Histopathology of persistent long COVID toe: A case report.

During the 2020 coronavirus (SARS-CoV-2) pandemic, several cutaneous lesions were identified, including pseudo-chilblain, vesicular, urticarial, maculopapular, and livedo/necrosis. A 59-year-old obese man with probable COVID-19 developed painful cyanosis with histopathologic capillary thrombosis of toes, and the cyanosis persisted for nearly 22 months. Shortly after initial exposure to family members with documented SARS-CoV-2, he developed upper respiratory symptoms, yet his anti-SARS-CoV-2 antibody and nasal swab RT-PCR tests were repeatedly negative. Two family members were hospitalized and one of them succumbed with documented SARS-CoV-2 pneumonia within 10 days of exposure. Biopsy specimen of the distal toe 16 weeks after initial exposure showed papillary dermal capillary thrombosis with endothelial swelling, telangiectasia, and peri-eccrine lymphocytic infiltrates resembling pernio. Overall, this is the first case of biopsy specimen of "long COVID toe" following presumed SARS-CoV-2 exposure, with a demonstration of thrombotic vasculopathy, toe cyanosis, and pernio-like pathology.

Post-vaccination COVID Toes (Chilblains) Exacerbated by Rituximab Infusion Suggests Interferon Activation as Mechanism.

Coronavirus disease (COVID) toes are pernio-like skin lesions associated with severe acute respiratory syndrome coronavirus 2. We observed pernio-like skin findings presenting after a Pfizer BioNTech vaccine, which significantly worsened after an infusion of rituximab. This suggests that the mechanism for COVID toes is interferon activation. Military providers may avoid unnecessary referrals for this self-limiting condition by anticipating this adverse effect.

An Autopsy Review: "COVID Toes".

ABSTRACT: "Severe acute respiratory syndrome coronavirus-2" (SARS-CoV-2) infection has variable described dermatologic manifestations. "COVID (coronavirus disease) toes" became a hallmark of the disease in young and largely asymptomatic patients, who may have negative test results for SARS-CoV-2. Pernio (chilblains)-like lesions are seen mostly in infected pediatric patients and are purple painful, frequently bilateral, ill-defined plaques with prominent inflammation on histological examination. In contrast to pernio-like presentation in children, critically ill adult patients with SARS-CoV-2 develop "purple" digits that may be sharply demarcated and may demonstrate asymmetric areas of ischemia. These 2 contrasting entities are sometimes grouped together as "COVID toes" due to some similarities in clinical appearance and presentation. Here, we summarize histopathologic examination from an autopsy, including the cutaneous lesions from the affected and normal contralateral toes and correlate them with systemic findings. In contrast to pernio-like lesions, the skin of the affected necrotic toes contained thrombi in vessels without prominent inflammation, suggestive of an embolic event. This is further supported by the clinical history of and autopsy findings of popliteal artery thrombus and multiple subsegmental pulmonary emboli. Our findings suggest that critically ill patients with SARS-CoV-2 have different pathological processes affecting skin at peripheral sites (ie, fingers, toes, ears, and nose), which may be due to thromboembolic events. The skin is a mirror of the body and skin pathology may shed light into overall pathogenesis of systemic illness and processes.

A clinicopathological description of COVID-19-induced chilblains (COVID-toes) correlated with a published literature review.

BACKGROUND: The abundance of publications of COVID-19-induced chilblains has resulted in a confusing situation. METHODS: This is a prospective single-institution study from 15 March to 13 May 2020. Thirty-two patients received PCR nasopharyngeal swabs. Of these, 28 patients had a thoracic CT-scan, 31 patients had blood and urine examinations, 24 patients had skin biopsies including immunohistochemical and direct immunofluorescence studies, and four patients had electron microscopy. RESULTS: COVID-19-induced chilblains are clinically and histopathologically identical to chilblains from other causes. Although intravascular thrombi are sometimes observed, no patient had a systemic coagulopathy or severe clinical course. The exhaustive clinical, radiological, and laboratory work-up in this study ruled-out other primary and secondary causes. Electron microscopy revealed rare, probable viral particles whose core and spikes measured from 120 to 133 nm within endothelium and eccrine glands in two cases. CONCLUSION: This study provides further clinicopathologic evidence of COVID-19-related chilblains. Negative PCR and antibody tests do not rule-out infection. Chilblains represent a good prognosis, occurring later in the disease course. No systemic coagulopathy was identified in any patient. Patients presenting with acral lesions should be isolated, and chilblains should be distinguished from thrombotic lesions (livedo racemosa, retiform purpura, or ischemic acral necrosis).

A Review of COVID-19 Chilblains-like Lesions and Their Differential Diagnoses.

