Negative tests for SARS-CoV-2 infection do not rule out its responsibility for chilblains

Case Report: Generalised Panniculitis as a Post-COVID-19 Presentation in Aicardi-Goutières Syndrome Treated With Ruxolitinib

Aicardi-Goutières syndrome (AGS) is a rare hereditary early-onset encephalopathy. The syndrome was first described in 1984, and is characterised by upregulation of the type I interferon (IFN) pathway, which is involved in the host immune response against viral infections, including SARS-CoV-2. Whilst defects in type I IFN pathways have been described in association with severe coronavirus disease 2019 (COVID-19), less is known about the outcomes of upregulation. We describe an unusual case of generalised panniculitis as a post-COVID-19 phenomenon in a child with AGS. Our patient was initially managed with systemic steroid therapy, but due to relapse of symptoms on weaning, an alternative therapy was sought. In this case, a novel use of ruxolitinib, a JAK inhibitor, has resulted in lasting remission without complications. We discuss the probable protective role of IFN upregulation following COVID-19 infection in AGS and possible immunological mechanisms driving the panniculitis and therapeutic response in our case.

RNAscope in situ hybridization and RT-PCR for detection of SARS-CoV-2 in chilblain-like lesions: A clinical, laboratory and histopathological study

BACKGROUND

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, an increasing number of chilblain-like lesions (ChLL) have been increasingly reported worldwide. To date, the causal link between ChLL and SARS-CoV-2 infection has not been unequivocally established.

METHODS

In this case series, we present demographic, clinical, laboratory, and histopathological information regarding 27 young patients with a clinical diagnosis of ChLL who referred to the Dermatology Unit of Papa Giovanni XXIII Hospital, Bergamo, Italy, from 1 April 2020 to 1 June 2020.

RESULTS

The mean age was 14.2 years, and 21 patients (78%) experienced mild systemic symptoms a median of 28 days before the onset of cutaneous lesions. ChLL mostly involved the feet (20 patients - 74%). Among acral lesions, we identified three different clinical patterns: (i) chilblains in 20 patients (74%); (ii) fixed erythematous macules in 4 children (15%); (iii) erythrocyanosis in 3 female patients (11%). Blood examinations and viral serologies, including parvovirus B19, cytomegalovirus (CMV), Epstein-Barr virus (EBV), and coxsackievirus were normal in all. Three patients (11%) underwent nasopharyngeal swab for RT-PCR for SARS-CoV-2 showing only 1 positive. Histopathological examinations of 7 skin biopsies confirmed the clinical diagnosis of chilblains; vessel thrombi were observed only in 1 case. Our findings failed to demonstrate the direct presence of SARS-CoV-2 RNA in skin biopsies, both with real-time polymerase chain reaction (RT-PCR) and RNAscope in situ hybridization (ISH).

LIMITATIONS

Limited number of cases, unavailability of laboratory confirmation of COVID-19 in all patients, potential methodological weakness, and latency of skin biopsies in comparison to cutaneous lesions onset.

CONCLUSIONS

These observations may support the hypothesis of an inflammatory pathogenesis rather than the presence of peripheral viral particles. Although, we could not exclude an early phase of viral endothelial damage followed by an IFN-I or complement-mediated inflammatory phase. Further observations on a large number of patients are needed to confirm this hypothesis.

Six months into the pandemic. A review of skin manifestations in SARS-CoV-2 infection

During the COVID‐19 pandemic, various cutaneous manifestations have been described as associated with SARS‐CoV2 infection. It is debated if skin lesions could represent a diagnostic or prognostic indicator. Specifically, it is unclear whether skin lesions may be used to perform an early diagnosis and/or to predict worse outcomes. In this review, we described the cutaneous signs so far reported as COVID‐19‐related and discussed their incidence, clinico‐pathological features, and diagnostic and prognostic value.

Impaired type I interferon response in SARS-CoV-2 infection: looking through the cutaneous window

Linked Article: Magro et al. Br J Dermatol 2021; 184:141–150.