Epidemiologic Analysis of Chilblains Cohorts Before and During the COVID-19 Pandemic

Abstract

n early 2020, dermatologists in Europe noticed a sharp increase in chilblains, an inflammatory dermatosis that generally affects the dorsal feet or hands during periods of damp and cold, but not freezing, conditions, associated with the COVID-19 pandemic. [1][2][3][4][5][6][7][8] Few patients with chilblains tested positive for SARS-CoV-2 or its antibodies, although access to testing was limited. [1][2][3][4] Subsequent reports of series with complete viral and antibody testing indicated low frequencies of tests with positive results. [5][6][7][8] The underlying causes of an increase in chilblains related to the pandemic are controversial. 5,[7][8][9][10] Published cases of presumed secondary chilblains in the setting of confirmed COVID-19 infection indicate that COVID-19associated symptoms preceded chilblains by up to 30 days. 2,11 On noticing an increase in chilblains after the shelter-athome order was initiated in 6 Bay Area counties in California on March 16, 2020 (and statewide on March 18, 2020), we conducted a retrospective cohort study to test the hypothesis that increased cases of chilblains appeared in the same locations as increased cases of COVID-19 over time. Methods Setting and DesignKaiser Permanente Northern California provides comprehensive, integrated care to 4.4 million people, with all clinical information entered into an electronic medical record. The health care system operates 23 medical centers that are located to serve defined urban, suburban, and exurban population centers. Northern California is known for its microclimates. The IMPORTANCE Beginning in March 2020, case reports and case series linked the COVID-19 pandemic with an increased occurrence of chilblains, but this association has not been evaluated in an epidemiologic study.OBJECTIVE To assess whether a correlation exists between COVID-19 incidence and chilblains incidence. DESIGN, SETTING, AND PARTICIPANTSA retrospective cohort study was conducted within the Kaiser Permanente Northern California system from January 1, 2016, to December 31, 2020; health plan members of all ages were included.EXPOSURE COVID-19 incidence in 207 location-months, representing 23 geographic locations in northern California across 9 months. MAIN OUTCOME AND MEASURESChilblains incidence was the main outcome. The association of chilblains incidence with COVID-19 incidence across the 207 location-months was measured using the Spearman rank correlation coefficient. RESULTSOf 780 patients with chilblains reported during the pandemic, 464 were female (59.5%); mean (SD) age was 36.8 (21.8) years. COVID-19 incidence was correlated with chilblains incidence at 207 location-months (Spearman coefficient 0.18; P = .01). However, only 17 of 456 (3.7%) patients with chilblains tested during the pandemic were positive for SARS-CoV-2, and only 9 of 456 (2.0%) were positive for SARS-CoV-2 within 6 weeks of the chilblains diagnosis. Test results of 1 of 97 (1.0%) patients were positive for SARS-CoV-2 IgG antibodies. Latinx patients were disproportionately affected by C...

Lack of association between pandemic chilblains and SARS-CoV-2 infection

“…These data are complementary to our study in that they fail to show evidence of infection in an early presumed exposure period, whereas our study describes similar results in the convalescent state. Altogether, these studies better support an alternative explanation for an increase in the incidence of chilblains, possibly attributed to altered behavior during the pandemic (e.g., not wearing socks/shoes at home during quarantine) and/or increased awareness due to reports of covid toe in the media as has been proposed elsewhere ( 16 , 22 ). In support of this theory, multiple initial encounters in our cohort documented the patient’s concern for a covid toe in the history of present illness, confirming the increased awareness of this entity by patients at the time.…”

Multicenter analysis of neutrophil extracellular trap dysregulation in adult and pediatric COVID-19

“…While acute SARS-CoV-2 infection is less severe among children(Chen et al, 2021; Ejaz et al, 2020; Yang et al, 2020), Multi-system Inflammatory Syndrome in Children (MIS-C)(Nakra et al, 2020; Rowley, 2020), characterized by fever, systemic inflammation, and multi-organ dysfunction following COVID-19, may occur (Consiglio et al, 2020; Noval Rivas et al, 2021). Cutaneous manifestations, such as chilblain-like lesions (CLL) or “COVID toes”, affects primarily children and young adults and are characterized by edema, erythema, violaceous discoloration on the fingers and toes, and occasional vesiculation (Baeck and Herman, 2021; Frumholtz et al, 2021; McCleskey et al, 2021). The occurrence of CLL has rapidly increased during the COVID-19 pandemic and correlates with confirmed COVID-19 incidence(McCleskey et al, 2021).…”

“…Cutaneous manifestations, such as chilblain-like lesions (CLL) or “COVID toes”, affects primarily children and young adults and are characterized by edema, erythema, violaceous discoloration on the fingers and toes, and occasional vesiculation (Baeck and Herman, 2021; Frumholtz et al, 2021; McCleskey et al, 2021). The occurrence of CLL has rapidly increased during the COVID-19 pandemic and correlates with confirmed COVID-19 incidence(McCleskey et al, 2021). Biopsy of affected tissue may confirm the diagnosis, with superficial and deep dermal lymphocytic infiltrates surrounding eccrine glands and blood vessels(Andina et al, 2020; Hernandez and Bruckner, 2020; Kanitakis et al, 2020; Massey and Jones, 2020).…”

Quoi de neuf en dermatologie clinique ?

“…Le nombre de cas a très nettement augmenté en 2020 par rapport à 2016-2019 mais avec une faible corrélation géographique avec les zones les plus touchées par la COVID et une faible corrélation avec l’âge (forte incidence chez les 13-19 ans pour les engelures, chez les 20-59 ans pour la COVID). Enfin, avant la pandémie en 2016-2019, les 2 pics d’incidences des engelures étaient au printemps et à l’automne, comme pendant la pandémie, témoignant du caractère saisonnier bien connu des engelures [ 16 ]. Par conséquent, la récidive des engelures en automne ne semble pas un argument pour l’association avec la COVID.…”