Gain-of-function human UNC93B1 variants cause systemic lupus erythematosus and chilblain lupus.

UNC93B1 is a transmembrane domain protein mediating the signaling of endosomal Toll-like receptors (TLRs). We report five families harboring rare missense substitutions (I317M, G325C, L330R, R466S, and R525P) in UNC93B1 causing systemic lupus erythematosus (SLE) or chilblain lupus (CBL) as either autosomal dominant or autosomal recessive traits. As for a D34A mutation causing murine lupus, we recorded a gain of TLR7 and, to a lesser extent, TLR8 activity with the I317M (in vitro) and G325C (in vitro and ex vivo) variants in the context of SLE. Contrastingly, in three families segregating CBL, the L330R, R466S, and R525P variants were isomorphic with respect to TLR7 activity in vitro and, for R525P, ex vivo. Rather, these variants demonstrated a gain of TLR8 activity. We observed enhanced interaction of the G325C, L330R, and R466S variants with TLR8, but not the R525P substitution, indicating different disease mechanisms. Overall, these observations suggest that UNC93B1 mutations cause monogenic SLE or CBL due to differentially enhanced TLR7 and TLR8 signaling.

Diagnosis and management of COVID toes in outpatients: a case report.

BACKGROUND: Since the beginning of the coronavirus disease 2019 pandemic, the most common skin lesions observed due to infection with the severe acute respiratory syndrome coronavirus 2 are pseudochilblains (or coronavirus disease toes). However, this pathology remains infrequent and difficult to diagnose, as no specific test exists. CASE PRESENTATION: Two Caucasian women, 30 and 22 years old, presented to our General Medicine Unit with perniosis lesions on the feet during the first two waves of the coronavirus disease 2019 pandemic. They did not have respiratory or general symptoms of severe acute respiratory syndrome coronavirus 2 infection, the reverse transcription polymerase chain reaction on nasopharyngeal swabs was negative, and the serology was positive only in the first case. The clinical presentation differed for the two cases, as the second patient suffered from swelling and burning after cold application. The diagnosis was based on clinical presentation, temporality, exclusion of other differential diagnoses, and blood test results (positive serology in the first case and high level of CXCL13 and VEGF in the second), supported by current literature. Lesions resolved spontaneously in the first patient. The second case was hospitalized for pain management and received corticosteroid therapy with resolution of the symptoms. CONCLUSION: These two cases with different clinical presentations illustrate the diagnostic approach to coronavirus disease 2019, a challenging disease with diverse manifestations, including, in some cases, coronavirus disease toes. We present a literature review that illustrates the progression of scientific research. Skin lesions associated with coronavirus disease 2019 infection could be the expression of an important interferon type 1 response and should be considered in the differential diagnosis in a primary care setting.

Early Cutaneous Manifestations of COVID-19: A Systematic Review and Public Health Implications.

INTRODUCTION: Cutaneous manifestations before other symptoms have great potential for early COVID-19 diagnosis to prevent surge. METHODS: We conducted a search of PubMed and Embase databases through April 11, 2021 to include 39 studies reporting skin manifestations occurring prior to any other COVID-19 symptoms in laboratory-confirmed cases. RESULTS: Ninety-seven patients were included. Urticarial (24.7%) and maculopapular (22.7%) lesions were most common, followed by pernio (17.5%), vesicular (14.4%), papulosquamous (8.2%), and purpuric (5.1%) lesions. Cutaneous to systemic symptom latency ranged from 2 to 20 days in cases that reported it (26%), while skin lesions were the only presentation in 23 cases (23.7%). Skin lesions were the only COVID-19 manifestation in 58.8% of pernio, 40% of vesicular, 16.6% of urticarial, 18.2% of maculopapular, and 12.5% of papulosquamous presymptomatic cases. Although sample size is limited, all purpuric cases developed other symptom(s) later. CONCLUSIONS: Pernio and purpuric lesions have been well-associated with COVID-19, but papulosquamous, vesicular, mild maculopapular, and urticarial lesions can easily be dismissed as unrelated to COVID-19. Pernio lesions are thought to be related to strong immune response and low contagiousness, while purpuric and vesicular cases are speculated to be related to higher SARS-CoV2 viral load, severity, and contagiousness. All rashes, even without other symptoms, should necessitate high level of suspicion for isolation or contact tracing.

