Real-world treatment pattern of mycoplasma pneumonia in hospitalized children: A multicenter retrospective study

Purpose@#Macrolide-refractory Mycoplasma pneumoniae pneumonia (MP) has markedly increased since 2003 and corticosteroids or second-line antibiotics, such as fluoroquinolones or tetracyclines, was considered an alternative treatment modality in macrolide-refractory MP. We aimed to show the real-world treatment pattern of MP in hospitalized children and compared clinical and laboratory findings between children with and without steroid treatment. @*Methods@#We reviewed the medical records of 384 children diagnosed with MP from 6 hospitals in Korea from August 2015 to March 2016. We investigated the clinical, laboratory and radiologic findings, and medications used for the treatment of the subjects. @*Results@#The corticosteroids and second-line antibiotics were administered in 55.5% and 7.0%, respectively. The percentages of steroid administration varied from 17% to 69% in each hospital. The mean start date of corticosteroid administration was 3.4 hospital days. Patients with corticosteroid treatment had a longer length of hospital stay than those without corticosteroid. They exhibited higher rates of lobar pneumonia and pleural effusion, and required longer days until improvement in chest X-ray findings. They also had higher rates of allergic diseases and showed higher C-reactive protein levels at admission. @*Conclusion@#In the real-world practice studied in the 6 hospitals, corticosteroids were more frequently administered than second-line antibiotics to hospitalized children with MP. Children with corticosteroid adjuvant therapy had more severe pneumonia than those without. Randomized controlled trials are needed to make appropriate guidelines for macrolide-refractory MP.

Trends of Sensitization to Inhalant Allergens in Korean Children Over the Last 10 Years

Purpose@#Climate and lifestyle changes increase an individual’s susceptibility to various allergens and also the incidence of allergic diseases. We aimed to examine the changes in sensitization rate for aeroallergens over a 10-year period in Korean children. @*Materials and Methods@#We retrospectively reviewed the medical records of 4493 children who visited the allergy clinic at a tertiary hospital in Korea for allergic rhinitis or asthma from January 2009 to December 2018. The serum specific immunoglobulin E (IgE) levels were measured to confirm the sensitization against Dermatophagoides farinae (D. farinae), Alternaria, weed and tree pollen mixtures, as well as cat and dog dander through ImmunoCAP test. @*Results@#D. farinae was the most common sensitizing aeroallergen (45.9%) during the 10-year span. The sensitization rate for tree pollen mixture (p for trend <0.001), weed pollen mixtures (p for trend <0.001), dog dander (p for trend=0.025), and cat dander (p for trend=0.003) showed ascending trends during the 10-year study period. Furthermore, the sensitization rate for multiple allergens (≥2) in 2018 increased significantly compared to that in 2009 (p for trend=0.013).Compared with children without sensitization to D. farinae, those with sensitization to D. farinae showed higher sensitization rates to other aeroallergens (p for interaction <0.001). @*Conclusion@#Children’s sensitization rate to cat and dog dander and weed and tree pollen mixtures significantly increased during the 10-year period in Korea. Children with sensitization to D. farinae are likely to be sensitized to other aeroallergens as well.

A Case of Von Hippel-Lindau Disease Presented with Multiple Pancreatic Cysts and Medullary Hemangioblastoma / 임상소아혈액종양

Von Hippel-Lindau (VHL) disease is a rare inherited cancer predisposition syndrome characterized by benign and malignant tumors in multiple organs, especially cerebellar hemangioblastomas, retinal angiomas, renal-cell carcinoma, and pheochromocytomas. Clinically, VHL disease also presents an increased risk for developing multiple visceral cysts in the pancreas, liver, and kidneys. Regular surveillance for VHL disease-associated tumors after early diagnosis is necessary for better outcomes in VHL disease. An 11-year-old girl was admitted with prolonged fever lasting for more than 10 days and cervical lymphadenopathy. She did not have a family history of cysts or malignancy. Initial blood tests showed mild leukopenia and moderate elevation in aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, but with normal amylase and lipase. Hepatobiliary ultrasonography and magnetic resonance cholangiopancreatography were done and revealed multiple cysts involving the whole pancreas with cyst sizes up to 1.6 cm, indicating VHL disease. Direct sequencing of the VHL gene showed a heterozygous duplication at codon 384 (c.384dup), which is predicted to cause a frameshift of the reading frame (p.Leu129Serfs*3). This was a novel pathogenic variant VHL gene. We carried out the surveillance protocol for VHL disease-associated tumors, and found a hemangioblastoma in the medulla of the brainstem. We are reporting an 11-year-old female patient of VHL disease with brainstem hemangioblastoma who could be suspected and diagnosed of VHL disease in asymptomatic state due to incidentally found multiple pancreatic cysts.

