Background: Although patients with malignant melanoma in situ (MIS) have a high survival rate, a risk of recurrence or upstaging remains. Thus, a comprehensive understanding of its prognosis is essential for optimal patient management. Objective: To investigate the clinical characteristics and survival outcomes of Korean patients with MIS. Methods: We retrospectively analyzed the medical records and photographs of patients with MIS treated at a single tertiary center between 2008 and 2021. Clinical features, including diagnosis, treatment, recurrence, and mortality, were examined. Results: A total of 156 patients with MIS were included, with a mean age of 59.3 years. The most common subtype was acral lentiginous melanoma (80.8%). Delayed diagnosis was associated with subungual MIS (SUMis; p ＜0.05). Among the subtypes other than SUMis, 77.3% met three or more of the ABCD criteria for melanoma.Hutchinson’s sign was observed in 67.3% of cases of SUMis. Ulceration was present in only two cases (1.3%).Recurrence occurred in nine patients (5.8%), with four (2.6%) experiencing relapse after 5 years. Upstaging was observed in two patients (1.3%) due to intralymphatic or regional nodal metastasis occurring at 19 and 10 months post-treatment. The 5-year and 10-year melanoma-specific/overall survival rates were 100.0/96.9% and 100.0/89.0%, respectively. Conclusion Although the survival rates of patients with MIS are high, long-term and close follow-up after treatment is essential because of the possibility of late recurrence and rare instances of intralymphatic or regional nodal metastasis. Additionally, the presence of clinical ulceration is highly suggestive of invasive melanoma.

Background: Biologics effectively improve psoriatic skin lesions, but their impact on itch relief remains unclear. Objective: To evaluate itch improvement in severe psoriasis patients treated with ustekinumab or guselkumab. Methods: This retrospective study analyzed patients with severe psoriasis who completed initial efficacy evaluations after treatment with either biologic. Itch severity was assessed using numerical rating scale (NRS), visual analog scale, and verbal rating scale. NRS improvement was evaluated after three injections. Results: Among 108 patients (74 on ustekinumab, 34 on guselkumab), 77 (71.3%) had moderate-to-severe itch (NRS ≥4) at baseline. Of these, 63 (81.8%) achieved an NRS improvement of ≥4 points. Ustekinumab showed greater itch relief compared to guselkumab in NRS (p=0.033). On the other hand, guselkumab showed more reduction for psoriatic skin lesions than ustekinumab in the Psoriasis Area and Severity Index (p=0.040). In the moderate-to-severe itch group, patients with large plaques experienced significantly greater improvement in NRS than those with small plaques (p=0.012). Conclusion While guselkumab is generally preferred for psoriatic skin lesions, ustekinumab may provide superior itch relief.

Atopic dermatitis (AD) is a chronic skin condition influenced by genetic, environmental, and immune factors, with notable ethnic variations in its prevalence and mechanisms. In Asian populations, distinct immunopathogenic features include the significant roles of helper (Th) 17 and Th22 cytokine pathways, differing from other ethnic groups. Key genetic variations related to immune regulation and skin barrier function are more prevalent in Asians. Microbiome studies reveal the role of Staphylococcus aureus in AD skin and emerging microbial species linked to microbiome dysbiosis and the gut-skin axis. Environmental factors like pollution and fine dust further exacerbate symptoms in Asia. This study consolidates findings to highlight the genetic, immunological, microbiome, and environmental factors contributing to AD’s unique characteristics in Asians. Tailored treatment approaches are essential for improving outcomes and management of AD in diverse populations.

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.