Chilblain lupus with nail involvement: a case report

Chilblain lupus is a rarely manifested variant of chronic lupus. Its appearance can be sporadic or hereditary associated with an autosomal dominant mutation. The diagnosis is clinical and histopathological. The case is presented of a patient with systemic lupus erythematosus presenting with chilblain lupus and nail involvement, despite the use of antimalarials and immunomodulators.

La perniosis lúpica es una variante del lupus crónico que se manifiesta con poca frecuencia, su aparición puede ser esporádica o hereditaria, asociada con una mutación autosómica dominante, en tanto que su diagnóstico es clínico e histopatológico. Se reporta el caso de una mujer con lupus eritematoso sistémico con manifestación de perniosis lúpica y compromiso ungueal, a pesar del uso de antimaláricos e inmunomoduladores.

Perniosis idiopática: reporte de un caso y revisión de la literatura / Chilblains: report of a case and literature review

Pernio (chilblains) is an inflammatory condition classically characterized by localized erythema and swelling of acral sites upon exposure to cool and damp conditions. It is reported a case of a 59-year-old otherwise healthy woman with acute primary perniosis. She had a 3-day history of lesions on the toes brought on by cold, damp weather. On initial presentation, a biopsy sample was taken of a hallux lesion, and the patient was given a trial course of oral pentoxifylline, topical corticoid and nifedipine therapy. Follow-up at 2 weeks showed complete relief of symptoms and the biopsy results confirmed the diagnosis. Pentoxifylline therapy has been shown to be effective and should be considered the standard of care in the treatment of perniosis along with conservative environmental measures.The etiology and pathogenesis of perniosis are reviewed and discussed, as well as differential diagnoses and treatment options. (AU)

Chilblains in Turkey: a case-control study

BACKGROUND: Chilblains are rather common in winter months in our country. OBJECTIVES: Determination of demographical and clinical characteristics of patients presenting with chilblains in Diyarbakir, Turkey. Evaluation of body mass index (BMI) as risk factor for development of chilblains. METHODS: Sixty-nine patients who were diagnosed as chilblains at our outpatient clinics were included in this study. No exclusion criteria were sought. Demographical data including height and weight and answers to questions related to personal history were recorded. A control group consisting of 108 controls were chosen from among patients presenting with complaints of hair loss. Statistical analyses were conducted using SPSS 17.0. RESULTS: Of the 69 patients with chilblains, 45 (65.2%) were females and 24 (34.8%) were males. Mean age (±SD) of the patients was 21±9. 71.2% of the patients complained of itching, 51.6% of pain, 31.3% of burning in the lesions. 61.3% of the patients reported recurrence of the lesions every winter season. Mean BMI of the patients was 20.5±2.9. Mean BMI of the controls was 22.4±3.7 and the difference was statistically significant (p=0.01). CONCLUSIONS: Low BMI may be a risk factor contributing to development of chilblains in persons exposed to cold weather conditions. Apart from external factors, there seems to be a personal tendency to develop lesions, as many patients report recurrences every year. Diagnosis of chilblains requires wariness, as history of cold exposure may not be evident. .

Case for diagnosis / Caso para diagnóstico

Chilblains are an inflammatory skin condition that develops following exposure to the cold. They consist of pruritic and/or painful erythematous-to-violaceous acral lesions and are the result of an abnormal vascular response to exposure to the cold. This benign condition is common in southern Brazil, particularly in Rio Grande do Sul where climatic conditions, together with cultural and economic aspects, facilitate the development of these sores.

Eritema pérnio é uma condição inflamatória da pele que ocorre após exposição ao frio e se manifesta com lesões eritêmato-violáceas, pruriginosas e dolorosas nas extremidades. Ocorre devido a uma resposta vascular alterada à exposição ao frio. Esta condição benigna é frequente na região sul do Brasil, especialmente no Rio Grande do Sul, onde as características clínicas, associadas a aspectos culturais e econômicos, promovem o desenvolvimento do eritema pérnio.

