Background: The aim of this study was to document the clinical features of children with mosquito allergy and investigate the possible associations between demographic features and type of reactions in this population. Methods: Children with large local or unusual reactions after mosquito bites who attended to our outpatient pediatric allergy department were enrolled in the study along with control subjects. Results: A total of 180 children (94 with mosquito allergy and 86 age and sex-matched control subjects) with a median age of 6.8 years (IQR 5.5-9.3) were enrolled. Atopy (35.1% vs. 11.6%, p<0.001) and grass pollen sensitization (28.7% vs. 8.1%, p<0.001) were significantly more frequent in children with mosquito allergy. Skin prick test with mosquito allergen was positive in only 6 children (6,4%). Grass pollen sensitization was most common in children (28.7%) followed by sensitization to house dust mite (9.6%). 30 children (31.9%) had an accompanying atopic disease such as allergic rhinitis, asthma or atopic dermatitis. Bullae were significantly more frequent in children with asthma (41.7% vs.15.9, p=0.034). The median duration of symptoms after onset were significantly longer in patients with ecchymosis, with immediate wheals and in children whose symptoms start in 20 min to 4 hours after mosquito bites. Conclusions: The role of commercially available tests in the diagnosis of children with mosquito allergy is limited. There is an association between unusual, large local or exaggerated reactions after mosquito bites and allergic diseases in children. The severity of reactions increases with age and particularly in children with atopic background

Background: Periostin has emerged as a novel biomarker in the pathogenesis of T helper 2-type allergic diseases in the last years. The aim of this study was to investigate the association of serum periostin levels with clinical features in children with asthma. Methods: Children with physician-diagnosed asthma who attended regularly to an outpatient pediatric allergy and asthma center were enrolled in the study along with control subjects. Asthma severity and control status of the patients were evaluated according to recent GINA guidelines. Results: A total of 158 children (125 with asthma and 33 age and sex-matched control subjects) with a median age of 10.2 years (range 5.9-17.0) were enrolled. Asthma severity was mild in 41 (32.8%), moderate in 63 (50.4%) and severe in 21 (16.8%) children. Children with asthma had significantly higher periostin levels than controls (53.1 ± 13.1 vs 43.0 ± 11.2 ng/mL; p < 0.001). The mean serum periostin levels of children with severe asthma (63.8 ± 10.8) were significantly higher than in children with moderate asthma (53.3 ± 12.7) and mild asthma (47.4 ± 11.1) (p < 0.001). Serum periostin levels were found to be significantly correlated with asthma severity (Spearman’s rho [r]=0.41, p < 0.001). Results of multivariable logistic regression analysis demonstrated an association between serum periostin levels and asthma severity in children (OR, 1.10; 95% CI, 1.04-1.15; p <0.001) Conclusion: Serum periostin levels may serve clinicians in identifying children with severe asthma.