H 1-antihistamines are widely used in the treatment of various allergic diseases, but there are still many challenges in the safe and rational use of H 1-antihistamines in pediatrics, and there is a lack of guidance on the prescription review of H 1-antihistamines for children.In this paper, suggestions are put forward from the indications, dosage, route of administration, pathophysiological characteristics of children with individual difference and drug interactions, so as to provide reference for clinicians and pharmacists.

Allergen immunotherapy(AIT)is considered the treatment capable of modifying the natural history of allergic respiratory disorders.The adverse reactions associated with AIT limit its clinical use in moderate to severe allergic asthma.Omalizumab is currently approved for the treatment of allergic asthma, chronic spontaneous urticaria, allergic rhinitis and other allergic diseases.A few trials have demonstrated the clinical efficacy of AIT and omalizumab combination therapy in children with moderate to severe allergic asthma.This review summarizes the research progress, mechanisma and application of omalizumab combined with AIT in children with moderate to severe allergic asthma.

Objective:In order to explore the impact of corona virus disease 2019(COVID-19)on the hospitalization of children with bronchiolitis and to improve clinicians′ understanding of the characteristics of bronchiolitis during the COVID-19 epidemic.Methods:This was a multicenter clinical study, and the data have been collected from 23 children′s medical centers in China.All the clinical data were retrospectively collected from children with bronchiolitis who were hospitalized at each study center from January 1, 2019 to December 31, 2021.The results included gender, age at hospitalization, length of stay, respiratory syncytial virus(RSV) test results, severity rating, ICU treatment, and the total number of children hospitalized with respiratory tract infection during the same period.The clinical data of children with bronchiolitis in 2019 before COVID-19 epidemic and in 2020、2021 during COVID-19 epidemic were statistically analyzed and compared.Results:According to a summary of data provided by 23 children′s medical centers, there were 4 909 cases of bronchiolitis in 2019, 2 654 cases in 2020, and 3 500 cases in 2021.Compared with 2019, the number of bronchiolitis cases decreased by 45.94% in 2020 and 28.70% in 2021.In 2019, 2020 and 2021, there were no significant differences in gender ratio, age, and duration of hospitalization.Compared with 2019, the ratio of bronchiolitis to the total number of hospitalizations for respiratory tract infection decreased significantly in 2020 and 2021( χ2=12.762, P<0.05; χ2=84.845, P<0.05).The proportion of moderate to severe bronchiolitis cases in both 2020 and 2021 was lower than that in 2019, and the difference was statistically significant ( χ2=4.054, P<0.05; χ2=8.109, P<0.05).There was no statistically significant difference in the proportion of bronchiolitis cases requiring ICU treatment between 2019, 2020, and 2021 ( χ2=1.914, P>0.05).In 2019, a total of 52.60%(2 582/4 909) of children with bronchiolitis underwent RSV pathogen testing, and among them, there were 708 cases with RSV positive, accounting for 28.00%.In 2020, 54.14%(1 437/2 654) of children with bronchiolitis underwent RSV pathogen testing, and there were 403 cases with RSV positive, accounting for 28.04%.In 2021, 66.80%(2 238/3 500) of children with bronchiolitis underwent RSV pathogen testing, and there were 935 cases with RSV positive, accounting for 41.78%.Compared with 2019 and 2020, the RSV positive rate in 2021 showed a significant increase( χ2=99.673, P<0.05; χ2=71.292, P<0.05). Conclusion:During the COVID-19 epidemic, the implementation of epidemic prevention and control measures reduced the hospitalization rate and severity of bronchiolitis, but did not reduce the positive rate of RSV detection.

China has classified the Corona Virus Disease 2019(COVID-19) as a statutory category B infectious disease and managed it according to Category B since January 8, 2023.In view that Omicron variant is currently the main epidemic strain in China, in order to guide the treatment of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection in children with the times, refer to the Diagnosis and Treatment Protocol for Novel Coronavirus Infection (Trial 10 th Edition), Expert Consensus on Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fourth Edition) and the Diagnosis and Treatment Strategy for Pediatric Related Viral Infections.The Expert Consensus on the Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fifth Edition) has been formulated and updated accordingly on related etiology, epidemiology, pathogenic mechanism, clinical manifestations, auxiliary examination, diagnosis and treatment, and added key points for the treatment of COVID-19 related encephalopathy, fulminating myocarditis and other serious complications for clinical reference.

