Background: Information/communication technologies such as mobile phone applications (apps) would enable chronic urticaria (CU) patients to self-evaluate their disease activity and control. Yet, recently Antó et al (2021) reported a global paucity of such apps for patients with CU. In this analysis, we assessed patient interest in using apps to monitor CU disease activity and control using questions from the CURICT study, Methods: The methodology for CURICT has been reported. Briefly, a 23-item questionnaire was completed by 1,841 CU patients from 17 UCAREs across 17 countries. Here, we analyzed patient responses to the CURICT questions on the use of apps for urticaria-related purposes. Results: As previously published, the majority of respondents had chronic spontaneous urticaria (CSU; 63%; 18% chronic inducible urticaria [CIndu]; 19% with both), were female (70%) and in urban areas (75%). Over half of patients were very/extremely interested in an app to monitor disease activity (51%) and control (53%), while only ~1/10 were not. Patients with both urticaria types vs those with CSU only (OR, 1.36 [1.03-1.79]) and females vs males (OR[95%CI], 1.47 [1.17-1.85]) were more likely to be very to extremely interested in an app to assess disease control. Conclusions: Overall, patients with CU were highly interested in using an app to assess their disease activity and control. Development of well-designed apps, specific to disease types (CSU, CIndU, CSU+CIndU, etc), validated by experts across platforms would help improve the management and possibly outcomes of CU treatment while providing important patient information to be used in future research.

Systemic allergic reactions to vaccines are very rare. In this study we assessed the management and outcome suspected SARS-CoV-2 vaccine hypersensitivity. We present data of 219 individuals, who experienced symptoms suspicious for an allergic reaction after the first (n=214) or the second vaccination (n=5). 195 reactions occurred after the first application of mRNA-based vaccines (157 Comirnaty®, and 38 Spikevax®) and eighteen reactions were reported after first application of a vector vaccine (Vaxzevria®). Of these 162 experienced immediate symptoms. Skin symptoms occurred in 91 cases. The most frequent cutaneous symptom was angioedema (n=45), followed by generalized urticaria (n=36) and generalized erythema/flush (n=20). 70 patients had cardiovascular symptoms, 45 showed respiratory symptoms and gastrointestinal symptoms were recorded in 14 patients. The allergological assessment of 334 individuals (219 with reactions after COVID vaccination and 115 with a history of vaccine related reactions) showed in 17% a suspicion of sensitization against the SARS-CoV-2 vaccine and/or their ingredients defined as one positive skin test and/or BAT. The majority of the SPT/IDT with the vaccines were negative. Of the 214 patients with suspected allergic symptoms after the first vaccination, 67/67 patients tolerated the re-vaccination. In this study, 334 individuals of a cohort resembling >2000 persons presenting for an allergy workup regarding SARS-CoV-2 vaccination only 45 were diagnosed in concordance with the anaphylaxis definition of the Brighton collaboration with anaphylactic immediate hypersensitivity reaction after SARS-CoV-2 vaccination. Identifiable characteristics of these patients with suspected, but also diagnosed SARS-CoV-2 vaccine hypersensitivity were female gender and the symptom angioedema. Overall, IgE-mediated hypersensitivity towards SARS-CoV-2 vaccines is extremely low and not increased in comparison to the reported hypersensitivity for other vaccines.

Low and high IgE is linked to improvement and worsening of chronic urticaria during pregnancy, respectively Kocatürk E, Thomsen SF, Al-Ahmad M, Gimenez-Arnau A, Conlon N, Savk E, Criado RF, Danilycheva I, Fomina D, Khoshkhui M, Gelincik A, Degirmentepe EN, Demir S, Ensina LF, Kasperska-Zajac A, Rudenko M, Bauer A, Medina I, Maurer M.1 Urticaria Center of Reference and Excellence (UCARE), Dept. of Dermatology, Koç University School of Medicine, Istanbul, Turkey ekocaturk@ku.edu.tr2 Urticaria Center of Reference and Excellence (UCARE), Center of Reference and Excellence (UCARE), Department of Dermatology, Bispebjerg Hospital, Copenhagen, Denmark simonfrancisthomsen@gmail.com3 Urticaria Center of Reference and Excellence (UCARE), Microbiology Department, Faculty of Medicine, Kuwait University, Safat, Kuwait monaalahmad@yahoo.com4 Urticaria Center of Reference and Excellence (UCARE), Department of Dermatology, Hospital del Mar, IMIM, Universitat Autònoma, Barcelona, Spain anamariagimenezarnau@gmail.com5 Urticaria Center of Reference and Excellence (UCARE), Dermatology, and Immunology, St James’s Hospital, Dublin, Ireland conlonn1@tcd.ie6 Aydın Adnan Menderes University, Aydın, Turkey esavk@adu.edu.tr7 Urticaria Center of Reference and Excellence (UCARE), Faculdade de Medicina do ABC (FMABC), Santo André, Brazil roberta.criado@fmabc.br8 Urticaria Center of Reference and Excellence (UCARE), NRC Institute of Immunology FMBA of Russia, Moscow, Russia ivdanilycheva@mail.ru9 Urticaria Center of Reference and Excellence (UCARE), First Moscow State Medical University, Moscow Center of Allergy and Immunology , Clinical Hospital 52 , Ministry of Moscow Healthcare, Moscow, Russia daria.s.fomina@gmail.com10 Urticaria Center of Reference and Excellence (UCARE), Allergy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Khoshkhuim@mums.ac.ir11 