Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2024;14(4):e2024252 1 Omalizumab In The Treatment Of Refractory Urticarial Vasculitis Triggered By SARS-Cov-2 Infection: A Pediatric Case Report Yusuf Can Edek1, Ecem Ertürk1, Esra Adışen1 1 Department of Dermatology, Gazi University Faculty of Medicine, Ankara, Turkey Key words: COVID-19, Omalizumab, Urticarial vasculitis Citation: Edek YC, Ertürk E, Adışen E. Omalizumab in the treatment of refractory urticarial vasculitis triggered by SARS-CoV-2 infection: A pediatric case report. Dermatol Pract Concept. 2024;14(4):e2024252. DOI: https://doi.org/10.5826/dpc.1404a252 Accepted: May 15, 2024; Published: October 2024 Copyright: ©2024 Edek et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Yusuf Can Edek, Gazi Universitesi Tip Fakultesi Hastanesi, Emniyet Mahallesi, Mevlana Bulvari, No:29, 06560 Ankara, Turkey. Phone: +903122026129/+905062818274. E-mail: yusuf-can-35@hotmail.com Introduction Urticarial vasculitis is a small-vessel vasculitis type that can be difficult to distinguish from chronic idiopathic urti- caria. Lesions that persist longer than 24 hours, along with the associated burning sensation and hyperpigmentation, can aid  in identifying urticarial vasculitis. While elevated sedimentation rate and hypocomplementemia are common laboratory abnormalities in urticarial vasculitis, histopatho- logical analysis may show features of leukocytoclastic vas- culitis. Treatment options for urticarial vasculitis include antihistamines, systemic steroids, colchicine, cyclosporine, methotrexate, and omalizumab [1,2]. Herein, we present a pediatric urticarial vasculitis case secondary to SARS-CoV-2 infection, treated with omalizumab. Case Presentation A 6-year-old healthy boy presented to our clinic due to itchy rashes. His parents described that the lesions began on the leg 10 days after the SARS-CoV-2 infection diagno- sis six months earlier and that the lesions had spread over time. Dermatological examination showed annular urticar- ial plaques, purpuras, and hyperpigmented patches on the trunk, extremities, and face (Figure 1). Histopathological analysis of the punch biopsy of the urticarial plaque on the trunk showed perivascular dermal infiltration, endothelial swelling, and leukocytoclasia. While laboratory evaluation revealed a high immunoglobulin level (1030 kU/L), the com- plement levels were evaluated as normal. The patient was diagnosed with normocomplementemic urticarial vasculitis based on clinical examination and histopathological find- ings. Considering the time of development of the complaints and the absence of any other triggering factors, it was con- cluded that the urticarial vasculitis developed secondary to the SARS-CoV-2 infection. Following oral prednisolone (1 mg/kg) and desloratadine treatment, complete treatment response was detected, and steroid treatment was tapered. When the patient’s complaints recurred while the steroid dose was reduced, omalizumab treatment was chosen since 2 Research Letter | Dermatol Pract Concept. 2024;14(4):e2024252 literature data indicates that it is beneficial for treating ur- ticarial vasculitis and is a safe medication in terms of side effects. Omalizumab treatment was administered subcutane- ously for 150 mg/4 weeks, and at the 1-year follow-up, the patient’s symptoms had regressed without any recurrence or side effects. Discussion While the etiology of urticarial vasculitis may be idiopathic, malignancies, connective tissue diseases, and infections also can be a triggering factor. In the literature, several skin con- ditions linked to SARS-CoV-2 have been described, with urticarial vasculitis being one of them. The exact pathogen- esis of SARS-CoV-2-induced urticarial vasculitis remains unknown; however, virus-mediated endothelial cell dam- age and immune system dysregulation, as immune complex deposition and complement-induced cytotoxicity play a role in the pathogenesis [1,3]. Treatment of urticarial vasculitis in pediatric cases is challenging due to the unsatisfactory effectiveness of anti- histamines and the restrictive use of long-term systemic ste- roids or immunosuppressive agents due to side effects [4]. Omalizumab is a humanized monoclonal antibody targeting IgE used in chronic spontaneous urticaria treatment. Recent studies have shown that omalizumab is effective in treating urticarial vasculitis [5]. Wang et al. reported that four pedi- atric urticarial vasculitis patients unresponsive to systemic steroid treatment were successfully treated with omalizumab without any side effects or recurrence [4]. Conclusion We would like to highlight with this case report that urticar- ial vasculitis may be one of the skin conditions linked with SARS-CoV-2 and that omalizumab may be a safe treatment agent in pediatric urticarial vasculitis cases. References 1. Marzano AV, Maronese CA, Genovese G, et al. Urticarial vas- culitis: Clinical and laboratory findings with a particular em- phasis on differential diagnosis. J Allergy Clin Immunol. 2022; 149(4):1137-1149. DOI:10.1016/j.jaci.2022.02.007 2. Kolkhir P, Grakhova M, Bonnekoh H, Krause K, Maurer M. Treatment of urticarial vasculitis: A systematic review. J Allergy Clin Immunol. 2019;143(2):458-466. DOI:10.1016/j.jaci.2018 .09.007 3. de Perosanz-Lobo D, Fernandez-Nieto D, Burgos-Blasco P, et al. Urticarial vasculitis in COVID-19 infection: a vasculopathy- related symptom? J Eur Acad Dermatol Venereol. 2020;34(10): e566-e568. DOI:10.1111/jdv.16713 4. Wang S, Fu L, Xiang X, Zhang B, Ma L, Xing H. Successful treat- ment of urticarial vasculitis with omalizumab in children: a case series. Clin Exp Dermatol. 2023;48(10):1145-1148. DOI:10.1093 /ced/llad192 5. Petrelli F, Giannini D, Bilia S, et al. Efficacy and safety of omalizumab therapy in urticaria vasculitis.  Front Allergy. 2022;3:952079. DOI:10.3389/falgy.2022.952079 Figure 1. Widespread annular erythematous urticarial plaques and hyperpigmentation on the (A) trunk, (B) face, and (C) leg.