Objective:To investigate the epidemiological and clinical characteristics of human parainfluenza viruses (HPIVs) infection among hospitalized children with community-acquired pneumonia (CAP) in China, and provide basic data for diagnosis, treatment and prevention of HPIVs infection.Methods:From November 2014 to February 2020, 5 448 hospitalized children with CAP were enrolled in 14 hospitals in 11 provinces and municipalities directly under the Central Government in southern China and northern China. Nasopharyngeal aspirates or throat swabs were collected, and the nucleic acids of 18 types respiratory viruses including HPIV1-4 were screened by suspension array technology. Demographic data and clinical information were collected for statistical analysis.Results:The total detection rate of HPIVs in 5 448 children with CAP was 8.83% (481/5 448), and the detection rate in males was higher than that in females (62.79% vs. 37.21%; χ2=0.000, P=0.992). The detection rate of HPIVs in 1~< 3 years age group was higher than that in other age groups, and the difference was statistically significant ( χ2=61.893, P<0.001). The detection rate of HPIVs in the northern region was higher than that in the southern region (9.02% vs 8.65%), but the difference was not statistically significant ( χ2=0.239, P=0.625). The prevalence of HPIV1-4 in northern and southern China was not completely same. HPIV1 was mainly prevalent in autumn in both northern and southern regions. HPIV2 was prevalent in summer in northern China, and the detection rate was low in southern China. HPIV3 reached its peak in both spring and summer in both northern and southern China, but its duration was longer in southern China than in northern China. HPIV4 is mainly popular in autumn in both southern China and northern China. Among 481 children infected with HPIVs, 58.42% (281/481) were infected with HPIV alone, and the main clinical manifestations were cough (90.75%) and fever (68.68%). Out of the HPIV-positive cases, 42.62% (205/481) were co-infected with another type of HPIV or a different virus, while 11.43% (55/481) had co-infections with two or more different viruses. HPIV3 was the most common type of co-infection with other viruses. HPIV3 infection accounted for the largest proportion (76.80%) in 47 HPIVs-positive children with severe pneumonia. Conclusions:HPIVs is one of the most important pathogens causing CAP in children in China, and children under 3 years of age are the main populations of HPIVs infection. The prevalence characteristics of all types of HPIVs in children in the north and south are not completely same. HPIV3 is the dominant type of HPIV infections and causes more severe diseases.

Airway epithelial damage, increased Th2 inflammatory response, and impaired immune regulatory T cell function are important mechanisms for the development of asthma.Indoleamine 2, 3-dioxygenase(IDO) is induced by LPS and IFN-γ, which regulates the differentiation of naive T cells into CD4 + CD25 + regulatory T cells(Treg)and induces immune tolerance.It can inhibit eosinophilic airway inflammation.Decreased IDO activity may promote the development of asthma.Tryptophan metabolites act on AhR receptors to promote the production of IL-22 and enhance the integrity of the epithelium and its resistance to infection.The Th17/Treg balance induced by specific immunotherapy could be altered, and Treg cell proliferation was observed.Tryptophan metabolites can reduce airway inflammation and inflammatory cytokine infiltration.D-tryptophan can promote the diversity of intestinal flora, increase the number of Treg in lung and colon, reduce Th2 reaction, and reduce airway hyperresponsiveness.Tryptophan and its metabolites, IDO and D-tryptophan play an important role in the occurrence, development and specific immunotherapy of asthma.

Thymic stromal lymphopoietin(TSLP)can enhance the secretion of type 2 cytokines by type 2 T helper(Th2)cells and type 2 innate iymphocytes(ILC2s)in the lung through direct and indirect action.In terms of indirect effects, TSLP can promote the proliferation and expansion of naive CD4 + T cells by using dendritic cells, and promote the recruitment of Th2 cells to the initial inflammatory site.It can also use stromal mononuclear/macrophages cells to start the acute primary Th2-dependent immune response.In the aspect of direct effect, TSLP can activate ILC2s before the adaptive immune response is initiated, and also can use immature T cells, effector Th2 cells and memory Th2 cells to participate in the adaptive immune response.Therefore, TSLP plays an important role in allergic immune response of lung.