Multisystem Inflammatory Syndrome in Children Related to COVID-19: the First Case in Korea

Since mid-April 2020, cases of multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 that mimics Kawasaki disease (KD) have been reported in Europe and North America. However, no cases have been reported in Korea.We describe an 11-year old boy with fever, abdominal pain, and diarrhea who developed hypotension requiring inotropes in intensive care unit. His blood test revealed elevated inflammatory markers, thrombocytopenia, hypoalbuminemia, and coagulopathy. Afterward, he developed signs of KD such as conjunctival injection, strawberry tongue, cracked lip, and coronary artery dilatation, and parenchymal consolidation without respiratory symptoms. Microbiological tests were all negative including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction.However, serum immunoglobulin G against SARS-CoV-2 was positive in repeated tests using enzyme-linked immunosorbent assay and fluorescent immunoassay. He was recovered well after intravenous immunoglobulin administration and discharged without complication on hospital day 13. We report the first Korean child who met all the criteria of MIS-C with features of incomplete KD or KD shock syndrome.

Relationship between Breastfeeding, Birth History, and Acute Pyelonephritis in Infants

BACKGROUND: Although the clinical importance of the immunological benefits of breastfeeding has been emphasized for decades, their direct relationship with acute pyelonephritis (APN) is still not clear. Our goal was to determine whether breastfeeding truly provides protection against APNs, while investigating the effects of other factors such as sex, age, mode of delivery, and birth weight on APN.METHODS: A total of 62 infants under 6 months of age who had both microbiologically and radiologically-confirmed APN were enrolled in the case group. Healthy infants (n = 178) who visited the hospital for scheduled vaccinations were enrolled in the control group. The following participant characteristics were compared between the case and control groups: age, sex, birth order among siblings, feeding methods, weight percentile by month, birth weight percentile by gestational age, gestational age at birth, and mode of delivery.RESULTS: Babies exclusively fed with manufactured infant formulae before 6 months of age had significantly higher risk for APN than breastfed or mixed-fed infants (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.687–7.031; P = 0.001). Firstborn babies had lower risk for APN than 2nd- or 3rd-born babies (OR, 0.43; 95% CI, 0.210–0.919). Other factors that increased the risk for APN were low birth weight percentiles (OR, 8.33; 95% CI, 2.300–30.166) and birth via caesarean section (OR, 2.32; 95% CI, 1.097–4.887). There were more preterm births in the case group (10.9% vs. 1.7%; P = 0.002), but this did not increase the risk for APN (OR, 4.47; P = 0.063).CONCLUSION: Feeding exclusively with formula before 6 months of age was related to higher risk for APN, which demonstrates that breastfeeding has a protective effect against APN. The other risk factors for APN were birth order (≥ 2nd-born), low birth weight, and birth via caesarean section.

Relationship between Breastfeeding, Birth History, and Acute Pyelonephritis in Infants