Urticaria Center of Reference and Excellence (UCARE), Istanbul Faculty of Medicine Istanbul University, Istanbul, Turkey gelincikasli@hotmail.com12 Urticaria Center of Reference and Excellence (UCARE), Okmeydani Training and Research Hospital, Istanbul, Turkey ecenuryksel@gmail.com13 Urticaria Center of Reference and Excellence (UCARE), Istanbul Faculty of Medicine Istanbul University, Istanbul, Turkey ERTANSEMRA@yahoo.com14 Urticaria Center of Reference and Excellence (UCARE), Federal University of São Paulo, Sao Paulo, Brazil 100alergia@gmail.com15 Urticaria Center of Reference and Excellence (UCARE), European Center for Diagnosis and Treatment of Urticaria (GA2LEN UCARE Network) Medical University of Silesia in Katowice, Poland alakasperska@gmail.com16 Urticaria Center of Reference and Excellence (UCARE), The London Allergy & Immunology Centre, London, United Kingdom consultation@ukallergy.com17 Urticaria Center of Reference and Excellence (UCARE), Department of Dermatology, University Allergy Center, University Hospital Carl Gustav Carus, Technical University Dresden, Germany. Andrea.Bauer@uniklinikum-dresden.de18 Urticaria Center of Reference and Excellence (UCARE), the Centro Médico Vitae, Buenos Aires, Argentina irisvmedina@gmail.com19 Urticaria Center of Reference and Excellence (UCARE), Dermatological Allergology, Allergie-Centrum-Charité, Dept. of Dermatology and Allergy, Charité – Universitätsmedizin Berlin, Germany marcus.maurer@charite.deDear Editor,PREG-CU, the recent study on pregnancy and chronic urticaria (CU) by the Urticaria Centers of Reference and Excellence (UCAREs), showed that CU improves in half (51.1%) of patients during pregnancy, whereas 28.9% and 20% of patients, respectively, experienced worsening and no change. Low disease activity, no angioedema, and no treatment before pregnancy were risk factors for worsening during pregnancy (1).We hypothesized that patients with chronic spontaneous urticaria (CSU) that worsens during pregnancy are more likely to have type I autoimmune CSU, also called autoallergic CSU. We also hypothesized that patients who improve during pregnancy are more likely to have type IIb autoimmune CSU (2). This hypothesis is supported by the immunological changes observed during pregnancy, i.e., decreased Th1 and Th17 immunity and a switch to a Th2-type cytokine profile (3).To test this hypothesis, we retrieved total IgE levels of CSU patients who gave consent to be included in the PREG-CU study (1). Elevated IgE levels have been reported to be linked to autoallergic CSU, whereas low IgE is a marker of type IIb autoimmune CSU (4).Total IgE blood levels were available for 115 of the 218 CSU patients not treated with omalizumab enrolled in PREG-CU. The median IgE level was 106 (range: 3-1664 IU/mL), more than half of patients (51.3%) had elevated IgE (≥100 IU/mL), and 17.4% had low IgE (<40 IU/mL). Most patients with mild disease (51%) or moderate disease (61%), but only one in four patients with severe disease (26%) had elevated IgE levels (≥100 IU/mL). IgE levels were lower in patients with severe disease (68 IU/mL) vs mild (112 IU/mL; p=0.009) or moderate disease (128 IU/mL; p=0.018), and low IgE levels (<40 IU/mL) were more frequent in patients with severe than mild disease (36.8 vs 11.6%; p=0.034).CSU patients who got worse during pregnancy had higher IgE levels (154 vs. 82.2 IU/mL; p=0.033) and numerically higher rates of elevated IgE (57.5 vs. 46%) compared to patients who got better during pregnancy. In contrast, patients who improved during pregnancy more often had low IgE levels than patients who deteriorated (22 vs. 12.5%), but this was not statistically significant. One in three of our patients (34.9%) had elevated anti-TPO, another marker of type IIb autoimmune CSU, but this was not linked to improvement during pregnancy.Worsening of CSU during pregnancy in patients with high IgE levels may be explained, in part, by the role that IgE and Th2 immunity play in the pathogenesis of their CSU. High IgE, in CSU, has been linked, in some studies, to autoallergy, characterized by the presence of IgE autoantibodies (5). Pregnancy skews immunity towards Th2 responses and patients with Th2-driven diseases, including allergies, often experience worsening of their disease during pregnancy (3). Improvement of CSU during pregnancy in patients with low IgE may point to a role of Th1 and Th17 cytokines in the pathogenesis of their disease. Low IgE is a type IIb autoimmune CSU marker, which is linked to Th1 and Th17 autoimmunity (6). Pregnancy decreases Th1/Th17 immunity, and patients with TH1/TH17-driven autoimmune diseases often experience improvement during pregnancy (3). Our finding that elevated IgG-anti-TPO, another marker of type IIb autoimmune CSU, is not linked to CSU improvement during pregnancy remains unexplained. Many CSU patients with IgG-anti-TPO also have IgE-anti-TPO and vice versa, which could point to both autoallergic and autoimmune drivers of their CSU. Better biomarkers are needed to identify which patients have autoallergic CSU, autoimmune CSU, both or none of these.Our findings support the notion that CSU is a heterogeneous disease, with at least two endotypes, i.e., autoallergic and autoimmune. Further studies are needed to better characterize the course of disease during and after pregnancy, in patients with autoallergic CSU and with autoimmune CSU. IgE levels may help to predict which CSU patients get worse and which improve when they get pregnant.