Eritema pérnio na faixa etária pediátrica / Chilblains in pediatrics

Os autores apresentam 5 casos com eritema pérnio da população de 5079 pacientes acompanhados na Unidade de Reumatologia Pediátrica doInstituto da Criança por um período consecutivo de 25 anos. Destes, 4 eram primários e um secundário ao lúpus eritematoso sistêmico juvenil. Todos apresentaram lesões cutâneas com acometimento de extremidades associadas às baixas temperaturas ambientais. O tratamento principal foi orientação de aquecimento das extremidades, utilização de luvas e meias e uso de nifedipina nos casos refratários.

The authors show 5 cases with chilblains from the populations of 5079 patients followed in the Pediatric Rheumatology Unity of the Instituto da Criança for a consecutive a period of 25 years. From these, 4 were primary and one was secondary to juvenile systemic lupus erytematosus. All of them had cutaneous lesions with involvement of extremities, associated at low environmental temperature. The main treatment was the orientation with warming of the extremities, utilization of gloves and socks, and nifedipine in the refractory cases...

Eritema pernio y vasculitis linfocítica de los pabellones auriculares: reporte de dos casos / Chuildblain and lymphocytic vasculitis of ears: report of two cases

Se reportan dos casos de eritema pernio, muy similares clínicamente, que afectan los pabellones auriculares con deformaciones cicatrizales por exposición al frío intenso. La vasculitis linfocítica resulta histológicamente un patrón común en ambos casos. Se revisa además la etiopatogenia, los diagnósticos diferenciales y las medidas terapéuticas.

Perniosis / Perniosis

Perniosis, pernio o sabañones, son lesiones inflamatorias localizadas, causadas por exposición continua al frío por encima del punto de congelación. Esta condición se ha descrito con mayor frecuencia en Inglaterra y al noroccidente de Europa, en donde no es costumbre el uso de sistemas de calefacción central en las casas. En cambio es menos frecuente en climas fríos en donde los sistemas de calefacción y el uso de ropa abrigada son esenciales. Las lesiones pernióticas también han sido descritas asociadas a lupus eritematoso, en 1888Hutchinson describe lesiones eritematosas inducidas por el frió, como un subtipo de lupus eritematoso cutáneo. Este artículo hace una revisión de la literatura acerca de la perniosis idiopática y la asociada a lupus eritematoso...

Eritema pernio en dos gemelas de ocho meses de vida / Chillblains in two tween sisters eigth months old

Se comunican 2 pacientes gemelas, de ocho meses de vida, que presentan lesiones maculares eritematovioláceas localizadas en el dorso y regiones laterales de los pies, con edema de los dedos. Se realizan los estudios histopatológicos que son compatibles con eritema pernio, entidad que se diagnostica con poca frecuencia en lactantes

Lupus eritematoso: formas infrecuentes / Lupus erythematosus: uncommon manifestations

La piel está comprometida en la mayoría de los pacientes con lupus eritematoso. Las lesiones cutáneas más frecuentes son el rash malar, la fotosensibilidad, la alopecia, lupus discoide, lesiones en mucosas, pigmentación, vasculitis, fenómeno de Raynaud y urticaria. Menos frecuentemente los pacientes con lupus pueden desarrollar variantes clínicas inusuales tales como lupus eritematoso ampollar, lupus pernio, lupus eritematoso simil eritema gyrate y lesiones simil-eritema multiforme (síndrome de Rowell). Presentamos cinco pacientes con estas manifestaciones poco frecuentes. El reconocimiento de esta presentación es necesaria para un diagnóstico y tratamiento precoz y adecuado

Perniosis: Estudio clinico e histologico de 5 casos / Perniosis: Histological and Clinical study of 5 cases

Incluimos en este trabajo 5 casos de perniosis(2 superficiales,2 profundas,1 mixta)observados durante el invierno de 1990 en nuestro servicio. Clinicamente se presentaron como maculas o pequenias placas dolorosas de coloracion rojo-violacea localizada en miembros inferiores(4 casos) y cara (1 caso). La histologia revelo la tipica angeitis linfocitaria con edema de la pared vascular. Referimos otras variantes histologicas y consideramos sus principales diagnosticos diferenciales