COVID-19: Findings in nuclear medicine from head to toe.

COVID-19 is a multisystemic disease, and hence its potential manifestations on nuclear medicine imaging can extend beyond the lung. Therefore, it is important for the nuclear medicine physician to recognize these manifestations in the clinic. While FDG-PET/CT is not indicated routinely in COVID-19 evaluation, its unique capability to provide a functional and anatomical assessment of the entire body means that it can be a powerful tool to monitor acute, subacute, and long-term effects of COVID-19. Single-photon scintigraphy is routinely used to assess conditions such as pulmonary embolism, cardiac ischemia, and thyroiditis, and COVID-19 may present in these studies. The most common nuclear imaging finding of COVID-19 vaccination to date is hypermetabolic axillary lymphadenopathy. This may pose important diagnostic and management dilemmas in oncologic patients, particularly those with malignancies where the axilla constitutes a lymphatic drainage area. This article aims to summarize the relevant literature published since the beginning of the pandemic on the intersection between COVID-19 and nuclear medicine.

Chilblain-like lesions (COVID-19 toes) have the same impact on family members than psoriasis systemically treated: insights from a case-control study targeting the pediatric population.

OBJECTIVE: COVID-19 toes represent the main dermatological COVID-19 cutaneous manifestation in pediatric patients. Its diagnosis exposes the whole family to social stigma and this aspect was not previously evaluated. PATIENTS AND METHODS: This was a multicenter, case-control, observational study that compared the family impact of COVID-19 toes vs. psoriasis (PsO). We enrolled 46 pediatric patients (23 with psoriasis and 23 with COVID-19 toes, age and gender matched) and their parents/caregivers that had to fill the Dermatitis Family Impact (DFI) questionnaire. RESULTS: DFI index did not differ significantly between both subgroups (p=0.48), and in psoriatic patients did not correlate with both Psoriasis Area Severity Index (PASI) (p=0.59) and itch-VAS (p=0.16). CONCLUSIONS: COVID-19 toes, a transitory dermatosis, exerted a similar impact/perturbation on family dynamics than PsO, a well-known stigmatizing, chronic inflammatory dermatosis.

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.

Not COVID Toes: Pool Palms and Feet in Pediatric Patients.

So-called COVID toes is probably the most publicized cutaneous manifestation of COVID-19. The parents of 4 patients pursued dermatology evaluation with concerns about COVID-19 infection in their children who presented with symmetric, focal, erythematous lesions of the hands or feet, or both. We elicited a history of extended time in swimming pools for the 4 patients that was associated with COVID-19 restrictions during summer months of the pandemic and recognized findings of frictional and pressure-induced erythema and scaling, leading to a diagnosis of pool palms and feet-an extension of pool palms. It is important to recognize this diagnosis and provide reassurance to the patients and caregivers because the condition warrants no notable workup or therapeutic intervention.

COVID toes: Pernio-like lesions.

More than 40 million people have been infected with the severe acute respiratory syndrome coronavirus 2 since the first infection was reported in December 2019 from Wuhan, China. Multiple reports of cutaneous manifestations of the virus have been described, including a pernio-like eruption, recently termed "COVID toes." We have reviewed the published case series on "COVID toes" in addition to studies identifying possible pathogenic mechanisms behind the eruption.

COVID Toes: Concurrent Lower Limb Arterial and Venous Thromboembolism in a Patient with COVID-19 Pneumonitis Presenting with Foot Ischaemia.

We present a 74-year-old gentleman, who presented with foot ischaemia requiring bilateral amputation in the absence of radiological signs of occlusive peripheral arterial disease. He was found to have COVID-19 pneumonitis and concurrent arterial and venous thromboemboli despite no initial respiratory symptoms or signs, nor pre-existing risk factors for cardiovascular disease. Patients who present with foot ischaemia with or without respiratory symptoms or signs warrant a high index of suspicion for COVID-19 infection, particularly in those with no predisposing risk factors.

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.

"COVID toes": A meta-analysis of case and observational studies on clinical, histopathological, and laboratory findings.

BACKGROUND: Coronavirus disease (COVID-19) is related to several extrapulmonary disorders; however, little is known about the clinical, laboratory, and histopathological characteristics of pernio-like skin lesions associated with COVID-19 infection. OBJECTIVE: To evaluate and summarize the clinical, laboratory, and histopathological characteristics of pernio-like lesions reported in the literature. METHODS: We conducted a search of the PubMed, SciELO, and ScienceDirect databases for articles published between January 1, 2020 and November 30, 2020, following the PRISMA recommendations (PROSPERO registration ID: CRD42020225055). The target population was individuals with suspected or laboratory-confirmed COVID-19 with pernio-like lesions. Observational studies, research letters, and case/series reports were all eligible for inclusion. Observational studies were evaluated using a random-effects model to calculate the weighted mean prevalence, overall mean, and 95% confidence interval. We evaluated case studies using the chi-square test for dichotomous variables and the Mann-Whitney test for continuous variables. RESULTS: A total of 187 patients from case reports and 715 patients from 18 observational studies were included. The mean age of patients was 16.6 years (range 14.5-18.8). Feet were affected in 91.4% (87.0-94.4%) of patients in observational studies. The proportion of patients with a positive RT-PCR test was less than 15%. Lesion topography and morphology were associated with age. CONCLUSION: Lesions mostly occurred in pediatric patients, and the morphological characteristics tended to differ between pediatric and non-pediatric populations. There is a possible multifactorial component in lesion pathophysiology. The non-positivity of laboratory tests does not exclude an association with COVID-19. Pernio-like lesions may be a late manifestation of COVID-19.