Background and Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep disorder characterized by recurrent upper airway obstruction, leading to disrupted sleep and various health complications. Positional OSA (POSA) refers to patients whose OSA severity is significantly influenced by body position, especially when lying supine. This study aimed to evaluate the polysomnographic characteristics of POSA and non-positional OSA (non-POSA) and to assess their clinical implications. Methods: This retrospective study included patients diagnosed with OSA who underwent type 1 polysomnography. Patients were categorized into POSA and non-POSA groups based on whether their apnea-hypopnea index (AHI) in the supine position was at least twice as high as that in the lateral position. We collected and analyzed clinical and polysomnographic parameters, including AHI, oxygen desaturation index, arousal index, nadir peripheral oxygen saturation (SpO2), and sleep position proportions. These were compared across different OSA severity levels—mild, moderate, and severe—to assess differences between the POSA and non-POSA groups. Results: In total, 500 patients with OSA were analyzed, of whom 63.4% were classified as having POSA. Patients with POSA exhibited milder disease severity than those without, with an average AHI of 23.3±15.3/h versus 43.9±27.9/h, respectively, and a higher nadir SpO2 of 82.8%±6.6% versus 77.1%±9.8%. POSA was more common in patients with mild OSA (76.5%) and moderate OSA (72.8%), while severe OSA cases were predominantly non-POSA (POSA was 47.4%). Moreover, patients with POSA spent significantly more sleep time in the lateral position (43.8%±22.7%) than non-POSA patients (27.2%±28.2%). Conclusion Patients with POSA generally exhibited milder disease and more favorable polysomnographic profiles than non-POSA patients. POSA is prevalent in mild-to-moderate OSA, and identifying it via polysomnography may inform tailored treatment strategies.

Background and Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep disorder characterized by recurrent upper airway obstruction, leading to disrupted sleep and various health complications. Positional OSA (POSA) refers to patients whose OSA severity is significantly influenced by body position, especially when lying supine. This study aimed to evaluate the polysomnographic characteristics of POSA and non-positional OSA (non-POSA) and to assess their clinical implications. Methods: This retrospective study included patients diagnosed with OSA who underwent type 1 polysomnography. Patients were categorized into POSA and non-POSA groups based on whether their apnea-hypopnea index (AHI) in the supine position was at least twice as high as that in the lateral position. We collected and analyzed clinical and polysomnographic parameters, including AHI, oxygen desaturation index, arousal index, nadir peripheral oxygen saturation (SpO2), and sleep position proportions. These were compared across different OSA severity levels—mild, moderate, and severe—to assess differences between the POSA and non-POSA groups. Results: In total, 500 patients with OSA were analyzed, of whom 63.4% were classified as having POSA. Patients with POSA exhibited milder disease severity than those without, with an average AHI of 23.3±15.3/h versus 43.9±27.9/h, respectively, and a higher nadir SpO2 of 82.8%±6.6% versus 77.1%±9.8%. POSA was more common in patients with mild OSA (76.5%) and moderate OSA (72.8%), while severe OSA cases were predominantly non-POSA (POSA was 47.4%). Moreover, patients with POSA spent significantly more sleep time in the lateral position (43.8%±22.7%) than non-POSA patients (27.2%±28.2%). Conclusion Patients with POSA generally exhibited milder disease and more favorable polysomnographic profiles than non-POSA patients. POSA is prevalent in mild-to-moderate OSA, and identifying it via polysomnography may inform tailored treatment strategies.

