摘要Introduction::Coronavirus disease 2019 (COVID-19) may be associated with various skin manifestations. Among them, figurate erythema (FE) is rare; only a few clinical reports have been published.Case presentation::A 52-year-old woman was diagnosed with COVID-19. One month later, she developed asymptomatic annular erythematous concentric ring lesions on her inner right thigh. The margin of every ring increased in coloration, and the lesions then completely resolved in 2 weeks. A biopsy revealed vasculitis of small vessels, an increase in the fluorescence intensity of CD3 and CD45, and negativity for COVID-19 RNA.Discussion::The results showed an unusual FE that has a clinical mixed type between erythema annulare centrifugum and erythema gyratum repens; the physiopathological mechanism in the FE due to COVID-19 is unknown; one theory involves rapid viral passage into the cutaneous vascular system that triggers an immune and inflammatory response. Although the results exhibited a negative COVID-19 RNA in the tissue, the CD3 +/CD45 + lymphocyte infiltration could explain the clinical pattern as a direct inflammatory response in the small vessel or as a delayed immune response. Conclusion::Our findings suggest an immunohistochemical small vessel vasculitis pattern with an unusual clinical FE that differs from other types of COVID-19–associated FE or erythema reported previously.

abstractsIntroduction::Coronavirus disease 2019 (COVID-19) may be associated with various skin manifestations. Among them, figurate erythema (FE) is rare; only a few clinical reports have been published.Case presentation::A 52-year-old woman was diagnosed with COVID-19. One month later, she developed asymptomatic annular erythematous concentric ring lesions on her inner right thigh. The margin of every ring increased in coloration, and the lesions then completely resolved in 2 weeks. A biopsy revealed vasculitis of small vessels, an increase in the fluorescence intensity of CD3 and CD45, and negativity for COVID-19 RNA.Discussion::The results showed an unusual FE that has a clinical mixed type between erythema annulare centrifugum and erythema gyratum repens; the physiopathological mechanism in the FE due to COVID-19 is unknown; one theory involves rapid viral passage into the cutaneous vascular system that triggers an immune and inflammatory response. Although the results exhibited a negative COVID-19 RNA in the tissue, the CD3 +/CD45 + lymphocyte infiltration could explain the clinical pattern as a direct inflammatory response in the small vessel or as a delayed immune response. Conclusion::Our findings suggest an immunohistochemical small vessel vasculitis pattern with an unusual clinical FE that differs from other types of COVID-19–associated FE or erythema reported previously.