Background: Primary cutaneous CD30+ lymphoproliferative disorders (pcCD30-LPDs) are a diseases with various clinical and prognostic characteristics. Objective: Increasing our knowledge of the clinical characteristics of pcCD30-LPDs and identifying potential prognostic variables in an Asian population. Methods: Clinicopathological features and survival data of pcCD30-LPD cases obtained from 22 hospitals in South Korea were examined. Results: A total of 413 cases of pcCD30-LPDs (lymphomatoid papulosis [LYP], n=237; primary cutaneous anaplastic large cell lymphoma [C-ALCL], n=176) were included. Ninety percent of LYP patients and roughly 50% of C-ALCL patients presented with multiple skin lesions. Both LYP and C-ALCL affected the lower limbs most frequently. Multiplicity and advanced T stage of LYP lesions were associated with a chronic course longer than 6 months. Clinical morphology with patch lesions and elevated serum lactate dehydrogenase were significantly associated with LPDs during follow-up in LYP patients. Extracutaneous involvement of C-ALCL occurred in 13.2% of patients. Lesions larger than 5 cm and increased serum lactate dehydrogenase were associated with a poor prognosis in C-ALCL. The survival of patients with C-ALCL was unaffected by the anatomical locations of skin lesions or other pathological factors. Conclusion The multiplicity or size of skin lesions was associated with a chronic course of LYP and survival among patients with C-ALCL.

Background: To address the public’s fear of coronavirus disease 2019 (COVID-19), understanding the clinical features of the disease is essential. However, research on the clinical features of COVID-19, including illness duration and post-acute COVID-19, in Korean pediatric patients has been limited. Therefore, this study investigated the clinical features of COVID-19 based on the medical records of pediatric patients with a history of COVID-19 who visited a single center. Methods: In total, 311 patients were included in this study. The presence and duration of 19 symptoms were examined. Additionally, clinical features were investigated by dividing the patients into different age ranges. Patients aged 6 and above were further categorized according to the presence of asthma, while adolescent patients were divided into vaccinated and unvaccinated groups. Results: Fever and cough were the most common symptoms. The mean illness duration was 2–4 days. Only 3.5% of the patients were asymptomatic. Post-acute COVID-19 was observed in 13.2% of the patients. The incidence of most symptoms tended to increase with age. Post-acute COVID-19 was observed more frequently in patients with asthma than in those without asthma. Vaccinated patients experienced less fever, vomiting, and fatigue than unvaccinated patients. Conclusions Our data suggest that most patients had mild disease lasting less than a week, and the clinical course may differ depending on the presence of asthma. The findings also indicate that vaccination may alleviate the symptoms of COVID-19 in breakthrough infections.

Background: Psoriasis imposes a significant treatment burden on patients, particularly impacting well-being and quality of life (QoL). The psychosocial impact of psoriasis treatments remains unexplored in most patient populations. Objective: To assess the impact of adalimumab on health-related QoL (HRQoL) in Korean patients with psoriasis. Methods: This 24-week, multicenter, observational study, assessed HRQoL in Korean patients treated with adalimumab in a real-world setting. Patient-reported outcomes (PROs) including European Quality of Life-5 Dimension scale (EQ-5D), EQ-5D VAS, SF-36, and DLQI were evaluated at week 16 and 24, versus baseline. Patient satisfaction was assessed using TSQM. Results: Among 97 enrolled patients, 77 were assessed for treatment effectiveness. Most patients were male (52, 67.5%) and mean age was 45.4 years. Median baseline body surface area and Psoriasis Area and Severity Index (PASI) scores were 15.00 (range 4.00~80.00) and 12.40 (range 2.70~39.40), respectively. Statistically significant improvements in all PROs were observed between baseline and week 24. Mean EQ-5D score improved from 0.88 (standard deviation [SD], 0.14) at baseline to 0.91 (SD, 0.17) at week 24 (p=0.0067). The number of patients with changes in PASI 75, 90, or 100 from baseline to week 16 and 24 were 65 (84.4%), 17 (22.1%), and 1 (1.3%); and 64 (83.1%), 21 (27.3%), and 2 (2.6%), respectively. Overall treatment satisfaction was reported, including effectiveness and convenience. No unexpected safety findings were noted. Conclusion Adalimumab improved QoL and was well-tolerated in Korean patients with moderate to severe psoriasis, as demonstrated in a real-world setting. Clinical trial registration number (clinicaltrials.gov: NCT03099083).

