Purpose: This study aimed to evaluate the effect of prophylactic abdominal drainage (AD) in laparoscopic hemicolectomy, focusing on assessing postoperative pain outcomes. Methods: Patients were categorized into two groups: those with and without AD (AD group vs.no-AD group). A numerical rating scale (NRS) was used to assess postoperative pain on each postoperative day (POD). Further, the inverse probability of treatment weighting (IPTW) method was used to reduce intergroup bias. Results: In total, 204 patients who underwent laparoscopic hemicolectomies by a single surgeon between June 2013 and September 2022 at a single institution were retrospectively reviewed. After adjusting for IPTW, NRS scores on POD 2 were significantly lower in the no-AD group (3.2 ± 0.8 vs. 3.4 ± 0.8, p = 0.043). Further examination of postoperative outcomes showed no statistically significant differences in complications between the AD (17.3%) and no-AD (12.4%) groups (p = 0.170). The postoperative length of hospital stay was 7.3 ± 2.8 days in the AD group and 6.9 ± 3.0 days in the no-AD group, with no significant difference (p = 0.298). Time to first flatus was 3.0 ± 0.9 days in the AD group and 2.7 ± 0.9 days in the no-AD group, with no significant difference (p = 0.078). Regarding readmission within 1 month, there were four cases each in the AD (2.3%) and no-AD (1.7%) groups, with no significant difference (p = 0.733). Conclusion Laparoscopic hemicolectomy without AD resulted in no significant differences in postoperative clinical outcomes, except for postoperative pain. This finding suggests that prophylactic AD may exacerbate postoperative pain.

Purpose: There is a lack of a report about the trajectories of allergen sensitization, although it is important to understand the change of allergen sensitization to manage allergic disease. This study aimed to analyze the change and trajectories of allergen sensitization in children with respiratory and allergic diseases. Methods: From 2006 to 2020, children with respiratory and allergic diseases or screened for allergic sensitization were evaluated. We visualized the alterations and the trajectories of allergen sensitization using stacked area graphs, box plots, and Sankey diagrams. Results: A total of 2,804 subjects were included, and allergic rhino-conjunctivitis was diagnosed in 1,931 children (68.9%). The mean age for the first test was 4.1 years, and that for the second test was 6.5 years. Children sensitized to class 1 food allergen before age 5 showed sensitizations more for other allergens and at a younger age after age 5 than children who were not. The atopic tendency continued once it had been obtained before the early school age in the persistence or the new development of sensitization. Conclusion Allergen sensitization has changed over time and has shown different patterns according to age. Its trajectory has taken a wide variety of courses in children with respiratory and allergic diseases until the early school age. These changes reflect the allergic diseases and socio-environmental characteristics of children and adolescents.

Purpose: Universal screening for Lynch syndrome (LS) refers to routine tumor testing for microsatellite instability (MSI) among all patients with colorectal cancer (CRC). Despite its widespread adoption, real-world data on the yield is lacking in Korean population. We studied the yield of adopting universal screening for LS in comparison with pedigree-based screening in a tertiary center. Materials and Methods: CRC patients from 2007-2018 were reviewed. Family histories were obtained and were evaluated for hereditary nonpolyposis colorectal cancer (HNPCC) using Amsterdam II criteria. Tumor testing for MSI began in 2007 and genetic testing was offered using all available clinicopathologic data. Yield of genetic testing for LS was compared for each approach and step. Results: Of the 5,520 patients, tumor testing was performed in 4,701 patients (85.2%) and family histories were obtained from 4,241 patients (76.8%). Hereditary CRC (LS or HNPCC) was present in 69 patients (1.3%). MSI-high was present in 6.9%, and 25 patients had confirmed LS. Genetic testing was performed in 41.2% (47/114) of MSI-high patients, out of which 40.4% (19/47) were diagnosed with LS. There were six additional LS patients found outside of tumor testing. For pedigree-based screening, Amsterdam II criteria diagnosed 55 patients with HNPCC. Fifteen of these patients underwent genetic testing, and 11 (73.3%) were diagnosed with LS. Two patients without prior family history were diagnosed with LS and relied solely on tumor testing results. Conclusion Despite widespread adoption of routine tumor testing for MSI, this is not a fail-safe approach to screen all LS patients. Obtaining a thorough family history in combination with universal screening provides a more comprehensive ‘universal’ screening method for LS.

Background: Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing. Methods: We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples. Results: Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing. Conclusions The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk.

