Search

Livedo racemosa is a cutaneous finding characterized by a persistent, erythematous, or violaceous discoloration of the skin, in a broken, branched, discontinuous, and irregular pattern. A retrospective review of 33 cases with clinical diagnosis of livedo racemosa over the past 6 years was evaluated in the dermatology department of a tertiary care hospital. We found predominance in Caucasian women (78.8%); age ranged from 8 to 81 years, with a mean age of 36 years. Livedo racemosa was described as generalized in 12 patients (36.4%), although the main localization was on lower limbs (42%). After laboratory testing and histopathological examinations, 12 patients (36.4%) were classified with idiopathic livedo racemosa; secondary diseases were diagnosis in 21 patients (63.6%), including Sneddon's syndrome, cutaneous polyarteritis nodosa, systemic lupus erythematosus, and others. Medical history of thrombotic events was described in 8 (24.2%) patients, and also 8 (24.2%) patients had abnormal results for 2 or more thrombophilia laboratory tests. Skin biopsy showed no histological abnormalities in 11 cases (33.3%), thrombosis of dermal blood vessels in 10 (30.3%), intimal/subintimal thickening in 7 (21.2%), and vasculitis in 5 (15.2%). In conclusion, livedo racemosa is a clinical feature that might be correlated to vascular disorders, such as thrombotic and/or hypercoagulable states, autoimmune diseases, and neoplastic diseases, or it can be secondary to specific medications. It is essential to establish a correct approach in cases of livedo racemosa, which includes anamnesis, physical examination, laboratory test, histological examination, and complementary examination according to clinical findings, in order to diagnosis underlying causes. [ABSTRACT FROM AUTHOR]

Coronavirus disease (COVID‐19) pandemic presents several dermatological manifestations described in the present indexed literature, with around 700 cases reported until May 2020, some described as urticaria or urticarial rashes. Urticaria is constituted by evanescent erythematous‐edematous lesions (wheals and flare), which does not persist in the same site for more than 24 to 48 hours and appears in other topographic localization, resolving without residual hyper pigmentation. During the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, some cytokines are synthesized, including Interferon (IFN) type I, TNF‐α, and chemokines which may induce mast cells (MCs) and basophils degranulation by mechanisms similar to the autoinflammatory monogenic or polygenic diseases. In this article, we discuss the spectrum of the urticaria and urticarial‐like lesions in the COVID‐19's era, besides other aspects related to innate and adaptative immune response to viral infections, interactions between dermal dendritic cells and MCs, and degranulation of MCs by different stimuli. Plasmacytoid dendritic cells share, in allergic patients, expression of the high‐affinity IgE receptors on cell membranes and demonstrated a low pattern of type I IFN secretion in viral infections. We discuss the previous descriptions of the effects of omalizumab, a monoclonal antibody directed to IgE and high‐affinity IgE receptors, to improve the IFN responses and enhance their antiviral effects. [ABSTRACT FROM AUTHOR]