Skin barrier disruption and dermal inflammation are key phenotypes of atopic dermatitis (AD). Staphylococcus aureus secretes extracellular vesicles (EVs), which are involved in AD pathogenesis. Here, we evaluated the role of EVs-associated α-hemolysin derived from S. aureus in AD pathogenesis. α-hemolysin production from S. aureus was detected using western blot analyses. The cytotoxic activity of α-hemolysin on HaCaT keratinocytes was evaluated by measuring cell viability after treating cells with soluble and EVs-associated α-hemolysin. To determine the type of cell death, HaCaT keratinocytes were stained with annexin V and 7-AAD. The in vivo effects of α-hemolysin were evaluated by application of soluble and EV-associated α-hemolysin on the mouse skin. The present study showed that increased α-hemolysin was produced by S. aureus colonized on AD patients compared to healthy subjects. α-hemolysin production was also related to AD severity. In addition, EV-associated α-hemolysin was more cytotoxic to HaCaT keratinocytes than soluble α-hemolysin, and α-hemolysin-negative EVs did not induce keratinocyte death. EV-associated α-hemolysin induced necrosis, but soluble α-hemolysin induced apoptosis of keratinocytes. In vivo, skin barrier disruption and epidermal hyperplasia were induced by soluble and EV-associated α-hemolysin. However, AD-like dermal inflammation was only caused by EV-associated α-hemolysin. Moreover, neither skin barrier disruption nor AD-like skin inflammation was induced by α-hemolysin-negative EVs. Taken together, α-Hemolysin secreted from S. aureus, particularly the EV-associated form, induces both skin barrier disruption and AD-like skin inflammation, suggesting that EV-associated α-hemolysin is a novel diagnostic and therapeutic target for the control of AD.

The present meta-analyses indicated the diagnostic potential of Feno measurement as a rule-in test for detecting CVA in adult patients with chronic cough. However, Feno measurement may not be useful to predict EB in nonasthmatic subjects with chronic cough. These findings warrant further studies to validate the roles of Feno measurement in clinical practice of patients with chronic cough.

Toxocariasis is one of the causes of eosinophilia in peripheral blood and provokes eosinophilic infiltration in internal organs. Extended studies on the prevalence and clinical characteristics of toxocariasis have been rare. The aim of this study is to evaluate the prevalence of toxocariasis in unknown eosinophilia and to analyze the efficacy of toxocara enzyme-linked immunosorbent assay (ELISA). We evaluated patients presenting with peripheral blood eosinophilia (>500 cells/microl or > or =10% of white blood cell count). After checking drug histories and the presence of allergic diseases and parasitic infections, specific serum IgG antibody to Toxocara canis larval antigen was measured by ELISA. Liver and lung involvement was also evaluated. One-hundred and three patients were evaluated, and the mean age was 50.9 years old. Seventy patients (68.0%) were diagnosed as having toxocariasis. The patients who had a history of raw liver eating had a higher incidence, and the patients with liver involvement had higher serum eosinophil cationic protein values. The eosinophil count was normalized in 7 of 16 treated patients and in 25 of 54 untreated patients. The mean improvement duration was 12 months. We concluded that the prevalence of toxocariasis was high in patients with unknown eosinophilia, and the toxocara ELISA was essential for evaluation of the causes of unknown eosinophilia.