GENERAL PURPOSE: To familiarize wound care practitioners with the differential diagnoses of chilblains-like lesions that could be associated with the complications of COVID-19. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant will:1. Identify the population most often affected by COVID toes.2. Select the assessments that help differentiate the various conditions that cause chilblains-like lesions.3. Choose appropriate treatment options for the various conditions that cause chilblains-like lesions.

This review article focuses on the pathogenesis, clinical features, and diagnostic testing of the common pathologies that can manifest as chilblains-like lesions. These differentials include "COVID toes," Raynaud phenomenon, acrocyanosis, critical limb ischemia, thromboangiitis obliterans, chilblains associated with lupus erythematosus, and idiopathic chilblains. The authors present a helpful mnemonic, ARCTIC, to assist clinicians in recognition and diagnosis.

Bilateral Chilblain-like Lesions of the Toes Characterized by Microvascular Remodeling in Adolescents During the COVID-19 Pandemic.

Importance: Chilblain-like lesions have been one of the most frequently described cutaneous manifestations during the COVID-19 pandemic. Their etiopathogenesis, including the role of SARS-CoV-2, remains elusive. Objective: To examine the association of chilblain-like lesions with SARS-CoV-2 infection. Design, Setting, and Participants: This prospective case series enrolled 17 adolescents who presented with chilblain-like lesions from April 1 to June 30, 2020, at a tertiary referral academic hospital in Italy. Main Outcomes and Measures: Macroscopic (clinical and dermoscopic) and microscopic (histopathologic) analysis contributed to a thorough understanding of the lesions. Nasopharyngeal swab, serologic testing, and in situ hybridization of the skin biopsy specimens were performed to test for SARS-CoV-2 infection. Laboratory tests explored signs of systemic inflammation or thrombophilia. Structural changes in peripheral microcirculation were investigated by capillaroscopy. Results: Of the 17 adolescents (9 [52.9%] male; median [interquartile range] age, 13.2 [12.5-14.3] years) enrolled during the first wave of the COVID-19 pandemic, 16 (94.1%) had bilaterally localized distal erythematous or cyanotic lesions. A triad of red dots (16 [100%]), white rosettes (11 [68.8%]), and white streaks (10 [62.5%]) characterized the dermoscopic picture. Histologic analysis revealed a remodeling of the dermal blood vessels with a lobular arrangement, wall thickening, and a mild perivascular lymphocytic infiltrate. SARS-CoV-2 infection was excluded by molecular and serologic testing. In situ hybridization did not highlight the viral genome in the lesions. Conclusions and Relevance: This study delineated the clinical, histologic, and laboratory features of chilblain-like lesions that emerged during the COVID-19 pandemic, and its findings do not support their association with SARS-CoV-2 infection. The lesions occurred in otherwise healthy adolescents, had a long but benign course to self-resolution, and were characterized by a microvascular remodeling with perivascular lymphocytic infiltrate but no other signs of vasculitis. These results suggest that chilblain-like lesions do not imply a concomitant SARS-CoV-2 infection. Ongoing studies will help clarify the etiopathogenic mechanisms.

Atypical cutaneous and musculoskeletal manifestation of SARS-CoV-2: 'COVID-19 toes' and spasticity in a 48-year-old woman.

Establishing accurate symptomatology associated with novel diseases such as COVID-19 is a crucial component of early identification and screening. This case report identifies an adult patient with a history of clotting dysfunction presenting with rare cutaneous manifestations of COVID-19, known as 'COVID-19 toes'', previously described predominantly in children. Additionally, this patient presented with possible COVID-associated muscle spasticity of the lower limbs, as well as a prolonged and atypical timeline of COVID-19 infection. The rare occurrence of 'COVID-19 toes'' in this adult patient suggests that her medical history could have predisposed her to this symptom. This supports the coagulopathic hypothesis of this manifestation of COVID-19 and provides possible screening questions for patients with a similar history who might be exposed to the virus. Additionally, nervous system complaints associated with this disease are rare and understudied, so this novel symptom may also provide insight into this aspect of SARS-CoV-2.

COVID toes: where do we stand with the current evidence?

