Peritumoral Clefts in Basal Cell Carcinoma: Matrix Metabolism and Primary Cilium.

The phenomenon of tissue retraction, characterized by peritumoral spaces or clefts, is prominent in basal cell carcinoma (BCC) tumors, yet its underlying mechanisms remain unclear. Proposed factors include changes in cell structures, enzymatic activity, and alterations in the Hedgehog (Hh) signaling pathway. This article discusses these factors and proposes that structural changes in BCC cells' primary cilia may contribute to matrix alterations, leading to the formation of peritumoral clefts. Further research is needed to confirm these hypotheses and understand BCC's unique growth patterns.

Erythrasma: Pathogenesis and Diagnostic Challenges.

Erythrasma is a common chronic superficial bacterial infection caused by Corynebacterium minutissimum, a lipophilic, diphtheroid, filamentous, gram-positive bacillus and normal inhabitant of the skin flora. Commonly found in intertriginous spaces, this bacterium releases a porphyrin that causes lesions to fluoresce under a Wood's lamp, aiding diagnosis. Despite its clinical relevance, the pathogenesis remains understudied. We present a case of a 43-year-old woman with a history of hypertension, type 2 diabetes mellitus, and obesity who exhibited an erythematous eczematous plaque with characteristic coral-red fluorescence under Wood's lamp. The diagnosis was confirmed through negative skin scrapings for candidiasis and dermatophytosis. A two-week course of topical clindamycin resulted in complete resolution. Given the condition's frequent coexistence with other pathologies, accurate diagnosis and effective treatment are essential. Topical treatments are usually more convenient. The hypothesis that hydrophobic and lipophilic interactions in intertriginous areas contribute to the pathogenesis of erythrasma requires further experimental validation.

Eczema Herpeticum: Clinical Insights and Pathogenesis Hypotheses on Basolateral Adhesion Proteins.

Eczema herpeticum (EH) is a severe viral complication caused by the herpes simplex virus (HSV) that occurs in individuals with compromised skin barriers, such as those with atopic dermatitis (AD). EH is characterized by the rapid spread of HSV across skin lesions, potentially leading to systemic involvement. Although commonly observed in the context of AD, EH can also arise in various dermatological conditions, necessitating prompt recognition and management by healthcare providers. This case report details the diagnosis and treatment of EH in a five-year-old girl with a history of AD who presents with fever and painful skin lesions. Despite the absence of confirmatory tests initially, a positive IgM anti-HSV-1 serology, combined with clinical presentation, supported the diagnosis of EH. The patient received intravenous aciclovir, resulting in significant improvement within 48 hours. This case highlights the importance of early diagnosis and treatment, particularly when confirmatory tests are not available. The report discusses the clinical presentation of EH, which includes vesicular lesions, fever, and rapid progression. The differential diagnosis includes chickenpox, impetigo, eczema vaccinatum, and contact dermatitis. Understanding the epidemiology and pathogenesis of EH, especially in relation to AD, is crucial for effective management. The case also introduces a novel hypothesis linking structural protein alterations to immune dysfunction in EH, suggesting a need for further research. Acyclovir remains the gold standard for treating EH, and timely intervention is essential. This case underscores the necessity of a diagnostic algorithm in the absence of guidelines and highlights the role of IgM serology and clinical judgment in managing suspected EH cases.

Retrospective Analysis of a Seborrheic Keratosis-Like Melanoma on the Head.

We present a clinical case of a 50-year-old female initially suspected of seborrheic keratosis but later diagnosed with melanoma through biopsy. This case highlights the challenges in distinguishing between these two conditions and emphasizes the importance of accurate diagnosis. Overdiagnosis of malignancy in seborrheic keratosis cases and the accurate identification of melanoma through dermoscopy are discussed. Further research is needed to explore potential mechanistic connections between seborrheic keratosis and melanoma.

Seborrheic Pemphigus: A Misunderstood Variant of Pemphigus Foliaceus.

Seborrheic pemphigus (SP) represents a localized and superficial form of pemphigus foliaceus (PF) often mistaken for other dermatological conditions such as seborrheic dermatitis (SD) due to clinical similarities. Additionally, SP may be conceptually confused with pemphigus erythematosus (PE) due to historical terminology and overlapping clinical features. We present a case study of a 38-year-old female initially diagnosed with SD but later identified as SP through detailed clinical and histopathological analysis. We discuss the challenges in accurately diagnosing SP, emphasizing the importance of distinguishing it from PE and other acantholytic dermatoses. Furthermore, we highlight the effectiveness of topical treatment in managing SP, contrary to the systemic therapy often required for PE. Our findings underscore the necessity for further research to optimize management strategies for SP and emphasize the significance of precise terminology in clinical practice and research.

Acquired Bilateral Nevus of Ota-Like Macules: A Case Report.