Acute respiratory tract infection is the most common infectious disease in children, which seriously threatens children′s health.Rapid and accurate etiological diagnosis is of great significance for the clinical treatment and control of these diseases.Pathogen nucleic acid test was applied and became the main method of respiratory tract infection diagnosis for its high sensitivity and specificity.To regulate the application of pathogen nucleic acid amplification test in respiratory tract infection in children, improve the diagnosis level, expert consensus on nucleic acid amplification test of respiratory pathogens in children was prepared to guide the application and promote pathogens diagnosis ability.

In the state of disease, the mucin composition and fluid secretion of respiratory mucus change significantly, which changes the physical and chemical properties of mucus, so as to promote the progress of the disease.Respiratory mucus has different characteristics in different diseases, which is reflected in the formation mechanism, components, functions and so on.This paper mainly expounds the different characteristics of children′s respiratory mucus(especially mucus plug)in bronchial asthma, lower respiratory tract infection, cystic fibrosis and idiopathic pulmonary fibrosis.

Objective:To investigate clinical and bronchoscopy characteristics of Mycoplasma pneumoniae pneumonia in children with 23S rRNA resistance gene positive in bronchoalveolar lavage fluid(BALF), and find clinical indicators that can identify Mycoplasma pneumoniae drug resistance early.Methods:The clinical data of 61 hospita-lized children diagnosed with Mycoplasma pneumoniae pneumonia as subjects from October 2017 to June 2018 in the Department of Pediatric Respiratory Medicine of Shengjing Hospital Affiliated to China Medical University were analyzed retrospectively.Bronchoscopy was performed on each subject and the BALF was taken and used to detect the 2063 site mutation of the 23S rRNA V region gene in BALF, and they were divided into drug-resistant gene positive group and drug-resistant gene negative group.The clinical manifestations, relevant laboratory data, imaging data, and bronchoscopy findings in different load groups were compared.Statistical methods such as t test, rank sum test, χ2 test, Fisher′ s exact probability method, and multivariate Logistic regression analysis were used to analyze the data. Results:Among the 61 children, 38 cases (62.30%) were in the drug resistance gene positive group, and 23 cases (37.70%) were in the drug resistance gene negative group.There were no significant differences in gender and age between the two groups (all P>0.05). The days of hospitalization and fever in the children with positive drug resistance genes were longer than those in the negative drug resistance gene groups, and they were more likely to have refractory mycoplasma pneumoniae pneumonia(RMPP) and extra pulmonary complications, with statistically significant differences ( P<0.05), but there were no significant differences in hypoxemia ( P>0.05). There were significant differences in white blood cell(WBC), C-reactive protein(CRP), procalcitonin(PCT), D-Dimer (D-D) and interleukin-6 (IL-6) between the two groups (all P<0.05). Except that the WBC level in the drug-resistant gene-positive group was lower than that in the drug-resistant gene-negative group, the rest of the test results indicated that the drug-resistant gene-positive group was higher than the drug-resistant gene-negative group.There were no significant differences in the concentrations of serum lactate dehydrogenlase(LDH)and IL-6 in BALF ( P>0.05). In this study, Logistic regression analysis was performed on several statistically significant laboratory indicators.It was found that WBC was more sensitive to identify drug resistance genes, and the optimal critical value was 8.55×10 9/L.The specificity of D-D in identifying drug resistance genes was higher, and the optimal cut-off value was 523 μg/L.In the drug resistance gene positive group, 35 cases (92.11%) showed extensive lung consolidation/atelectasis on imaging, and the drug resistance gene negative group was 13 cases (56.52%), with statistically significant differences ( P<0.05). The drug resistance gene-positive group mainly showed mucosal erosion, necrosis, phlegm plug/plastic phlegm plug and bronchitis stenosis, with a total of 19 cases (50.00%). In the drug resistance gene negative group, the main manifestations of mucosal longitudinal wrinkle, flocculent and viscous secretions were 14 cases (60.88%), with statistically significant differences ( P<0.05). Conclusions:The point mutation of 23S rRNA V region gene is closely related to the clinical characteristics of children with Mycoplasma pneumoniae pneumonia.Children with A2063G mutation are more prone to have RMPP and extrapulmonary complications, and their imaging manifestation and bronchoscopy are more severe.The levels of leukocytes and D-D in the blood have significance for the early identification of drug resistance.The systemic excessive immune inflammatory response caused by Mycoplasma pneumoniae pneumonia with drug-resistant gene positive needs to be valued.