BACKGROUND@#Although the clinical importance of the immunological benefits of breastfeeding has been emphasized for decades, their direct relationship with acute pyelonephritis (APN) is still not clear. Our goal was to determine whether breastfeeding truly provides protection against APNs, while investigating the effects of other factors such as sex, age, mode of delivery, and birth weight on APN.@*METHODS@#A total of 62 infants under 6 months of age who had both microbiologically and radiologically-confirmed APN were enrolled in the case group. Healthy infants (n = 178) who visited the hospital for scheduled vaccinations were enrolled in the control group. The following participant characteristics were compared between the case and control groups: age, sex, birth order among siblings, feeding methods, weight percentile by month, birth weight percentile by gestational age, gestational age at birth, and mode of delivery.@*RESULTS@#Babies exclusively fed with manufactured infant formulae before 6 months of age had significantly higher risk for APN than breastfed or mixed-fed infants (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.687–7.031; P = 0.001). Firstborn babies had lower risk for APN than 2nd- or 3rd-born babies (OR, 0.43; 95% CI, 0.210–0.919). Other factors that increased the risk for APN were low birth weight percentiles (OR, 8.33; 95% CI, 2.300–30.166) and birth via caesarean section (OR, 2.32; 95% CI, 1.097–4.887). There were more preterm births in the case group (10.9% vs. 1.7%; P = 0.002), but this did not increase the risk for APN (OR, 4.47; P = 0.063).@*CONCLUSION@#Feeding exclusively with formula before 6 months of age was related to higher risk for APN, which demonstrates that breastfeeding has a protective effect against APN. The other risk factors for APN were birth order (≥ 2nd-born), low birth weight, and birth via caesarean section.

Relationship between Breastfeeding, Birth History, and Acute Pyelonephritis in Infants

BACKGROUND@#Although the clinical importance of the immunological benefits of breastfeeding has been emphasized for decades, their direct relationship with acute pyelonephritis (APN) is still not clear. Our goal was to determine whether breastfeeding truly provides protection against APNs, while investigating the effects of other factors such as sex, age, mode of delivery, and birth weight on APN.@*METHODS@#A total of 62 infants under 6 months of age who had both microbiologically and radiologically-confirmed APN were enrolled in the case group. Healthy infants (n = 178) who visited the hospital for scheduled vaccinations were enrolled in the control group. The following participant characteristics were compared between the case and control groups: age, sex, birth order among siblings, feeding methods, weight percentile by month, birth weight percentile by gestational age, gestational age at birth, and mode of delivery.@*RESULTS@#Babies exclusively fed with manufactured infant formulae before 6 months of age had significantly higher risk for APN than breastfed or mixed-fed infants (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.687–7.031; P = 0.001). Firstborn babies had lower risk for APN than 2nd- or 3rd-born babies (OR, 0.43; 95% CI, 0.210–0.919). Other factors that increased the risk for APN were low birth weight percentiles (OR, 8.33; 95% CI, 2.300–30.166) and birth via caesarean section (OR, 2.32; 95% CI, 1.097–4.887). There were more preterm births in the case group (10.9% vs. 1.7%; P = 0.002), but this did not increase the risk for APN (OR, 4.47; P = 0.063).@*CONCLUSION@#Feeding exclusively with formula before 6 months of age was related to higher risk for APN, which demonstrates that breastfeeding has a protective effect against APN. The other risk factors for APN were birth order (≥ 2nd-born), low birth weight, and birth via caesarean section.

Seasonal patterns and etiologies of croup in children during the period 2010–2015: A multicenter retrospective study

PURPOSE: Croup is known to have epidemics in seasonal and biennial trends, and to be strongly associated with epidemics of parainfluenza virus. However, seasonal and annual epidemics of croup have not been clearly reported in Korea. This study aimed to examine the seasonal/annual patterns and etiologies of childhood croup in Korea during a consecutive 6-year period. METHODS: Pediatric croup data were collected from 23 centers in Korea from 1 January 2010 to 31 December 2015. Electronic medical records, including multiplex reverse transcription polymerase chain reaction (RT-PCR) results, demographics and clinical information were cross-sectionally reviewed and analyzed. RESULTS: Overall, 2,598 childhood croup patients requiring hospitalization were identified during the study period. Among them, a total of 927 who underwent RT-PCR were included in the analysis. Males (61.5%) predominated, and most (63.0%) of them were younger than 2 years of age (median, 19 months; interquartile range, 11–31 months). Peak hospitalization occurred in 2010 and 2012 in even-numbered years, and parainfluenza virus (PIV, 39.7%) was the most common cause of childhood croup requiring hospitalization, followed by respiratory syncytial virus (14.9%), human rhinovirus (12.5%), Mycoplasma pneumonaie (10.6%), and human coronavirus (7.3%). CONCLUSION: It is concluded that croup hospitalization has a biennial pattern in even-numbered years. PIV may be the most common cause of childhood croup; however, croup epidemics could be attributed to other viruses.

