the primary tumor. A blue structureless lesion is indicative of melanoma metastasis and a vascular pattern with irregular vessels indicates a non-melanoma skin cancer metastasis. Dermoscopy stands as a reliable non-invasive diagnostic method for suspected cutaneous metastases in patients with a known cancer history.