While the incidence of nephrotic syndrome (NS) is decreasing in Korea, the morbidity of difficult-to-treat NS is significant. Efforts to minimize treatment toxicity showed that prolonged treatment after an initial treatment for 2-3 months with glucocorticosteroids was not effective in reducing frequent relapses. For steroid-dependent NS, rituximab, a monoclonal antibody against the CD20 antigen on B cells, was proven to...

Antithymocyte globulin (ATG) is used as an immunosuppressive treatment (IST) to deplete clonal suppressor T cells in patients with severe aplastic anemia (SAA). The depletion of suppressor T cells by ATG may affect the activation of B cells, which results in an increased risk for autoimmune conditions. A 12-year-old boy was diagnosed with idiopathic SAA. As he did not have...

Lethargy in newborns usually indicates central nervous system dysfunction, and many conditions such as cerebrovascular events, infections, and metabolic diseases should be considered in the differential diagnosis. Nonketotic hyperglycinemia is an autosomal recessive error of glycine metabolism, characterized by myoclonic jerks, hypotonia, hiccups, apnea, and progressive lethargy that may progress to encephalopathy or even death. Cerebral sinovenous thrombosis is a...

Severe aplastic anemia (SAA) is a life-threatening disorder for which allogeneic hematopoietic stem cell transplantation (HSCT) is the current available curative treatment. HSCT from matched sibling donors (MSDs) is the preferred therapy for children with acquired SAA. For patients who lack MSDs, immunosuppressive therapy (IST) is widely accepted as a first-line treatment before considering HCT from an unrelated donor (URD)....

Most guidelines for chronic urticaria (CU) in infants and children are based on limited pediatric evidence. Current evidence used to guide treatment in children is extrapolated from data focusing on older age groups. CU in children is a different and complex condition than that in adults. Furthermore, there is little published information regarding urticaria in Korean children. The aim of...

Kawasaki disease (KD) is an acute systemic vasculitis that predominantly affects children, and can result in coronary artery lesions (CAL). A patient with KD who is resistant to treatment with intravenous immunoglobulin (IVIG) has a higher risk of developing CAL. Incomplete KD has increased in prevalence in recent years, and is another risk factor for the development of CAL. Although...

In patients with a language developmental delay, it is necessary to make a differential diagnosis for autism spectrum disorders (ASDs), specific language impairment, and mental retardation. It is important that pediatricians recognize the signs and symptoms of ASDs, as many patients with language developmental delays are ultimately diagnosed with ASDs. Pediatricians play an important role in the early recognition of...

3-methylcrotonyl-coenzyme A carboxylase (3MCC) deficiency is an autosomal recessive disorder in which leucine catabolism is hampered, leading to increased urinary excretion of 3-methylcrotonylglycine. In addition, 3-hydroxyisovalerylcarnitine levels increase in the blood, and the elevated levels form the basis of neonatal screening. 3MCC deficiency symptoms are variable, ranging from neonatal onset with severe neurological abnormality to a normal, asymptomatic phenotype. Although...

Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS), a very rare disease that is caused by the presence of antifactor II antibodies, is usually counterbalanced by the prothrombotic effect of lupus anticoagulant (LAC). Patients with LAHPS are treated using fresh frozen plasma, steroids, immunosuppressive agents, and immunoglobulins for managing the disease and controlling hemorrhages. Notably, steroids are the important treatment for treating hypoprothrombinemia and...

Respiratory distress syndrome (RDS) among preterm infants is typically due to a quantitative deficiency of pulmonary surfactant. Aside from the degree of prematurity, diverse environmental and genetic factors can affect the development of RDS. The variance of the risk of RDS in various races/ethnicities or monozygotic/dizygotic twins has suggested genetic influences on this disorder. So far, several specific mutations in...

Toxic epidermal necrolysis is an unpredictable and severe adverse drug reaction. In toxic epidermal necrolysis, epidermal damage appears to result from keratinocyte apoptosis. This condition is triggered by many factors, principally drugs such as antiepileptic medications, antibiotics (particularly sulfonamide), nonsteroidal anti-inflammatory drugs, allopurinol, and nevirapine. Lamotrigine has been reported potentially cause serious cutaneous reactions, and concomitant use of valproic acid...

The use of glucocorticoids (GCs) in the perinatal period is suspected of being associated with adverse effects on long-term neurodevelopmental outcomes for preterm infants. Repeated administration of antenatal GCs to mothers at risk of preterm birth may adversely affect fetal growth and head circumference. Fetal exposure to excess GCs during critical periods of brain development may profoundly modify the limbic...

Hemolytic uremic syndrome (HUS) is one of the most common causes of acute renal failure in childhood and is primarily diagnosed in up to 4.5% of children who undergo chronic renal replacement therapy. Escherichia coli serotype O157:H7 is the predominant bacterial strain identified in patients with HUS; more than 100 types of Shiga toxin-producing enterohemorrhagic E. coli (EHEC) subtypes have...

Griscelli syndrome type 2 (GS2) is a rare autosomal recessive disease caused by mutations in the RAB27A gene. It is characterized by cutaneous hypopigmentation, immunodeficiency, and hemophagocytic lymphohistiocytosis. We describe 2 brothers who had GS2 with clinically diverse manifestations. The elder brother presented with a purely neurological picture, whereas the younger one presented with fever, pancytopenia, hepatosplenomegaly, and erythema nodosum....

Channelopathies are a heterogeneous group of disorders resulting from the dysfunction of ion channels located in the membranes of all cells and many cellular organelles. These include diseases of the nervous system (e.g., generalized epilepsy with febrile seizures plus, familial hemiplegic migraine, episodic ataxia, and hyperkalemic and hypokalemic periodic paralysis), the cardiovascular system (e.g., long QT syndrome, short QT syndrome,...

Timely diagnosis of hyponatremia is important for preventing potential morbidity and mortality as it is often an indicator of underlying disease. The most common cause of eurvolemic hyponatremia is the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Recent studies have demonstrated that proinflammatory cytokines such as interleukin (IL) 1β and IL-6 are involved in the development of hyponatremia, a condition...

Here we present the case of an 11-year-old female patient diagnosed with Caroli syndrome, who had refractory esophageal varices. The patient had a history of recurrent bleeding from esophageal varices, which was treated with endoscopic variceal ligation thrice over a period of 2 years. However, the bleeding was not controlled. When the patient finally visited the Emergency Department, the hemoglobin...

Pyogenic liver abscess (PLA) is rare in healthy children. We report a case of PLA in an immunocompetent 12-year-old boy. Percutaneous catheter drainage was performed for the abscess. In addition, parenteral antibiotics were administered for 3 weeks. Klebsiella pneumoniae was detected in the culture of blood and drained fluid. Here, we present this case and a brief review of the...

Cystic fibrosis (CF) is a genetic disease with autosomal recessive inheritance and is common in Caucasian people. The prevalence of this disease is between 1/2,000 and 1/3,500 live births, and the incidence varies between populations. Although the CF transmembrane conductance regulator gene is expressed in the kidneys, renal involvement is rare. With advances in the treatment of CF, life expectancy...

A complex interplay between genetic and environmental factors partially contributes to the development of allergic diseases by affecting development during prenatal and early life. To explain the dramatic increase in the prevalence of allergic diseases, the hygiene hypothesis proposed that early exposure to infection prevented allergic diseases. The hygiene hypothesis has changed to the microbial hypothesis, in which exposure to...