Owing to advances in diagnostics and the increase in invasive procedures, and immunocompromised patients, cutaneous nontuberculous mycobacteria (NTM) infection is rising. NTM should be suspected in patients with persistent skin lesions refractory to treatment with a history of immunosuppression or skin injury. A 59-year-old woman presented with a 4-week history of multiple erythematous tender nodules on left arm. A year prior, multiple nodules appeared on left hand dorsum, followed by recurrent suppurative nodules in left arm. She has been taking methotrexate and leflunomide for 7 years due to rheumatoid arthritis (RA). Skin biopsy revealed granulomatous inflammation, and NTM polymerase chain reaction test was positive. Furthermore, she had cut her left finger with a knife 14 months ago. Based on these findings, cutaneous NTM infection was diagnosed. Herein, we report a case of cutaneous NTM infection in an immunosuppressed patient with RA, emphasizing differentiating subcutaneous nodules from rheumatoid nodules in RA.

Objectives: Interest in the association between particulate air pollution and appendicitis risk has been increasing in recent years, and previous studies have suggested a link between particulate matter ≤ 10 μm in diameter (PM10 ) and appendicitis. However, robust evidence is currently lacking. This study explored the association between short-term PM10 exposure and appendicitis using data from Ewha Womans University Mokdong Hospital, Seoul, Korea, between January 1, 2001 and December 31, 2018. Methods: We employed a time-stratified case-crossover design using data from 6,526 appendicitis patients taken from the hospital’s electronic medical records system. We analyzed the data using a conditional logistic regression model adjusted for daily mean temperature and relative humidity. The effect size of PM10 was estimated in terms of each 10 μm/m3 increase in PM10 concentration. Sex, season, and age group were analyzed as subgroups. Results: Appendicitis patients had been exposed to higher levels of PM10 concentrations 3 days (OR 1.045, 95% CI : 1.007–1.084) and 7 days (OR, 1.053; 95% CI, 1.005–1.103) before hospital admission. The case-crossover analysis stratified by sex, age, and season showed that the male sex, being aged under 10, and the cold season were associated with a significantly stronger association between appendicitis and PM10 concentrations. Conclusion Our study found that PM10 concentrations were associated with appendicitis in boys aged under 10. The cold season was also a risk factor. Further research with a larger sample size and with other pollutants is required to clarify the association between PM10 and appendicitis.

Background: The epidemiology of pathogenic bacteria varies according to the socioeconomic status and antimicrobial resistance status. However, longitudinal epidemiological studies to evaluate the changes in species distribution and antimicrobial susceptibility of pathogenic bacteria nationwide are lacking. We retrospectively investigated the nationwide trends in species distribution and antimicrobial susceptibility of pathogenic bacteria over the last 20 years in Korea. Methods: From 1997 to 2016, annual cumulative antimicrobial susceptibility and species distribution data were collected from 12 university hospitals in five provinces and four metropolitan cities in South Korea. Results: The prevalence of Staphylococcus aureus was the highest (13.1%) until 2012 but decreased to 10.3% in 2016, consistent with the decrease in oxacillin resistance from 76.1% in 2008 to 62.5% in 2016. While the cefotaxime resistance of Escherichia coli increased from 9.0% in 1997 to 34.2% in 2016, E. coli became the most common species since 2013, accounting for 14.5% of all isolates in 2016. Pseudomonas aeruginosa and Acinetobacter baumannii rose to third and fifth places in 2008 and 2010, respectively, while imipenem resistance increased from 13.9% to 30.8% and 0.7% to 73.5% during the study period, respectively.Streptococcus agalactiae became the most common pathogenic streptococcal species in 2016, as the prevalence of Streptococcus pneumoniae decreased since 2010. During the same period, pneumococcal penicillin susceptibility decreased to 79.0%, and levofloxacin susceptibility of S. agalactiae decreased to 77.1% in 2016. Conclusion The epidemiology of pathogenic bacteria has changed significantly over the past 20 years according to trends in antimicrobial resistance in Korea. Efforts to confine antimicrobial resistance would change the epidemiology of pathogenic bacteria and, consequently, the diagnosis and treatment of infectious diseases.

Background: Angiosarcoma (AS) and Kaposi sarcoma (KS) are rare malignant and borderline malignant vascular tumors that may first present to a dermatologist. There are few Korean studies that particularly focus on their survival due to low incidence. Objective: To investigate the survival and prognostic factors among patients with AS and KS, in addition to their clinical features. Methods: Between 2000∼2021, medical records of 26 AS and 26 KS patients at a single center were analyzed retrospectively. Additionally, we calculated the disease specific survival (DSS) and overall survival (OS) of two diseases. Results: The mean age of patients with AS was 72.9 years and 67.3 years for KS. The most common tumor location was the scalp in patients with AS (80.8%) and the foot (65.4%) in those with KS. In patients with AS, 1-year DSS and OS rates were 36.0% and 34.6%, respectively. Five-year DSS and OS rates were 24.0% and 20.2%, respectively. In patients with KS, the 1-year DSS and OS rates were 96.2% and 84.6%, respectively. The 5-year DSS and OS were 91.6% and 58.0%, respectively. Patients who were older or had larger lesions than average had decreased DSS and OS in AS. Among the patients with KS, immunosuppressed status, including human immunodeficiency virus infection, showed reduced OS. Conclusion Apart from confirming grave survival of AS and favorable survival of KS, patient’s age and size of lesion affect survival outcomes in patients with AS. Otherwise, immunosuppressed status affects survival outcomes in patients with KS.