Background: Guselkumab is a monoclonal antibody that selectively blocks the p19 subunit of interleukin-23. It has shown good efficacy and safety profile in several clinical trials of plaque psoriasis. However, studies on the efficacy of guselkumab in patients treated with other biologics are lacking. Objective: We aimed to investigate the efficacy and safety profile of guselkumab in patients with moderate-to-severe plaque psoriasis. We also compared the efficacy of guselkumab between biologic-naïve (Bio-Naïve) and biologicexperienced (Bio-Ex) patients. Methods: This multicenter, retrospective study included 72 patients treated with guselkumab. The patients’ clinical characteristics and psoriasis area and severity index (PASI) scores were recorded at each visit. The PASI90 and PASI100 responses and mean PASI scores were compared between the Bio-Naïve and Bio-Ex groups. Results: Fifty-five Bio-Naïve patients and 17 Bio-Ex patients were included in the study. At week 20, there were no significant differences in the PASI90 (64.2% vs. 53.8%) and PASI100 (28.3% vs. 15.4%) responses between the groups. However, at weeks 36 and 44, the PASI90 response (week 36: 89.2% vs. 36.4% and week 44: 97.8% vs. 63.6%) and the PASI100 response (week 36: 64.9% vs. 18.2% and week 44: 68.9% vs. 27.3%) were significantly higher in the Bio-Naïve group (p＜0.05). There were no differences in PASI90 and PASI100 responses between the groups in terms of other clinical characteristics and comorbidities at week 20. Conclusion The efficacy of guselkumab remained consistent among patients in whom other biologics had failed. However, the efficacy was slightly lower in the Bio-Ex group than in the Bio-Naïve group.

Purpose: We investigated young children who developed bronchiolitis obliterans (BO) without preceding severe lower respiratory tract infection (LRTI). Methods: Twenty patients referred for chronic respiratory symptoms and diagnosed with BO were enrolled and divided into 2 age groups: group 1 ( < 2 years, n = 12) and group 2 ( ≥ 2, < 6 years, n = 8). A diagnosis of BO was made based on clinical and radiologic findings: (1) persistent cough or abnormal breath sounds which were not responsive to any treatment for more than 6 weeks; and (2) mosaic perfusion on high-resolution computed tomography. None of the subjects had experienced LRTI since birth, and those who had any underlying problems were excluded. The clinical characteristics and disease course were examined retrospectively. Results: Mean age of the patients was 6.8 months and 3.4 years in group 1 and 2, respectively. All patients presented with chronic cough and the most common type of cough was mixed (wet and dry), 67% in group 1 and 50% in group 2. Persistent stridor was the major respiratory sign in group 1 (67%), but 63% of group 2 patients showed no abnormal breath sounds. Chest x-ray finding was nonspecific in 75% each of both groups. The respiratory symptoms and signs resolved rapidly in most patients treated with pulse corticosteroid therapy. Bronchial hyperresponsiveness and decreased forced expiratory volume in 1 second were observed in 3 of group 2 children at age 6, during the follow-up. Conclusion Our study shows that BO could develop without preceding severe LRTI. It also suggests that BO should be considered in the infants with persistent stridor accompanied by chronic cough.

Purpose: Mycoplasma pneumoniae pneumonia (MP) is a major cause of community-acquired pneumonia (CAP) in children and is associated with extrapulmonary manifestations (EPM). The incidence and risk factors for EPM in children are unknown. Methods: This was a retrospective study involving 65,243 pediatric patients with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Medical records were reviewed to collect information regarding the clinical characteristics, radiological results, and laboratory findings. Logistic regression with multivariate analysis was performed to evaluate the risk factors associated with EPM in MP. Results: The incidence of EPM was 23.9%, including elevation of liver enzymes (18.1%), mucocutaneous manifestations (4.4%), proteinuria (4.1%), cardiovascular and neurological manifestations (0.4%), hematologic manifestations (0.2%), and arthritis (0.2%). Statistical analysis showed that mucocutaneous manifestations significantly increased with elevated alanine aminotransferase (adjusted odds ratio [aOR], 3.623; 95% confidence interval [CI], 1.933-6.790) and atopic sensitization (aOR, 2.973; 95% CI, 1.615–5.475) and decreased with respiratory virus coinfection (aOR, 0.273; 95% CI, 0.084–0.887). Elevated liver enzymes were significantly associated with elevated lactate dehydrogenase (aOR, 3.055; 95% CI, 2.257–4.137), presence of pleural effusion (aOR, 2.635; 95% CI, 1.767–3.930), and proteinuria with respiratory virus coinfection (aOR, 2.245; 95% CI, 1.113–4.527). Conclusion Approximately 24% of pediatric patients with MP had various EPM. As the risk factors associated with each EPM were different, it is necessary to evaluate the various clinical aspects and findings of MP to predict and prepare for the occurrence of EPM.

