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.

Cutaneous manifestations in a series of 417 patients with SARS-CoV-2 infection: epidemiological and clinical correlates of chilblain like lesions

A variety of dermatological lesions have been described in COVID-19, although the prevalence and pathogenic relationship remain unclear particularly for chilblain-like lesions. Dermatological examination was performed in a prospective cohort of consecutive patients seen at the service for SARS-CoV-2 infection. Out of 417 patients with confirmed SARS-CoV-2 infection [median age 29.5 years (range 15-65); 62.5% males], dermatological lesions were detected in 7 (1.7%). Three patients had acral lesions; their age (range) was 15-29 years; all had a negative nasopharyngeal swab and developed IgG and/or IgM-specific antibodies; all presented none or mild symptoms. A fourth patient remained negative at repeated testing; mother, father and sister had a documented mild COVID-19. Non-acral lesions were observed in four older patients, with severe COVID-19. Chilblain-like lesions may be the sole manifestation of SARS-CoV-2 infection; their presence in asymptomatic school children and adolescents should be considered a potential signal of familial or community spread of the virus.

Syphilis Resurrected: Case Series of Palmoplantar Secondary Syphilis

Introduction Syphilis is a sexually transmitted infection caused by Treponema pallidum which has protean manifestations. The cutaneous presentation of syphilis can mimic many dermatologic conditions.  Materials & methods With an aim to describe palmoplantar involvement in syphilis, a retrospective study of case series was done with 11 patients having palmoplantar skin lesions in syphilis within a period of two years. Only serologically confirmed cases were included. Results The prevalence of palmoplantar involvement in syphilis was 47.85% and all of them except one patient (congenital syphilis) were secondary syphilis. A major proportion of cases (72.8%) studied had no history or presentation of genital lesions. Biett's collar which is an indicator of palmoplantar syphilis was seen only in 45.5% of the cases. Conclusion The clinicians must be aware that palmoplantar skin lesions might be the only clinical presentation of syphilis and a high index of suspicion is needed to correctly diagnose and treat the condition in such a setting.

COVID-associated non-vasculitic thrombotic retiform purpura of the face and extremities: A case report

SARS-CoV-2 infection can manifest many rashes. However, thrombotic retiform purpura rarely occurs during COVID-19 illness. Aggressive anti-COVID-19 therapy with a high-dose steroid regimen led to rapid recovery. This immunothrombotic phenomenon likely represents a poor type 1 interferon response and complement activation on the endothelial surface in response to acute infection.