Snotwatch COVID-toes: An ecological study of chilblains and COVID-19 diagnoses in Victoria, Australia

  1. Rana Sawires
  2. Christopher Pearce
  3. Michael Fahey
  4. Hazel Clothier
  5. Karina Gardner
  6. Jim Buttery

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Abstract

The COVID-19 pandemic has caused widespread illness with varying clinical manifestations. One less-commonly-reported presentation of COVID-19 infection is chilblain-like lesions. We conducted an ecological analysis of chilblain presentations in comparison with confirmed and suspected COVID-19 infections in a primary care setting to establish that a relationship exists between the two. Our study collated data from three Primary Health Networks across Victoria, Australia, from 2017–2021, to understand patterns of chilblain presentations prior to and throughout the pandemic. Using a zero-inflated negative binomial regression analysis, we estimated the relationship between local minimum temperature, COVID-19 infections and the frequency of chilblain presentations. We found a 5.72 risk ratio of chilblain incidence in relation to COVID-19 infections and a 3.23 risk ratio associated with suspected COVID-19 infections. COVID-19 infections were also more strongly associated with chilblain presentations in 0-16-year-olds throughout the pandemic in Victoria. Our study statistically suggests that chilblains are significantly associated with COVID-19 infections in a primary care setting. This has major implications for clinicians aiming to diagnose COVID-19 infections or determine the cause of a presentation of chilblains. Additionally, we demonstrate the utility of large-scale primary care data in identifying an uncommon manifestation of COVID-19 infections, which will be significantly beneficial to treating physicians.

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  1. Version published to 10.1371/journal.pgph.0000488
  2. ScreenIT

    SciScore for 10.1101/2022.04.21.22274140: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: Ethics approval: Ethical approval for Snotwatch projects was obtained through our primary Human Research Ethics Committee (HREC) in Monash Health from 24th July 2019 (NMA/ERM Reference Number: 53611).
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Statistical Analysis: The coding program, R (version 4.0.2),12 was applied through RStudio (version 1.2.5)13 for statistical analysis of temporal data.
    RStudio
    suggested: (RStudio, RRID:SCR_000432)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Nevertheless, there are some key limitations to our dataset. Over the course of the pandemic, most COVID-19 diagnoses in Victoria were not made in a GP setting. As such, our chilblains diagnosis data are only a subset of all COVID-19 infections that occurred in the last two years. There is also uncertainty around how general practitioners coded COVID-19 diagnoses and whether there was a time delay between a patient having a confirmed COVID-19 infection and their general practice visit at which this diagnosis would have been recorded. We included suspected COVID-19 diagnosis in our analysis for completion, but this is an unreliable measure of COVID-19 infection in the state and may not accurately represent circulation of COVID-19 infections in Victoria. An additional factor to consider is that a significant proportion of cases in Victoria were diagnosed through state-run testing hubs with minimal notification back to GPs. This may have skewed our results and masked possible lead and lag associations between chilblains and COVID-19. Ultimately, the ecological analysis conducted in this study means that we can only demonstrate associations between our datasets, and a causal relationship between COVID-19 infection and chilblains presentations cannot be confirmed. Nevertheless, our findings lay the foundation for future research which may confirm a causal relationship, as well as ascertain the pathophysiology and aetiology of chilblains due to COVID-19 infection.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

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  3. Version published to 10.1101/2022.04.21.22274140 on medRxiv