Background: Biologics-experienced patients are more likely to show a lower response to biologics than that of biologic-naïve patients. However, no consensus on switching biologics exists. Objective: We aimed to investigate the switching patterns and efficacy of the switched biologics in patients with moderate-to-severe psoriasis in actual clinical practice. Methods: This multicenter retrospective study included 37 patients with a history of switching biologics. We analyzed the reasons for switching, the switching patterns, and psoriasis area and severity index (PASI) 75 response rates after switching biologics. We also analyzed the factors affecting the PASI75 response rate to the second biologic. Results: The reasons for switching baseline biologics were primary failure in five patients (13.5%), secondary failure in 28 patients (75.7%), and adverse events in four patients (10.8%). The second biologics prescribed mostly include interleukin (IL)-23 inhibitor in twenty-four patients (64.9%), IL-17 inhibitor in eight patients (21.6%), tumor necrosis factor-α inhibitor in three patients (8.1%), and IL-12/23 inhibitor in two patients (5.4%). A total of 46% of patients (17/37) switched biologics from IL-12/23 inhibitors to IL-23 inhibitors. The PASI75 response rates at the primary endpoint of the second and third biologics were 89.2% and 88.8%, respectively. Our study found that female sex and obesity were associated with the primary failure of the second biologic. Conclusion Secondary failure was the most common reason for switching baseline biologics. Korean dermatologists prefer different classes of biologics while switching. The PASI75 response rates at the primary endpoints of the second and third biologics were relatively satisfactory.

Background: Psoriasis is a chronic disease that can have accompanying comorbidities including arthritis, metabolic syndrome, and cardiovascular diseases. Patients with psoriasis tend to frequently visit medical institutions, and their economic burden for medical services is high. Objective: To investigate the economic burden of psoriasis in Korea. Methods: The Korean Society for Psoriasis conducted a multi-center field survey of the patients and analyzed the national insurance claim data. Also, we discussed the medical environment of psoriasis in Korea based on the results. Results: The economic burden of psoriasis patients is substantial and varied by the type of medical institute. Patients also paid the indirect and intangible medical costs. Biological agents, which is used in patients with severe psoriasis, led to an increase in the cost. Conclusion This is the first study to estimate the economic burden of psoriasis in Korea comprehensively. To improve the medical environment of psoriasis and alleviate the burden of patients, discussion on the more efficient health policy and medical insurance criteria for psoriasis would be needed.

Purpose: Survivors of preterm birth are at high risk of chronic pulmonary disease. We examined lung function in the school-age children born preterm and investigated the relationship between lung function and clinical parameters. Methods: Thirty children born preterm were enrolled and divided into 2 groups: 14 very preterm (< 32-week gestational age [GA]) and 16 moderate-to-late preterm (32- to 36-week GA). Pulmonary function tests (PFTs) were performed repeatedly during schoolage and PFT parameters were compared with age-matched controls. The relationship between PFT and clinical parameters was also studied. Results: PFT parameters in the very preterm group were persistently reduced compared with age-matched controls (P< 0.05). Half of the children had been diagnosed with asthma at the visit for the first PFT. Seventy-seven percent of patients in the very preterm group had bronchial hyperresposiveness. Birth weight, duration of oxygen therapy and mechanical ventilation in the neonatal intensive care unit, and body weight at age 1 were associated with forced expiratory volume in 1 second (FEV 1), forced vital capacity (FVC), or forced expiratory flow between 25% and 75% of expired vital capacity (FEF 25%–75%) z-scores. Multiple regression analysis revealed that body weight at age 1 was an independent predictor of FEV 1 and FVC z-scores, and duration of oxygen therapy was independently associated with FEF 25%–75% z-scores (P< 0.01 for all). Conclusion No catch-up in lung function was observed in school-age children born very preterm. Lower body weight at age 1 might be an independent risk factor for reduced FEV 1 and FVC, whereas long-term oxygen therapy might be associated with reduced FEF 25%–75%

Purpose: Cluster analysis on pediatric asthma identifying a cluster characterized by obesity, females, and puberty showed that obesity is an independent risk factor for severe asthma in this cluster. In the present study, we aimed to investigate the effect of overweight/obesity on lung function and asthma severity in prepubertal asthmatic children. Methods: One hundred fifty-five prepubertal children (aged 6–10) with asthma were enrolled and divided into 2 groups: the overweight/obese group (body mass index [BMI] ≥ 85th percentile, n = 44) and the normal BMI group ( < 85th percentile, n = 111). We reviewed their medical records and analyzed whether there were any differences in clinical features, lung function and degree of bronchial hyperresponsiveness (BHR) between the 2 groups. The clinical factors associated with asthma severity were also investigated. Results: There was no difference in clinical features between the 2 groups. Pulmonary function tests showed that only forced vital capacity in 1 second/forced vital capacity (FEV1/FVC) was significantly lower in the overweight/obese group than in the normal BMI group (P = 0.032). There was no difference in dysanapsis and BHR between the 2 groups. There were significantly more children with moderate-to-severe asthma in the overweight/obese group compared to the normal BMI group (P = 0.018). In multivariate logistic regression analysis, overweight/obesity has been identified as an independent risk factor of affecting asthma severity (odds ratio, 2.44; P = 0.018), in addition to the already known risk factor, FEV1. Conclusion Our study showed that overweight/obese prepubertal asthmatic children had lower FEV1/FVC than those with normal BMI. It also suggests that overweight/obesity may be an independent risk factor for severe asthma before puberty.