Multicenter Adherence Study of Asthma Medication for Children in Korea

PURPOSE: Adherence is a major component of successful medical treatment. However, non-adherence remains a barrier to effective delivery of healthcare worldwide. METHODS: Twenty healthcare facilities (secondary or tertiary hospitals) belonging to the Korean Academy of Pediatric Allergy and Respiratory Diseases (KAPARD) participated. Questionnaires were given to patients currently receiving treatment in the form of inhalant useor oral intake or transdermal patch for mild to moderate asthma. RESULTS: A total of 1,838 patients responded to the questionnaire. Mean age was 5.98 ± 3.79 years (range: 0-18 years). With help from their caregivers, the percentage of patients that answered “taking as prescribed” was 38.04% for inhalant users, 50.09% for oral medication users and 67.42% for transdermal users. Transdermal patch users had significantly greater adherence compared to the other 2 groups (P < 0.001). The 34.15% of inhalant users, 70.33% of oral medication users and 93.00% of transdermal patch users felt that their medication delivery system was “Easy” or “Very easy” to use (P < 0.001). “Method of administration” was deemed to be the most difficult part of the treatment regimen to follow, and 76.7% of patients preferred once-daily administration (i.e., “Frequency of administration”). CONCLUSIONS: Asthma medication adherence in young children was found to be better in the transdermal patch group. This may be due to requiring fewer doses and easy to follow instructions. From an adherence point of view, the transdermal patch seems more useful for long-term asthma control in children compared to oral or inhaled medicine.

Literature review and future strategies of childhood respiratory diseases in Korea

Thirty years have passed since the Korean Association of Pediatric Allergy and Respiratory Disease was founded. There have been great changes in the pattern of respiratory diseases in Korean children during the last 30 years with economic development in the country. Pneumonia remains the leading cause of childhood morbidity, despite advances in the prevention and management. The incidence and mortality of pneumonia caused by typical bacterial pathogens have been reduced. However, the predominance of Mycoplasma pneumoniae or virus-associated diseases is emerging, which suggests that novel diagnostic and therapeutic strategies are needed. Viral bronchiolitis is one of the most substantial health burdens for infants and young children worldwide. Although respiratory syncytial virus is the most common pathogen, molecular diagnostic techniques have identified many other viruses including human rhinovirus causing bronchiolitis. Bronchiectasis is a chronic respiratory condition characterized by chronic infection, airway inflammation, and progressive lung function decline. Research into the interactions between early life respiratory infections and development of bronchiectasis is imperative to halt the disease in its origin and improve adult outcomes. Acute respiratory distress syndrome (ARDS) is a severe, life-threatening lung disease with diffuse inflammatory lung injury leading to pulmonary edema and hypoxia. Although many modalities to treat ARDS have been studied, supportive therapies and lung protective ventilator support remains the mainstay. This review focuses on the current trends in research on these childhood respiratory diseases through literature review and aims to investigate the impact of Korean study results in this field.

Increased procalcitonin level is a risk factor for prolonged fever in children with Mycoplasma pneumonia / 소아과

PURPOSE: Macrolide-resistant Mycoplasma pneumoniae pneumonia (MPP) is characterized by prolonged fever and radiological progression despite macrolide treatment. Few studies have examined serum procalcitonin (PCT) level in children with MPP. We aimed to investigate the association of acute inflammation markers including PCT with clinical parameters in children with MPP. METHODS: A total of 147 children were recruited. The diagnosis of MPP relied on serial measurement of IgM antibody against mycoplasma and/or polymerase chain reaction. We evaluated the relationships between C-reactive protein (CRP), PCT, and lactate dehydrogenase (LDH) levels and white blood cell (WBC) counts, and clinical severity of the disease. We used multivariate logistic regression analysis to estimate the odds ratio for prolonged fever (>3 days after admission) and hospital stay (> 6 days), comparing quintiles 2–5 of the PCT levels with the lowest quintile. RESULTS: The serum PCT and CRP levels were higher in children with fever and hospital stay than in those with fever lasting ≤ 3 days after admission and hospital stay ≤ 6 days. CRP level was higher in segmental/lobar pneumonia than in bronchopneumonia. The LDH level and WBC counts were higher in children with fever lasting for >3 days before compared to those with fever lasting for ≤ 3 days. The highest quintile of PCT levels was associated with a significantly higher risk of prolonged fever and/or hospital stay than the lowest quintile. CONCLUSION: Serum PCT and CRP levels on admission day were associated with persistent fever and longer hospitalization in children with MPP.

