This study aimed to identify age-specific characteristics of respiratory viral infections. Hospitalized patients with confirmed viral respiratory infections were included in the sample. The patients were divided into the pediatric group (<19 years old) and the adult group (≥19 years old). The groups were then subdivided based on age: 0–6, 7–12, 13–18, 19–49, 50–64, and ≥65 years old. These groups were compared to evaluate the differences in the pattern of respiratory viral infections. Among a total of 4058 pediatric patients (mean age 3.0 ± 2.9 years, n = 1793 females), 2829 (48.9%) had mono-infections, while 1229 (51.1%) had co-infections. Co-infections were the most common in the 0–6-year-old group (31.6%). Among 1550 adult patients (mean age 70.2 ± 15.3 years, n = 710 females), 1307 (85.6%) had mono-infections and 243 (14.4%) had co-infections. Co-infections were most common in the ≥65-year-old group (16.8%). Viral infection and co-infection rates decreased with age in pediatric patients but increased with increasing age in adults. In pediatric patients, the rates of viral infections and co-infections were high; the rate of co-infections was higher in younger patients. In adult patients, the rates of viral infections and co-infections were lower than those in pediatric patients; the rate of co-infections was higher in older patients.

The fabella is a normal structure, but is occasionally reported to cause posterior knee pain. The aim of this study was to present fabella syndrome after high tibial osteotomy. A 55-year-old female patient was admitted to the hospital due to about 1 year and 8 months of left knee pain. Sclerosis was observed in the anterior margin of the fabella in the preoperative magnetic resonance (MR) T2 image, and reactive bone marrow was found and was considered to be due to degeneration of the distal femur. Degenerative change (Kellgren and Lawrence—KL grade 2) of the left knee was observed, along with cartilage delamination corresponding to International Cartilage Repair Society (ICRS) grade 4 in the patellofemoral joint. We present the first reported case of fabella syndrome in Korea, after high tibial osteotomy due to degenerative arthritis and varus deformity, rather than artificial joint surgery. We excised the fabella from the patient's knee. There was no evidence of recurrence during 5 months of postoperative follow-up. Posterolateral Corner including the fabella might have sustained increased tensile force causing symptoms due to compression of the fabella by the posterior joint of the posterior femoral condyle. We present the first reported case of fabella syndrome in Korea, after high tibial osteotomy due to degenerative arthritis and varus deformity, rather than artificial joint surgery. Collision syndrome caused by a fabella has previously been attributed to inconsistency of the joint surface due to excessive exercise and degenerative changes due to knee instability. We report this case since it appeared to involve collision syndrome due to mechanical change of an angular deformity.

Choi YJ, et al. Allergy Asthma Immunol Res. 2022 May;14(3):289-299. https://doi.org/10.4168/aair.2022.14.3.289

Asthma and atopic dermatitis (AD) are representative chronic diseases in childhood. This study aimed to investigate the impact of preterm birth on the incidence and severity of asthma and AD in children, as well as to identify neonatal risk factors for asthma and AD. We used health claims data recorded between 2007 and 2014 in the Korean National Health Insurance Service database. We recruited 2,224,476 infants born between 2007 and 2014 and divided them into three groups: 3518 of extremely preterm (EP) infants (< 28 weeks of gestational age (GA)), 82,579 of other preterm (OP) infants (28–36 weeks of GA), and 2,138,379 of full-term (FT) infants (> 37 weeks of GA). We defined asthma as > 3 episodes of clinical visits in a year before 6 years of age, early asthma as onset at < 2 years of age, and severe asthma as > 1 event of status asthmaticus or admission to a hospital via an emergency room. AD was defined as ≥ 3 diagnoses in a year before 6 years of age, early AD as onset at < 2 years of age, and severe AD as prescription of high-potency topical steroids or immunosuppressants. An association of preterm birth with asthma and AD was assessed using inverse probability of treatment-weighted multivariable Cox regression analysis. Cardiorespiratory conditions, such as respiratory distress syndrome, bronchopulmonary dysplasia, patent ductus arteriosus, and pulmonary hypertension, significantly increased the risk of asthma. Specifically, bronchopulmonary dysplasia emerged as a significant risk factor for both severe and early-onset asthma (odds ratio (OR) 1.36, 95% CI 1.21–1.37 for severe asthma; OR 1.55, 95% CI 1.30–1.85 for early asthma), while it was associated with a decreased risk of AD (OR 0.86, 95% CI 0.80–0.92). Neonatal sepsis, jaundice, and retinopathy of prematurity were also identified as significant risk factors for later asthma. A stepwise increase in the risk of asthma with an increasing degree of prematurity was observed, with the OP group showing an adjusted hazard ratio (aHR) of 1.24 (95% CI: 1.22–1.26) and the EP group showing an aHR of 1.51 (95% CI: 1.41–1.63). Conversely, preterm birth was inversely associated with the risk of AD, with aHRs of 0.73 (95% CI: 0.67–0.79) for the OP group and 0.88 (95% CI: 0.87–0.89) for the EP group. Conclusion Preterm children have a significantly higher risk of asthma and lower risk of AD, with cardiorespiratory conditions significantly increasing the risk of asthma. Thus, we highlight the need for targeted respiratory management strategies for this high-risk population. What is Known: •Asthma and atopic dermatitis are prevalent chronic diseases in childhood, reducing the quality of life of children. •Preterm birth was associated with an increased risk of asthma, but few large nationwide studies. •Research on the relationship between preterm birth and pediatric atopic dermatitis is controversial, with few large nationwide studies. What is New: • Preterm children, especially born before 28 weeks of gestational age, had a significantly higher risk of asthma and lower risk of atopic dermatitis. • Cardiorespiratory comorbidities such as RDS, BPD, PDA, and pulmonary hypertension in neonatal period are prominent risk factors for asthma. • Preterm children are vulnerable to both early-onset and severe asthma.

Choi YJ, et al. Allergy Asthma Immunol Res. 2023 Nov;15(6):825-836. https://doi.org/10.4168/aair.2023.15.6.825

We report a case of an 8-year-old Korean girl diagnosed with severe fever with thrombocytopenia syndrome with Q fever coinfection after playing with a dog and being bitten by a tick in a suburb in South Korea. The clinical findings and treatment were summarized. To the best of our knowledge, this case is the youngest patient reported to have been diagnosed with severe fever with thrombocytopenia syndrome and Q fever from South Korea.