Clinical Characteristics of Macrolide-Refractory Mycoplasma pneumoniae Pneumonia in Korean Children: A Multicenter Retrospective Study.

Mycoplasma pneumoniae is a major causative pathogen of community-acquired pneumonia in children, and the treatment of choice is macrolides. There is an increasing trend in reports of refractory clinical responses despite macrolide treatment due to the emergence of macrolide-resistant M. pneumoniae. Early discrimination of macrolide-refractory M. pneumoniae pneumonia (MrMP) from macrolide-sensitive M. pneumoniae pneumonia (MSMP) is vital; however, testing for macrolide susceptibility at the time of admission is not feasible. This study aimed to identify the characteristics of MrMP in Korean children, in comparison with those of MSMP. In this multicenter study, board-certified pediatric pulmonologists at 22 tertiary hospitals reviewed the medical records from 2010 to 2015 of 5294 children who were hospitalized with M. pneumoniae pneumonia and administered macrolides as the initial treatment. One-way analysis of variance and the Kruskal-Wallis test were used to compare differences between groups. Of 5294 patients (mean age, 5.6 years) included in this analysis, 240 (4.5%), 925 (17.5%), and 4129 (78.0%) had MrMP, macrolide-less effective M. pneumoniae pneumonia, and MSMP, respectively. Compared with the MSMP group, the MrMP group had a longer fever duration, overall (13.0 days) and after macrolide use (8.0 days). A higher proportion of MrMP patients had respiratory distress, pleural effusion, and lobar pneumonia. The mean aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and C-reactive protein levels were the highest in the MrMP group, along with higher incidences of extrapulmonary manifestations and atelectasis (during and post infection). Pre-existing conditions were present in 17.4% (n = 725/4159) of patients, with asthma being the most common (n = 334/4811, 6.9%). This study verified that MrMP patients show more severe initial radiographic findings and clinical courses than MSMP patients. MrMP should be promptly managed by agents other than macrolides.

Annual and seasonal patterns in etiologies of pediatric community-acquired pneumonia due to respiratory viruses and Mycoplasma pneumoniae requiring hospitalization in South Korea.

BACKGROUND: Community-acquired pneumonia (CAP) is one of the leading worldwide causes of childhood morbidity and mortality. Its disease burden varies by age and etiology and is time dependent. We aimed to investigate the annual and seasonal patterns in etiologies of pediatric CAP requiring hospitalization. METHODS: We conducted a retrospective study in 30,994 children (aged 0-18 years) with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Mycoplasma pneumoniae (MP) pneumonia was clinically classified as macrolide-sensitive MP, macrolide-less effective MP (MLEP), and macrolide-refractory MP (MRMP) based on fever duration after initiation of macrolide treatment, regardless of the results of in vitro macrolide sensitivity tests. RESULTS: MP and respiratory syncytial virus (RSV) were the two most commonly identified pathogens of CAP. With the two epidemics of MP pneumonia (2011 and 2015), the rates of clinical MLEP and MRMP pneumonia showed increasing trends of 36.4% of the total MP pneumonia. In children < 2 years of age, RSV (34.0%) was the most common cause of CAP, followed by MP (9.4%); however, MP was the most common cause of CAP in children aged 2-18 years of age (45.3%). Systemic corticosteroid was most commonly administered for MP pneumonia. The rate of hospitalization in intensive care units was the highest for RSV pneumonia, and ventilator care was most commonly needed in cases of adenovirus pneumonia. CONCLUSIONS: The present study provides fundamental data to establish public health policies to decrease the disease burden due to CAP and improve pediatric health.

Severe Cutaneous Adverse Reactions in Korean Pediatric Patients: A Study From the Korea SCAR Registry.

PURPOSE: Although severe cutaneous adverse drug reactions (SCARs) are rare, they are associated with high morbidity and mortality, and thus early diagnosis and treatment are critical for improving prognoses. However, few studies have reported the characteristics of SCARs in children. Thus, we aimed to evaluate the clinical characteristics, current management and prognosis of pediatric SCARs. METHODS: We analyzed pediatric data in the Korean SCARs registry, which was built retrospectively in 2016 with SCAR cases treated in 34 tertiary referral university hospitals during 2010-2015. Using these cases, we descriptively analyzed detailed data regarding etiology, clinical and laboratory features, treatment strategies, and prognosis. RESULTS: Forty-seven pediatric SCAR cases from 15 tertiary referral hospitals were included. The median patient age was 10 (interquartile range, 3-15.5) years and 68.1% (n = 32) were males. The culprit drug was identified in 95.7% (n = 45) of the patients; antibiotics (44.7%) and antiepileptic drugs (19.1%) were the most common and second most common culprits, respectively. Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) cases presented with the largest area of skin involvement without permanent sequelae. Stevens-Johnson syndrome (SJS) cases involved relatively small areas of skin but serious sequelae in two children. Of 4 patients with toxic epidermal necrolysis (TEN), 1 died. Of all patients assessed, 36 (76.6%) received systemic steroids and 21 (44.7%) received intravenous immunoglobulin (IVIG). Thirteen (27.7%) received both systemic steroids and IVIG. Cyclosporine was administered to only 1 patient along with a systemic steroid. CONCLUSIONS: In patients with pediatric SCARs, including those with DRESS, SJS and TEN, clinical presentations were variable. Thus, there was no clear continuous disease spectrum. Although the mortality rate was low (2.1%), clinical suspicion may be the best tool for proactive SCAR management.