Mutation Analysis of X-linked Sideroblastic Anemia in a 12-Month-Old Boy by Massively Parallel Sequencing

No abstract available.

Relationship of serum vitamin D and interleukin-31 levels to allergic or nonallergic rhinitis in children

PURPOSE: Serum vitamin D (25-hydroxyvitamin D, 25[OH] D) and interleukin-31 (IL-31) are related to atopic dermatitis, but their relationship with allergic rhinitis is unclear. The purpose of this study was to compare the levels of serum IL-31 and 25 (OH) D between the allergic rhinitis (AR), nonallergic rhinitis (NAR), and control groups and to investigate the relationship between IL-31 and 25 (OH) D. METHODS: We recruited 59 children with only rhinitis and 33 controls without any allergic diseases. Serum IL-31 and 25(OH) D levels were assayed using an enzyme-linked immunosorbent assay and high-performance liquid chromatography, respectively. The patients were considered to have atopic sensitization if the levels of serum specific IgE to inhalant allergens as assessed using immunoCAP were ≥0.35 IU/mL or if they tested positive for one or more allergens by the skin prick test. RESULTS: Of children with rhinitis, 25 had nonatopy (NAR), and 34 children had atopy (AR). Serum 25(OH) D levels were significantly lower in the rhinitis group than in the control group, while there was no significant difference serum 25(OH) D levels between the AR and NAR groups. Children with rhinitis demonstrated higher serum IL-31 levels than controls; however, there was no difference in serum IL-31 levels between the AR and NAR groups. Serum 25(OH) D levels were inversely correlated with serum IL-31 levels and blood eosinophil counts. On the other hand, serum 25(OH) D levels were not correlated with total serum IgE levels. CONCLUSION: Serum 25(OH) D and IL-31 may play a role in the pathogenesis of rhinitis via mechanisms other than IgE-related pathway.

Acute Gastritis and Splenic Infarction Caused by Epstein-Barr Virus / 대한소아소화기영양학회지

Epstein-Barr virus (EBV) infection can be presented with various clinical manifestations and different levels of severity when infected. Infectious mononucleosis, which is most commonly caused by EBV infection in children and adolescents, is a clinical syndrome characterized by fatigue, malaise, fever, sore throat, and generalized lymphadenopathy. But rarely, patients with infectious mononucleosis may present with gastrointestinal symptoms and complicated by gastritis, splenic infarction, and splenic rupture. We encountered a 16-year-old girl who presented with fever, fatigue, and epigastric pain. Splenic infarction and EBV-associated gastritis were diagnosed by using esophagogastroduodenoscopy and abdominal computed tomography. Endoscopy revealed a generalized hyperemic nodular lesion in the stomach, and the biopsy findings were chronic gastritis with erosion and positive in situ hybridization for EBV. As splenic infarction and acute gastritis are rare in infectious mononucleosis and are prone to be overlooked, we must consider these complications when an infectious mononucleosis patient presents with gastrointestinal symptom.