Facial melanoses (FM) present complex diagnostic and therapeutic challenges, particularly in the setting of dermal melanocytoses (DM). We present a case that illustrates these challenges as it does not fit within existing classification frameworks. Initially considered as Ota nevus, characterized by blue or dark pigmentation and scleral involvement, histopathological findings suggested acquired bilateral nevus of Ota-like macules (ABNOM). While ABNOM, more common in Asians, rarely affects the sclera or children, recent studies indicate that it may be underdiagnosed in these groups. Differential diagnosis ruled out other FM causes due to mucosal involvement. Correct classification is essential for epidemiological accuracy and treatment decisions, especially given varying responses to Q-switched laser therapy and melanoma risks associated with Ota nevus and ABNOM. While the pathogenesis remains unclear, a two-hit model involving shared melanoma mutations in melanocytes has been proposed and warrants further molecular study.

An Immune-Based Therapeutical Approach in an Elderly Patient With Fixed Cutaneous Sporotrichosis.

Sporotrichosis is a subcutaneous fungal infection caused by thermally dimorphic fungi from the Sporothrix genus, primarily prevalent in tropical regions of Latin America, Africa, and Asia. Mexico's Jalisco state is an endemic hotspot with a remarkable prevalence rate of 54.4%. Clinical presentation varies based on immune status and virulence. The most common form is cutaneous-lymphangitic (67%), with fixed cutaneous cases accounting for 28%. This case study explores a traditional therapeutic approach for fixed cutaneous sporotrichosis but introduces a distinct immunological perspective.

Ulcerative Unilateral Tinea Manuum Caused by Nannizzia gypsea.

Dermatophytes, fungi specialized in keratin degradation, are key agents in skin infections, commonly referred to as tineas. Tinea manuum, affecting the hands, typically presents in noninflammatory or inflammatory forms, with ulcerative manifestations rarely reported. Nannizzia gypsea, a relatively uncommon cause of tineas, exhibits variable prevalence influenced by geographic factors. This study investigates a case of Ulcerative Unilateral Tinea Manuum caused by N. gypsea, aiming to explore the differential diagnosis, pathogenesis, and management. A 23-year-old female from the Yucatan Peninsula presented with an ulcerated lesion on her left hand. Initially suspected as Leishmaniasis, subsequent examination revealed tinea manuum. The study discusses differential diagnoses, highlighting the rarity of ulcerative presentations in dermatophytosis, and explores potential pathogenic mechanisms. This case underscores the importance of considering dermatophytes in ulcerative skin lesions and suggests a comprehensive diagnostic approach, particularly in endemic regions.

Tinea Capitis Kerion Type in Three Siblings Caused by Nannizzia Gypsea.

This case report describes a rare occurrence of tinea capitis kerion type caused by Nannizzia gypsea in three siblings. The clinical presentation included pseudo-alopecic plaques with a dirty appearance, erythema, and honey-like crusts. A direct examination revealed ecto-endothrix parasitization in the hair shaft. Shared use of a comb among the siblings was suspected as the mode of transmission. Treatment with oral terbinafine resulted in a complete resolution. Systematic epidemiological surveys on N. gypsea tinea infections are scarce, and preliminary data from our center indicated a higher prevalence. The literature review identified five reported cases of N. gypsea-induced tinea capitis.

Microsporum canis-Induced Tinea Capitis: A Rapid Screening Algorithm.

Tinea capitis is a common fungal infection of the scalp, primarily affecting children, and caused by fungi like Trichophyton and Microsporum. Its pathogenesis is influenced by both host-specific and environmental factors, resulting in various clinical presentations including hair loss and scaling of the scalp. We present the case of an eight-year-old male with tinea capitis, characterized by itching and hair loss in the occipital area. Examination revealed characteristic findings on trichoscopy, and direct examination of hair confirmed parasitization. Treatment with terbinafine was initiated, leading to the resolution of symptoms. Epidemiological variations in the etiology of tinea capitis exist globally, with Trichophyton predominating in some regions and Microsporum in others. Trichoscopy is a valuable diagnostic tool for differentiating fungal infections, guiding treatment decisions. Despite the efficiency of direct skin and hair examination, the common occurrence of tinea and the lack of mycological centers in many clinics pose challenges. To address this, we propose integrating trichoscopy and epidemiological and clinical data for a quick in-office decision tool.

Sporadic Kaposi Sarcoma Following a COVID-19 Vaccine: Mere Coincidence or Something More?

In this case report, we present a distinctive occurrence of classic Kaposi sarcoma (KS) in an individual of Latin origin, emerging seven days following the administration of the third dose of the ChAdOx1 nCoV-19 (AstraZeneca) vaccine. The progression of KS continued over two months, culminating in the development of a tumor. Given the absence of prior reports on KS development post-COVID-19 vaccination, the primary aim of this report is to explore the potential relationship between the ChAdOx1 nCoV-19 vaccine, reactivation of Kaposi sarcoma-associated herpes virus, and the subsequent onset of KS.