Background: Although particulate matter likely provokes inflammatory reactions in those with chronic skin disorders like atopic dermatitis, no study has examined the relationship between particulate matter and psoriasis exacerbation. Objective: This study evaluated possible associations between particulate matter and hospital visits for psoriasis patients in 7 major cities in South Korea. Methods: We investigated the relationship between psoriasis and particulate matter. To do this, we used psoriasis patient data from the Korean National Health Insurance Service database. In addition, PM 10 and PM 2.5 concentration data spanning a 3-year time frame were obtained from the Korea Environment Corporation. Results: A pattern analysis generated by the sample cross-correlation function and time series regression showed a correlation between particulate matter concentration and the number of hospital visits by psoriasis patients. However, the prewhitening method, which minimizes the effects of other variables besides particulate matter, revealed no correlation between the two. Conclusion This study suggests that particulate matter has no impact on hospital visit frequency among psoriasis patients in South Korean urban areas.

Background/Aims: Membranous nephropathy (MN) is a major cause of nephrotic syndrome in adults. This study aimed to evaluate the effect of rituximab (RTX) in patients with idiopathic MN (iMN) who have a high risk of progression. Methods: We retrospectively analyzed data of 13 patients with iMN, who received RTX treatments from January 2014 to July 2020. RTX was indicated in patients with iMN with severe proteinuria and decreasing estimated glomerular filtration rate (eGFR) in the previous 6 months despite other immunosuppressive therapies. Results: The patients were predominantly males (n = 11) and with a mean age of 55.3 years; median eGFR, 37.0 mL/min/1.73 m2 (interquartile range [IQR], 26.3 to 66.5); serum albumin level, 2.6 g/dL (IQR, 1.9 to 3.1); and spot urine protein-to-creatinine ratio at baseline, 6.6 g/g (IQR, 5.7 to 12.9). In a median follow-up of 22 months, eight patients (61.5%) achieved complete or partial remission. In responder group (n = 8), median eGFR increased from 31.5 to 61.5 mL/min/1.73 m2 (p = 0.049) and serum albumin level increased from 2.3 to 4.2 g/dL (p = 0.017) from RTX initiation to last follow-up. Antiphospholipase A2 receptor antibody (anti-PLA2R-Ab) was positive in six among seven tested patients, which markedly decreased in the responder group. There were no adverse events after RTX. Conclusions This study suggests that RTX is a safe and effective treatment option for patients with iMN who have a high risk of progression. Individualized therapy based on anti-PLA2R-Ab titer would be needed for better outcomes.

Nevus comedonicus is a very rare skin disorder characterized by the presence of comedo-like dilated pores with keratinous plugs, rarely resulting in painful recurrent inflammatory nodules or cysts. It presents as localized or extensive form. It displays unilaterally or bilaterally segmental distribution. Histopathologically, it is characterized by keratin-filled epidermal invagination with bulbous proliferation of keratinocytes. The condition may be caused by fibroblast growth factor receptor 2 mutation. Although it may be controlled by a variety of therapeutic modalities, it is difficult to achieve complete resolution. We report a case of extensive nevus comedonicus with inflammatory nodules and cysts controlled with adalimumab.

Nevus comedonicus is a very rare skin disorder characterized by the presence of comedo-like dilated pores with keratinous plugs, rarely resulting in painful recurrent inflammatory nodules or cysts. It presents as localized or extensive form. It displays unilaterally or bilaterally segmental distribution. Histopathologically, it is characterized by keratin-filled epidermal invagination with bulbous proliferation of keratinocytes. The condition may be caused by fibroblast growth factor receptor 2 mutation. Although it may be controlled by a variety of therapeutic modalities, it is difficult to achieve complete resolution. We report a case of extensive nevus comedonicus with inflammatory nodules and cysts controlled with adalimumab.

Background: Cutaneous malignant melanoma (CMM) develops mainly in the elderly, although it is often seen in young patients and in clinical practice. However, there are few studies on the clinical features of young patients with CMM in Korea. Objective: To investigate the clinical characteristics of young Korean patients with CMM. Methods: We retrospectively reviewed the medical records of patients with CMM between January 2009 and June 2019 and compared the clinical features of CMM in patients aged 10∼39 and 50∼79 years. Results: Of the 341 patients with CMM, only 22 (6.5%) were between the age of 10∼39 and 250 (73.3%) were aged 50∼79. Acral lentiginous melanoma (ALM) was the most common clinical subtype in both groups (45.5% and 71.2%, respectively). Subungual melanoma was more common in age 10∼39 years (27.3% vs. 17.2%), whereas ALM except subungual melanoma was more common in age 50∼79 years (18.2% vs. 54.0%). Superficial spreading melanoma (31.8%) was also a significant subtype observed in age 10∼39 years (p＜0.001). Frequently involved locations in age group 10∼39 were fingers (27.3%) and trunk (22.7%), but feet (40.8%) were common in age group 50∼79 (p=0.009). There were no differences in mean Breslow thickness, lymph node metastases, or staging of CMM (p＞0.05). Conclusion Compared with elderly patients, CMM in patients aged 10∼39 showed differences in the location of the lesion and clinical subtype. Therefore, a misdiagnosis can be prevented when a young patient has suspected CMM on the finger or trunk.