Allergic Rhinitis in Preschool Children and the Clinical Utility of FeNO

PURPOSE: The nature of allergic rhinitis (AR) in preschool aged children remains incompletely characterized. This study aimed to investigate the prevalence of AR and its associated risk factors in preschool-aged children and to assess the clinical utility of fractional exhaled nitric oxide (FeNO). METHODS: This general population-based, cross-sectional survey included 933 preschool-aged (3- to 7-year-old) children from Korea. Current AR was defined as having nasal symptoms within the last 12 months and physician-diagnosed AR. RESULTS: The prevalence of current AR in preschool children was 17.0% (156/919). Mold exposure (adjusted odds ratio [aOR], 1.67; 95% confidence interval [CI], 1.15-2.43) and the use of antibiotics (aOR, 1.97; 95% CI, 1.33-2.90) during infancy were associated with an increased risk of current AR, whereas having an older sibling (aOR, 0.52; 95% CI, 0.35-0.75) reduced the risk. Children with current atopic AR had significantly higher geometric mean levels of FeNO compared to those with non-atopic rhinitis (12.43; range of 1standard deviation [SD], 7.31-21.14 vs 8.25; range of 1SD, 5.62-12.10, P=0.001) or non-atopic healthy children (8.58; range of 1SD, 5.51-13.38, P<0.001). The FeNO levels were higher in children with current atopic AR compared with atopic healthy children (9.78; range of 1SD, 5.97-16.02, P=0.083). CONCLUSIONS: Mold exposure and use of antibiotics during infancy increases the risk of current AR, whereas having an older sibling reduces it. Children with current atopic AR exhibit higher levels of FeNO compared with non-atopic rhinitis cases, suggesting that FeNO levels may be a useful discriminatory marker for subtypes of AR in preschool children.

Clinical characteristics of Mycoplasma pneumoniae pneumonia in Korean children during the recent 3 epidemics

PURPOSE: Mycoplasma pneumoniae (MP) is a major cause of community-acquired pneumonia in children. Since 2000, emerging macrolide-resistant MP has been reported. Three epidemics of MP pneumonia have occurred in Korea during the past 10 years: 2006–2007, 2011, and 2015. We investigated the differences in MP pneumonia of each epidemic in terms of clinical, laboratory, and radiologic perspectives. METHODS: We retrospectively analyzed 529 medical records of children (1–18 years of age) who were admitted and diagnosed with MP pneumonia at Kangbuk Samsung Hospital during the past 3 epidemic periods. We compared the clinical, laboratory, and radiologic characteristics of MP pneumonia among individual epidemics and between children younger and older than 6 years of age. RESULTS: The mean age of the patients was 5.7 years old, which had increased by each epidemic and showed the highest (6.3 years old) in 2015 compared to previous epidemics. Among 3 epidemics, there were no sex differences. The duration of fever after admission and hospitalization, and the percentage of lobar pneumonia and use of systemic steroids increased significantly in 2015 epidemic. Since 2006, the mean levels of erythrocyte sedimentation rate and lactate dehydrogenase had increased and in 2015 it marked the highest. Children older than 6 years showed a higher proportion of lobar pneumonia and pleural effusion as well as longer duration of fever (before and after admission) and hospitalization days than those younger than 6 years. CONCLUSION: This study suggests an increasing incidence of refractory MP pneumonia which required a more frequent use of systemic steroids over the past 10 years, and children older than 6 years were found to have more severe pneumonia than those younger than 6 years.

Risk factors for latent tuberculosis in children who had close contact to households with pulmonary tuberculosis

PURPOSE: Tuberculosis (TB) is a common and possibly fatal infectious disease, and its incidence and prevalence is quite high in Korea compared to other Organization for Economic Co-operation and Development countries. Patients who have active TB can cause latent tuberculosis infection (LTBI) in children, which may progress to reactivated tuberculosis. This study was performed to analyze the risk of adult TB that affects children's LTBI. METHODS: From June 2013 to May 2014, 60 children (32 boys, 28 girls) who came into close contact with adult patients diagnosed with pulmonary TB underwent LTBI tests. The children were divided into the 2 groups: the first group was finally diagnosed to LTBI, and the second group was proven not to have LTBI. We compared the risk of adult patients with pulmonary TB between children with LTBI and those without through a medical record review. RESULTS: The number of adult patients with TB was 36 (father 68%, mother 23%, grandparents 8%). The patients who came into close contact with the LTBI group were older (47.0±12.8 years vs. 41.3±6.6 years) and had higher erythrocyte sedimentation rate (ESR) levels than those of the second group. The rate of negative acid-fast-bacilli smear with positive culture results in patients who came into contact with the LBTI group was higher than in the second group. The cutoff value of ESR for the diagnosis of LTBI was 31 mm/hr with a sensitivity of 0.75 and a specificity of 0.85 (area under curve=0.748). CONCLUSION: Adult pulmonary TB patients who are older and have higher ESR levels may be risk factors for LTBI in children coming into close contact with them.

