A Rare Post-infectious Rash: Pityriasis Rubra Pilaris After COVID-19 Infection.

Pityriasis rubra pilaris (PRP) is a rare papulosquamous skin disorder that often presents with erythematous follicular-based hyperkeratotic papules that can become confluent and lead to erythroderma and electrolyte and thermoregulatory imbalances resulting from increased tissue perfusion and skin barrier breakdown. Due to this condition being uncommon, many specialties outside of dermatology are unfamiliar with this entity which poses unique diagnostic and management challenges. This case report involves a 55-year-old woman who presented to the emergency room with erythroderma secondary to PRP. It highlights the relevance of PRP in the context of in-hospital management by presenting the patient's clinical profile, diagnostic workup, and treatment plan. By emphasizing the distinctive clinical features and natural course of the disease, this report aims to enhance the understanding of this uncommon inflammatory skin condition.

Dissecting the human leptomeninges at single-cell resolution.

Emerging evidence shows that the meninges conduct essential immune surveillance and immune defense at the brain border, and the dysfunction of meningeal immunity contributes to aging and neurodegeneration. However, no study exists on the molecular properties of cell types within human leptomeninges. Here, we provide single nuclei profiling of dissected postmortem leptomeninges from aged individuals. We detect diverse cell types, including unique meningeal endothelial, mural, and fibroblast subtypes. For immune cells, we show that most T cells express CD8 and bear characteristics of tissue-resident memory T cells. We also identify distinct subtypes of border-associated macrophages (BAMs) that display differential gene expressions from microglia and express risk genes for Alzheimer's Disease (AD), as nominated by genome-wide association studies (GWAS). We discover cell-type-specific differentially expressed genes in individuals with Alzheimer's dementia, particularly in fibroblasts and BAMs. Indeed, when cultured, leptomeningeal cells display the signature of ex vivo AD fibroblasts upon amyloid-ß treatment. We further explore ligand-receptor interactions within the leptomeningeal niche and computationally infer intercellular communications in AD. Thus, our study establishes a molecular map of human leptomeningeal cell types, providing significant insight into the border immune and fibrotic responses in AD.

A prolonged outbreak of Salmonella Montevideo infections associated with multiple locations of a restaurant chain in Phoenix, Arizona, 2008.

An outbreak of Salmonella serotype Montevideo infections associated with multiple locations of restaurant chain A in Phoenix, AZ, was identified in July 2008. One infected individual reported eating at a chain A catered luncheon where others fell ill; we conducted a cohort study among attendees to identify the vehicle. Food and environmental samples collected at six chain A locations were cultured for Salmonella. Restaurant inspection results were compared among 18 chain A locations. Routine surveillance identified 58 Arizona residents infected with the outbreak strain. Three chain A locations, one of which catered the luncheon, were named by two or more case patients as a meal source in the week prior to illness onset. In the cohort study of luncheon attendees, 30 reported illness, 10 of which were later culture confirmed. Illness was reported by 30 (61%) of 49 attendees who ate chicken and by 0 of 7 who did not. The outbreak strain was isolated from two of these three locations from uncooked chicken in marinade, chopped cilantro, and a cutting board dedicated to cutting cooked chicken. Raw chicken, contaminated before arrival at the restaurant, was the apparent source of this outbreak. The three locations where two or more case patients ate had critical violations upon routine inspection, while 15 other locations received none. Poor hygiene likely led to cross-contamination of food and work areas. This outbreak supports the potential use of inspections in identifying restaurants at high risk of outbreaks and the need to reduce contamination of raw products at the source and prevent cross-contamination at the point of service.

Diagnosing Pemphigus Foliaceus: A Rare Blistering Disease Masquerading as a Common Dermatologic Disorder.

Pemphigus foliaceus (PF) is an autoimmune dermatologic disease that typically presents with painful, superficial blisters that evolve into scaling erosions in a seborrheic distribution. This case study intends to demonstrate that due to the relative scarcity of the disease and its distribution on the body, PF can easily be misdiagnosed. We present a 43-year-old African American male that presented to the dermatology clinic with an 18-month history of non-pruritic, violaceous, scaling patches and plaques most prominent on the malar cheeks, upper chest and upper back. He had been evaluated at an outside hospital with a high suspicion for cutaneous lupus erythematosus (CLE) and seborrheic dermatitis. However, repeated biopsies revealed non-specific spongiotic dermatitis, not consistent with CLE or seborrheic dermatitis. Over the subsequent months, he received treatment for both conditions without improvement in his symptoms. When he was referred to our dermatology clinic, repeat biopsies were obtained which demonstrated acantholysis and dyskeratosis in the granular layer, consistent with PF. Direct immunofluorescence revealed intercellular IgG staining most prominent in the epidermis, also consistent with PF. Finally, enzyme-linked immunosorbent assay for anti-desmoglein 1 returned positive, confirming the diagnosis. Upon review of the previous biopsies, focal areas of acantholysis and dyskeratosis were noted in the granular layer, which would have pointed away from a diagnosis of CLE or seborrheic dermatitis if PF was included in the clinical differential diagnosis. This case serves as a reminder that when there is a discrepancy in clinical-pathologic correlation, it is important to revisit the case and consider other pathologies.

Diagnosing IgA Vasculitis in the Active Duty Population: The Importance of Early Diagnosis and Proper Biopsy Site Selection.

Immunoglobulin A associated vasculitis (IgAV), formerly called Henoch-Schönlein purpura, is a small vessel vasculitis which typically presents with upper and lower extremity palpable purpura and abdominal pain. It is the most common vasculitis in children, and is less common in adults. However, newer evidence suggests the incidence within the adult population is higher than previously reported. This case study demonstrates an adult military recruit presenting with new onset IgAV shortly after basic training. He noted a preceding upper respiratory tract infection, which is a common finding in those presenting with IgAV. The diagnosis was made by clinical findings, histopathological results and direct immunofluorescence. Adults tend to develop more necrotic and bullous lesions when compared with children. This can skew histopathology and direct immunofluorescence. There is no clear consensus in current literature for whether to obtain lesional or perilesional biopsies. Such recommendations could be particularly advantageous for adults given the abnormal lesions. This case study addresses the incidence of IgAV within the adult population, diagnostic criteria, long-term sequalea of IgAV, and the importance of a proper biopsy sight when making the diagnosis.

Sandfly fever in Afghanistan-a sometimes overlooked disease of military importance: a case series and review of the literature.

Sandfly fever, sometimes known as pappataci fever or Phlebotomus fever, is a vector transmitted viral illness with a history of affecting naïve military formations that travel through or fight in areas in which the infection is endemic. We present a series of 4 hospitalized cases of sandfly fever (2 presumptive, 2 laboratory confirmed) that were admitted to a Role 3 hospital in Afghanistan for evaluation and treatment following medical evacuation from a forward area for marked fevers and malaise. Laboratory evaluation of these cases was significant for leukopenia and thrombocytopenia, consistent with historical descriptions of sandfly fever. In the correct geographic and clinical setting, the finding of mild leukopenia among a cluster of febrile patients should prompt the clinician to at least consider a diagnosis of sandfly fever. A cluster investigation conducted by preventive medicine personnel identified numerous other presumed cases of sandfly fever in this forward special operations camp. Response efforts emphasized enforcement of standard vector-borne disease control measures by operational leadership in order to limit effect on tactical operations. We review historical instances of sandfly fever affecting military operations, and present a review of clinical presentation, transmission, management, and prevention.