Acro-Ischemia Associated With SARS-CoV-2: A Case Report.

COVID-19 is known to cause various cutaneous lesions, including acro-ischemic lesions (AIL), which are associated with poor prognosis. Anticoagulant therapy has shown positive responses in AIL patients. However, in this case study, we present a fatal AIL case despite anticoagulant therapy. We propose different treatment approaches based on the limited current data on acro-ischemia pathogenesis related to SARS-CoV-2. The clinical case involved a 59-year-old male with severe COVID-19 symptoms, including acrocyanosis and right hemiparesis. Despite receiving anticoagulant therapy, the patient's condition worsened, leading to necrosis in the left foot. The discussion focuses on the high-risk nature of AIL, the potential link between angiotensin-converting enzyme 2 (ACE2) receptors and vasculitis or thromboembolic manifestations, and the role of immune clots in AIL pathogenesis. Behçet syndrome is referenced as a model of inflammation-induced thrombosis, guiding the suggestion for immunosuppressant-based treatment in addition to anticoagulants. Additionally, three substances, N-acetyl cysteine, sulodexide, and hydroxychloroquine, are proposed.

Tinea Nigra: Clinical and Diagnostic Guidance.

Tinea nigra is a rare superficial fungal infection characterized by asymptomatic, unilateral, well-defined brown to black macules predominantly affecting the palms and soles. Diagnosis is often challenging due to its rarity and resemblance to other pigmented lesions. This report presents a clinical case, a diagnostic algorithm, and treatment recommendations, emphasizing the role of thorough examination and questioning. We describe the case of a 64-year-old woman of Amerindian (Maya) heritage from Yucatan, Mexico, who presented with a three-month history of a slowly growing dark spot on her left palm. The lesion was asymptomatic, non-scaling, and non-palpable. Palmar skin scrapings, prepared with KOH, revealed pigmented yeast and hyphae, leading to a diagnosis of tinea nigra. Following treatment with topical ketoconazole, the patient's lesions completely resolved at the one-month follow-up. The cultivation of scales confirmed the presence of Hortaea werneckii. Our findings highlight the importance of considering tinea nigra in the differential diagnosis of pigmented lesions on acral surfaces. We propose a diagnostic algorithm to aid healthcare professionals in recognizing this uncommon condition and recommend treatment protocols that effectively resolve the infection within two weeks. This case underscores the necessity for increased awareness and accurate diagnosis of tinea nigra, particularly in non-endemic regions.

Chronic Spontaneous Urticaria Following COVID-19 Vaccination: A Case Report and Discussion on Allergic Reactions and Vaccine Safety.

This case report examines a rare occurrence of chronic spontaneous urticaria (CSU) following the administration of the CoronaVac vaccine for COVID-19. The patient developed persistent urticarial lesions that appeared and disappeared over an extended period after receiving the vaccine. The diagnosis of CSU was supported by histopathological examination and the close temporal correlation between symptom onset and vaccination. The discussion focuses on the immune mechanisms involved in CSU, the potential triggers of allergic reactions to COVID-19 vaccines, and the importance of further research to identify specific allergenic components. This case underscores the need for vigilance in monitoring and reporting adverse events related to COVID-19 vaccination to ensure vaccine safety and optimize public health strategies.

Correction: Bullous Pilomatrixoma After COVID-19 Vaccination.

[This corrects the article DOI: 10.7759/cureus.32370.].

Basal Cell Carcinoma in the Periungual Region: A Rare Case and Pathogenesis Insights.

This case report presents a rare occurrence of basal cell carcinoma (BCC) in the periungual region of the thumb. BCC is the most common type of skin cancer, typically found in sun-exposed areas. The discussion explores the underlying pathogenesis mechanisms, including the role of ultraviolet exposure, the absence of pilosebaceous units, and the involvement of the sonic hedgehog (SHH) pathway. Understanding the complexities of BCC in atypical locations is essential for effective prevention and treatment strategies.

First Onset of IgA Vasculitis and Nephritis Following COVID-19 Vaccination.

The article presents a case of a 32-year-old male who developed IgA vasculitis (IgAV) and IgA vasculitis nephritis (IgAVN) after receiving the second dose of the AstraZeneca COVID-19 vaccine. IgAVN can be a rare side effect of COVID-19 vaccines. Healthcare providers should be aware of this potential adverse event, and promptly recognize and manage it. However, the benefits of vaccination in reducing the morbidity and mortality associated with COVID-19 far outweigh the risks of this rare adverse event.

Disseminated Cutaneous Mycobacterium chelonae Infection in an Immunocompetent Patient.

We present a case report on disseminated cutaneous Mycobacterium chelonae infection with a sporotrichoid pattern in an immunocompetent patient. The aim of this report is to contribute to the existing knowledge on the clinical presentation and management of this uncommon presentation.