Lymphocyte-monocyte ratio at day 14 of first cisplatin-doxorubicin chemotherapy is associated with treatment outcome of pediatric patients with localized osteosarcoma.

PURPOSE: We aimed to determine the prognostic significance of lymphocyte counts and the lymphocytemonocyte ratio (LMR) in pediatric patients with osteosarcoma. METHODS: We retrospectively reviewed the medical records of 27 pediatric patients with localized extremity osteosarcoma, treated at the Korea Cancer Center Hospital between May 2002 and March 2016. Leukocyte counts and LMR before treatment and on day 14 (LMR14) of the first cisplatin-doxorubicin chemotherapy round were evaluated. Patients were dichotomized according to the median value of these parameters, and survival rates were compared. RESULTS: The median age of the 27 patients was 9.9 years (range, 3.2-14.1 years) and tumor sites were: distal femur (n=14), proximal humerus (n=7), proximal tibia (n=2), proximal fibula (n=2), and elsewhere (n=2). Patients were followed up on for a median of 76.4 months (range, 4.5-174.7 months), and 5-year overall (OS) and event-free survival (EFS) rates were 66.0%±9.8% and 60.9%±9.7%, respectively. Patients with a higher pretreatment lymphocyte count (≥2,320/µL) had better OS (90.9% vs. 46.2%, P=0.04) and EFS (83.9% vs. 38.5%, P=0.02). However, the day 14 lymphocyte count was not associated with survival. While no survival difference was observed between patients grouped according to pretreatment LMR (median value, 6.3), patients with a higher LMR14 (≥5) fared better than those with lower LMR14 (5-year OS: 83.3% vs. 46.3%, P=0.04). CONCLUSION: Pretreatment lymphocyte count and LMR during chemotherapy had prognostic significance in pediatric osteosarcoma patients. Further studies involving larger cohorts are necessary to validate our findings.

Evaluation of the field-protective effectiveness of seasonal influenza vaccine among Korean children aged < 5 years during the 2014-2015 and 2015-2016 influenza seasons: a cohort study.

BACKGROUND: A field effectiveness evaluation of the influenza vaccine among children younger than five years is important due to the high burden of influenza in this age group. The epidemiology of influenza virus changes rapidly each year. Moreover, the development of a new type of influenza vaccine is accelerating, necessitating a new field effectiveness evaluation. METHODS: This multi-center, open-label cohort study was conducted in the northern part of Seoul from December 2014 to May 2015 and in Gyeong-gi Province from December 2015 to May 2016. The cohort comprised an influenza vaccinated group and non-vaccinated group. During the influenza seasons, we conducted influenza rapid tests and polymerase chain reaction assays for individuals with suspected influenza and checked for the presence of influenza virus. We calculated the influenza vaccine effectiveness by comparing the incidence rates of influenza between the vaccinated and non-vaccinated groups. RESULTS: During the 2014-2015 season, the field effectiveness of the influenza vaccine was 38.4%. In particular, the vaccine effectiveness against type A influenza virus was 50.7%. During the 2015-2016 season, the vaccine effectiveness reached 23.8% and the vaccine effectiveness against type A influenza virus was 48.5%. The vaccine effectiveness against influenza B virus was markedly reduced in both seasons. CONCLUSION: The influenza vaccine was supposed to be effective against influenza A, but may have a limited effectiveness against influenza B among Korean children aged < 5 years.

Reference values for serum ferritin and percentage of transferrin saturation in Korean children and adolescents.

BACKGROUND: Ferritin reference values vary by age, gender, and ethnicity. We aimed to determine reference values of serum ferritin (SF) and the percentage of transferrin saturation (TSAT) for Korean children and adolescents. METHODS: We analyzed data from 2,487 participants (1,311 males and 1,176 females) aged 10-20 years from the Korea National Health and Nutrition Examination Survey (2010-2012). We calculated age- and gender-stratified means and percentile values for SF and TSAT. RESULTS: We first plotted mean SF and TSAT by gender and according to age. In males, mean SF tended to be relatively constant among participants aged 10 to 14 years, with an upward trend thereafter. Mean SF trended downward among female participants until the age of 15 years and remained constant thereafter. Thus, significant gender differences in ferritin exist from the age of 14 years. High levels of SF were associated with obesity, and lower SF levels were associated with anemia and menarche status. CONCLUSION: We established reference values of SF and TSAT according to age and gender. The reference values for SF calculated in this study can be used to test the association between SF values and other defined diseases in Korean children and adolescents.

Thromboembolic events identified during diagnosis of germ cell tumors in 2 children.

We describe 2 cases in which radiographic evidence of thromboembolic events was obtained during germ cell tumor diagnosis. There was no evidence of coagulation factor abnormalities or contributory procedures or drugs in either patient. We used anticoagulation therapy for thrombolysis in one patient, but in the other, the thromboembolism resolved spontaneously.