Livedo reticularis as a late sign of COVID-19 temporally related multisystem inflammatory syndrome (MIS-C): A case series

ABSTRACT

Introduction: In children, the dermatologic features appear to occur early with other COVID-19 manifestations. Dermatologists play a key role in the early diagnosis of COVID-19. Multi-system inflammatory syndrome in children (MIS-C) shows a presentation mimicking Kawasaki Disease (KD), with mucocutaneous signs. However, late onset dermatological signs are poorly described. Objectives: to evaluate children with MIS-C during the follow-up and to describe late dermatological signs in these patients. Methods: We followed 14 children (3M;11 F) with MIS-C, with clinical, biochemical, imaging data. Autoantibodies, D-Dimer, CRP, ESR, C3, C4, ferritin, serum amyloid, IgA, IgM, IgG were detected 1-2 months after the resolution of the clinical manifestations of MIS-C. Results: 8/14 children (58%) showed livedo reticularis at the legs, arms, trunk. The livedo was more evident at the legs in all the patients. The livedo started at the remission, after normalization of CRP, ESR, D-Dimer;the sign lasted also for 1-2 months after the discontinuation of steroids and the normalization of haematochemical parameters. 4/8 showed low-title positive autoimmune tests (ANA in 2;ENA anti-Sm in 2;anti-cardiolipin IgG in 1;ASCA in 2). Conclusion: In our series, 8/14 patients showed a livedo reticularis, more marked in the legs, however in some cases with a wide distribution to arms and the trunk. Low-title autoantibodies were transiently positive in 50% of these cases, negative in later detections. Livedo reticularis was a late sign, linked to MIS-C related vasculitis, persisting 1-2 months after the resolution of MIS-C. A different treatment regimen (IVIG plus steroids at 1-2 or 30 mg/Kg/day) did not influence the progress of this clinical manifestation. In 50% of children we documented a transient autoimmune response.