Mechanism of resistance acquisition and treatment of macrolide-resistant Mycoplasma pneumoniae pneumonia in children / 소아과

Mycoplasma pneumoniae pneumonia (MPP) is one of the most common forms of community-acquired pneumonia in children and adolescents. Outbreaks of MPP occur in 3- to 7-year cycles worldwide; recent epidemics in Korea occurred in 2006–2007, 2011, and 2015–2016. Although MPP is known to be a mild, self-limiting disease with a good response to macrolides, it can also progress into a severe and fulminant disease. Notably, since 2000, the prevalence of macrolide-resistant MPP has rapidly increased, especially in Asian countries, recently reaching up to 80%–90%. Macrolide-resistant Mycoplasma pneumoniae (MRMP) harbors a point mutation in domain V of 23S rRNA with substitutions mainly detected at positions 2063 and 2064 of the sequence. The excessive use of macrolides may contribute to these mutations. MRMP can lead to clinically refractory pneumonia, showing no clinical or radiological response to macrolides, and can progress to severe and complicated pneumonia. Refractory MPP is characterized by an excessive immune response against the pathogen as well as direct injury caused by an increasing bacterial load. A change of antibiotics is recommended to reduce the bacterial load. Tetracyclines or quinolones can be alternatives for treating MRMP. Otherwise, corticosteroid or intravenous immunoglobulin can be added to the treatment regimen as immunomodulators to down-regulate an excessive host immune reaction and alleviate immune-mediated pulmonary injury. However, the exact starting time point, dose, or duration of immunomodulators has not been established. This review focuses on the mechanism of resistance acquisition and treatment options for MRMP pneumonia.

Propranolol as a First-line Treatment for Pediatric Hemangioma: Outcome of a Single Institution Over One Year / 임상소아혈액종양

BACKGROUND: Propranolol, a beta-blocker and well known anti-hypertensive medication, has been used as the first-line therapy for pediatric hemangioma since 2010. The objective of this study is to analyze the efficacy and safety of propranolol when used to treat pediatric hemangioma patients for one year or longer in a single institution.METHODS: A retrospective chart review analysis was done of 65 pediatric hemangioma patients treated with oral propranolol as the first-line therapy from 2010 to 2016. The patients were examined regularly at an interval of 1 to 2 months for changes in hemangioma size, growth and development, and occurrence of acute side effects of propranolol such as hypotension, hypoglycemia and bronchial constriction.RESULTS: Twenty patients were treated with propranolol for a year or longer and their median age was 202 days (range, 36 to 4,284 days) and mean duration of treatment was 22.5 months (range, 12 to 49 months). At 12 months of treatment, the average percentage of size decrement was 40.5%. When the weight and height percentile were compared between at diagnosis and 12 months post-treatment, all 20 patients showed normal growth curve and development. Patients did not show any acute side effects of propranolol during 12 months of treatment. One patient experienced hypoglycemia induced seizure, but this event was subsequently diagnosed as ketotic hypoglycemia induced from prolonged fasting.CONCLUSION: Propranolol was effective and well tolerated in children with hemangioma when used for one year or longer.

A Case of Myosin-heavy-chain-9 (MYH9) Gene Mutation Confirmed May-Hegglin Anomaly: 11-year Follow-up / 임상소아혈액종양

May-Hegglin anomaly (MHA) is a myosin-heavy-chain-9 (MYH9)-related disorder characterized by thrombocytopenia with giant platelets and inclusion bodies in leukocytes. MHA does not require treatment, but it may be misdiagnosed as immune thrombocytopenic purpura (ITP) and inappropriately managed. Reported herein is a case of a 12 year old female patient diagnosed as MHA with laboratory findings of severe thrombocytopenia and giant platelets in peripheral blood morphology, and followed up until 23 years of age. The patient had been diagnosed with ITP and treated with intravenous gamma-globulin therapy at another hospital, and showed no improvements in platelet count. She was then referred to our hospital for further diagnostic workup and followed up for 11 years, showing platelet count of 6,000-20,000/µL and prolonged platelet function test. She was occasionally treated with iron therapy due to iron-deficiency anemia. In 2014, we conducted a DNA analysis that revealed c.4339G>T(p.Asp1447Tyr), a known mutation of MYH9 gene.