BACKGROUND: Numerous of cases of chilblains have been observed, mainly in young subjects with no or mild symptoms compatible with COVID-19. The pathophysiology of these lesions is still widely debated and an association with SARS-CoV-2 infection remains unconfirmed. OBJECTIVES: This paper focus on the unresolved issues about these COVID toes and in particular whether or not they are associated with COVID-19. ARGUMENTS: The temporal link between the outbreak of chilblains and the COVID-19 pandemic is a first suggests a link between the two events. Positive anti-SARS-CoV/SARS-CoV-2 immunostaining on skin biopsy of chilblains seem to confirm the presence of the virus in the lesions, but lack specificity and must be interpreted with caution. Conversely, RT-PCR and anti-SARS-CoV-2 serology were negative in the majority of patients with chilblains. Therefore, SARS-CoV-2 infection can be excluded, with relative certainty, even after accounting for possible lower immunization in mild/asymptomatic patients and for some differences in sensitivity/specificity between the tests used. Some authors hypothesize that chilblains could be the cutaneous expression of a strong type I interferon (IFN-I) response. High production of IFN-I is suggested to be associated with early viral control and may suppress antibody response. However, the absence of other cutaneous or extracutaneous symptoms as observed in other interferonopathies raises unanswered questions. To date, a direct link between chilblains and COVID-19 still seems impossible to confirm. A more indirect association due to lifestyle changes induced by lockdown is a possible explanation. Improvement of chilblains when protective measures were adopted and after lifting of lockdown, support this hypothesis. CONCLUSION: Conflicting current evidence highlights the need for systematic and repeated testing of larger numbers of patients and the need for valid follow-up data that take into consideration epidemic curves and evolution of lockdown measures.

COVID Purpura (Toes) Case Series: A Chilblains-Like Vasculopathy.

ABSTRACT: Biopsies were taken from 4 patients who presented to their dermatologist with violaceous papules and plaques of the dorsal toes (COVID Toes) associated with varying degrees of severe acute respiratory syndrome coronavirus 2 exposure and COVID-19 testing. Major histopathologic findings were lymphocytic eccrine inflammation and a spectrum of vasculopathic findings to include superficial and deep angiocentric-perivascular lymphocytic inflammation, lymphocytes in vessel walls (lymphocytic vasculitis), endothelial swelling, red blood cell extravasation, and focal deposits of fibrin in both vessel lumina, and vessel walls. Interface changes were observed to include vacuolopathy and apoptotic keratinocytes at the basement membrane. Immunostains showed a dominant T-cell lineage (positive for T-cell receptor beta, CD2, CD3, CD5, and CD7). B-cells were rare and clusters of CD123-positive dermal plasmacytoid dendritic cells were observed surrounding eccrine clusters and some perivascular zones. The consistent perieccrine and vasculopathic features represent important pathologic findings in the diagnosis of COVID toes and are suggestive of pathogenetic mechanisms. Clinicopathologic correlation, the epidemiological backdrop, and the current worldwide COVID-19 pandemic favor a viral causation and should alert the physician to initiate a workup and the appropriate use of COVID-19 testing.

Case Report: Chilblains-like lesions (COVID-19 toes) during the pandemic - is there a diagnostic window?

The COVID-19 outbreak caused by the novel coronavirus, SARS-CoV-2, typically presents with symptoms including fever, cough, headache, myalgia, asthenia, anosmia, diarrhea, and sometimes pneumonia, which can be fatal.  Recently, new dermatologic findings have been described in association with the disease that can potentially be a distinguishing feature of infection. One such feature resembles chilblains and this case report represents a presentation of this feature with a 48-year-old female with violaceous lesions with surrounding pink erythema on her toes who tested negative for COVID-19.

Understanding the role that 'COVID toe' has in recognizing the potential extent of COVID-19 infections: a case study.

Dermatological manifestations have shown to be associated with COVID-19 infections. The numbers of papers have quadrupled within May 2020 alone. One particular cutaneous manifestation named pseudo chilblains (COVID toe), expressed mostly in otherwise asymptomatic younger patients, has had particular media attention. Public health bodies, on the other hand, have been slow to recognize it as a symptom. This article will be discussing two case studies to demonstrate the lack of public knowledge and of public health guidance associated with this symptom. We will further explore the use of COVID toe in the epidemiology of COVID-19 and its utility as a sign for total cases and contact tracing.

Going viral: A brief history of Chilblain-like skin lesions ("COVID toes") amidst the COVID-19 pandemic.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of the COVID-19 global pandemic, is notable for an expanding list of atypical manifestations including but not limited to coagulopathies, renal dysfunction, cardiac injury and a multisystem inflammatory syndrome in children. In addition, SARS-CoV-2 has been purportedly linked to multiple cutaneous manifestations, among them chilblain-like skin lesions, also known as "COVID toes." Driven in large part by social media, dermatologists around the world reported a dramatic increase in the frequency of chilblain-like diagnoses early in the COVID-19 pandemic, often in members of the same family. This phenomenon has been captured in a rapidly expanding medical literature. As of this writing, the chilblain-like presentation has been reported to occur predominantly in younger, minimally symptomatic patients and to emerge late in the COVID-19 disease course. Evidence of SARS-CoV-2 infection is not consistently found when these patients are evaluated by polymerase chain reaction. A robust antiviral immune response in young patients that induces microangiopathic changes has been posited as a mechanism. Herein we review the rapid evolution of the literature regarding chilblain-like skin lesions early in the COVID-19 global pandemic.