BackgroundChronic urticaria (CU) is a chronic inflammatory skin disease associated with Th2 immune response. The two most common subtypes of CU, i.e., chronic spontaneous urticaria and symptomatic dermographism (CSD), often coexist. However, the pathogenesis of CSD is still unclear. Gut microbiota plays an important role in immune-related inflammatory diseases. The purpose of this study was to explore the correlation between gut microbiota and CSD.MethodsA case-control study was conducted on CSD patients as well as gender- and age-matched normal controls (NCs). The 16S ribosomal DNA sequencing of fecal samples was used to detect the gut microbiota of all subjects. QPCR was used to further verify the species with differences between the two groups.ResultsThe alpha diversity of gut microbiota decreased in CSD patients, accompanied by significant changes of the structure of gut microbiota. Subdoligranulum and Ruminococcus bromii decreased significantly in CSD patients and had a potential diagnostic value for CSD according to receiver operating characteristic curve (ROC) analysis. Enterobacteriaceae and Klebsiella were found to be positively correlated with the duration of CSD, while Clostridium disporicum was positively correlated with the dermatology life quality index (DLQI).ConclusionsThe gut microbiota of CSD patients is imbalanced. Subdoligranulum and Ruminococcus bromii are the gut microbiota biomarkers in CSD.

Chronic urticaria (CU) is a mast cell-driven skin disease, with an average lifetime prevalence of 1.4%. 1 Chronic spontaneous urticaria (CSU) is a common clinical subtype of chronic urticaria. It has been reported that the impact of CSU on the quality of life of patients is comparable to that of coronary artery disease, 2 which causes a great economic and social burden. 3,4 Although its pathogenesis has not been fully clarified, advances had been made over the past years, such as identification of mast cell surface-related receptors

No abstract

Background: The subtypes of chronic urticaria share a common clinical expression, but may show differences phenotypically. Meanwhile, two or more different subtypes of chronic urticaria can coexist in any given patient which may involve different phenotypes. Aims: The study aims to compare the two phenotypes in terms of demographics, clinical profile and treatment response. Methods: In this retrospective study, 2678 chronic urticaria patients were divided into the single subtype chronic urticaria group and mixed subtype chronic urticaria group as was appropriate.The differences in the clinical features, possible causes, urticaria activity score of seven days, dermatology life quality index score, laboratory investigations and response to treatments were evaluated among the two groups. Results: An obvious female predominance was detected in chronic urticaria, especially in mixed subtype chronic urticaria patients. Of the 2678 chronic urticaria patients, there were 837(31.25%) mixed subtype chronic urticaria. Chronic spontaneous urticaria combined with symptomatic dermographism was the most common group in the mixed subtype chronic urticaria. Patients with mixed subtype chronic urticaria were more likely to have associated chest tightness/shortness of breath and showed greater urticaria activity. In patients with single subtype chronic urticaria, the positive rate of family history with allergic rhinitis, asthma or urticaria was lower. Based on evaluation of the treatment, control with second-generation antihistamines at licensed doses was achieved in only 38.83% of mixed subtype chronic urticaria patients, compared with 56.32% of patients with single subtype. Limitations: First, this study was a single-center design retrospective study. Second, omalizumab treatment was not included. Third, the differences between different subtypes of mixed subtype chronic urticaria were not discussed in detail. Conclusion: This study showed that mixed subtype chronic urticaria had some distinct features. Comprehensive knowledge about it may help us define effective therapeutic strategies and improve symptom control and the quality of life for chronic urticaria patients.

Symptomatic dermographism (SD), the most common type of physical urticaria, refers to the urticaria response to different kinds of physical stimulation, with a prevalence of 2-5%. 1,2 It is characterized by strip-shaped wheals at the scratching and friction sites, accompanied by local itching or burning sensation. 1,3 The average duration of SD is ranged from 5 to 7 years. It can seriously affect the quality of life of patients, leading to problems such as sleep disorder, chronic fatigue and even inability to live a normal life. 3,4 Although the exact pathogenesis is still unknown, allergic inflammation and immune imbalance may act a pivotal part in SD. 5,6 Gut microbiota plays a crucial role in maintaining the immune homeostasis of the host. 7 In recent years, gut microbiota has also