Altered Gut Microbiota in H1-Antihistamine-Resistant Chronic Spontaneous Urticaria Associates With Systemic Inflammation.

Background and Objective: Chronic spontaneous urticaria (CSU) is a histamine-mediated inflammatory skin disease, and second-generation non-sedating H1-antihistamines (nsAH) at licensed doses have long been the first-line therapy in CSU. However, about 50% of patients are resistant to nsAH, and the precise pathogenesis remains largely unknown but seems to be associated with low-level systemic or intestinal inflammation. We aim to determine the fecal microbial composition and clarify its correlation with the clinical profiles og CSU with nsAH resistance. Methods: A total of 25 CSU patients with or 19 CSU patients without nsAH resistance and 19 healthy controls (HC) were enrolled in this study. The intestinal microbiome was detected by 16S rRNA sequencing. The data were analyzed using R language software. Results: Significantly higher urticarial activity score for 7 days, stool calprotectin, erythrocyte sedimentation rate, serum C-reactive protein, and interleukin-6, but much lower alpha-diversity and evenness of fecal bacterial community were observed in CSU patients with nsAH resistance than in those without (P <0.05 for all variables). Compared to patients with nsAH-responsiveness, the abundance of fecal genera Prevotella, Megamonas, and Escherichia were significantly increased, while that of Blautia, Alistipes, Anaerostipes, and Lachnospira were remarkably reduced in nsAH-resistant patients (uncorrected P <0.05 for all variables). Finally, systemic not intestinal inflammation degree was positively correlated with genera Escherichia, while negatively with genera Blautia, Dorea, Lactobacillus, Eubacterium_hallii_group, and Roseburia. CSU without nsAH resistance and HC individuals showed almost unchanged genera bacterium. Conclusions: Among CSU patients, pro-inflammation phenotype relating to enteric dysbacteriosis features nsAH resistance in CSU patients. The results provide clues for future microbial-based or anti-inflammatory therapies on nsAH resistant CSU.

Contact sensitization to cosmetic series of allergens in female patients with rosacea: A prospective controlled study in China.

BACKGROUND: Allergic contact dermatitis to cosmetics (ACDC) complicates the diagnosis and treatment of rosacea, and is increasingly observed in daily practice. AIMS: The present study aimed to identify the contact allergens responsible for ACDC in Chinese female rosacea patients with or without suspected ACDC (SACDC). METHODS: From a total of 1267 women with rosacea, 122 with SACDC, 145 without SACDC, and 100 age-matched healthy controls without rosacea or SACDC were examined on a voluntary basis. Skin patch tests with C-1000 cosmetic series (Chemotechnique Diagnostics, Malmo, Sweden) were conducted, including 20 selected allergens. RESULTS: Positive allergic reaction was found in 85.2% and 33.8% of SACDC and non-SACDC (P < .001), respectively, and 27.0% of healthy volunteers. Most reactions occurred at day 3, and the majority of all the examinees including normal controls reacted to more than 1 allergen. In SACDC patients, leading allergens were methylchloroisothiazolinone/methylisothiazolinone (28.7%), linalool hydroperoxide (27.1%), fragrance mix I (21.3%), methylisothiazolinone (17.2%), limonene hydroperoxides (16.4%), formaldehyde (14.8%), myroxylon pereirae (13.9%), and propolis (10.7%); the overall allergic reaction rate positively correlated with new onset of facial pruritus (P < .001). The occurrence of irritant contact reactions correlated with positive allergic reactions in rosacea patients with or without SACDC (P = .032 or P < .001, respectively). CONCLUSIONS: Preservatives and fragrances are primary culprits for ACDC in Chinese female rosacea patients. Patch testing should be considered in the suspected patients.