Background and Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep disorder characterized by recurrent upper airway obstruction, leading to disrupted sleep and various health complications. Positional OSA (POSA) refers to patients whose OSA severity is significantly influenced by body position, especially when lying supine. This study aimed to evaluate the polysomnographic characteristics of POSA and non-positional OSA (non-POSA) and to assess their clinical implications. Methods: This retrospective study included patients diagnosed with OSA who underwent type 1 polysomnography. Patients were categorized into POSA and non-POSA groups based on whether their apnea-hypopnea index (AHI) in the supine position was at least twice as high as that in the lateral position. We collected and analyzed clinical and polysomnographic parameters, including AHI, oxygen desaturation index, arousal index, nadir peripheral oxygen saturation (SpO2), and sleep position proportions. These were compared across different OSA severity levels—mild, moderate, and severe—to assess differences between the POSA and non-POSA groups. Results: In total, 500 patients with OSA were analyzed, of whom 63.4% were classified as having POSA. Patients with POSA exhibited milder disease severity than those without, with an average AHI of 23.3±15.3/h versus 43.9±27.9/h, respectively, and a higher nadir SpO2 of 82.8%±6.6% versus 77.1%±9.8%. POSA was more common in patients with mild OSA (76.5%) and moderate OSA (72.8%), while severe OSA cases were predominantly non-POSA (POSA was 47.4%). Moreover, patients with POSA spent significantly more sleep time in the lateral position (43.8%±22.7%) than non-POSA patients (27.2%±28.2%). Conclusion Patients with POSA generally exhibited milder disease and more favorable polysomnographic profiles than non-POSA patients. POSA is prevalent in mild-to-moderate OSA, and identifying it via polysomnography may inform tailored treatment strategies.

Background: Atopic dermatitis (AD) patients usually wonder if their condition will worsen after vaccination or if they should continue with the treatment they are receiving. Considering that many patients treated with dupilumab had previously experienced severe AD symptoms and flares, the concerns are more understandable. Objective: This study aimed to investigate the safety of the coronavirus disease 2019 (COVID-19) vaccination in patients with AD treated with dupilumab. Methods: We enrolled 133 patients (101 dupilumab-treated and 32 systemic oral agentstreated as control group) with AD from six hospitals. Patients were asked about worsening pruritus and AD (5-point Likert scale) after vaccination. AD variables (eczema area and severity index [EASI], investigator’s global assessment [IGA], itch numerical rating scale [NRS], sleep NRS, and patient-oriented eczema measure [POEM]) were compared pre- and postvaccination. Adverse reactions to the COVID-19 vaccination were observed. Results: The incidence of adverse reactions to COVID-19 vaccines and worsening AD symptoms in dupilumab-treated patients were not significantly different compared with that in the control group. The itch NRS score increased significantly after vaccination (p<0.001).However, there were no statistically significant differences between the pre-and post-EASI, IGA, and POEM scores. Eight patients (7.9%) had worse EASI scores and required rescue therapy; however, most were easily managed with low-dose steroids or topical agents. None of the patients discontinued dupilumab treatment. Conclusion No serious adverse reactions were observed in patients with AD after COVID-19 vaccination. Exacerbation of pruritus and AD symptoms was observed but was mostly mild and transient.

PELVIS syndrome describes the constellation of perineal hemangioma, external genitalia malformations, lipomyelomeningocele, vesicorenal abnormalities, imperforate anus, and skin tag. A 2-month-old girl presented with infantile hemangioma on her perineum and genitalia with imperforate anus, rectovaginal fistula and perineal skin tag at birth. Under the impression of PELVIS syndrome, consequential spinal sonography was conducted and revealed an intrasacral meningocele without clinical neurologic deficit. The anorectal malformation was surgically corrected, she was taking oral propranolol for the cutaneous lesion, and she showed improvement and no complications.

Merkel cell carcinoma (MCC), a rare cutaneous neuroendocrine carcinoma, is most common in sun-exposed areas of aged individuals. Merkel cell polyomavirus (MCPyV) is one causative agent of MCC. Cases of MCC concurrent with other skin tumors, especially squamous cell carcinoma, are rarely reported. Immunohistochemical staining is performed using antibodies to the MCPyV large-T antigen (CM2B4) only in select cases. To date, no cases of MCPyV have been reported in Korea. Here we report a case of MCC concurrent with squamous cell carcinoma in an aged man and discuss the pathogenesis of the case through CM2B4 staining.

The hepatitis A virus (HAV) induces severe acute liver injury and is adapted to human and monkey cell lines but not other cells. In this study, the HAV was inoculated into porcine kidney (PK-15) cells to determine its infectivity in porcine cells. The growth pattern of the HAV in PK-15 cells was compared with its growth pattern in fetal rhesus kidney (FRhK-4) cells. The growth of HAV was less efficient in PK-15 cells. In conclusion, HAV replication was verified in PK-15 cells for the first time. Further investigations will be needed to identify the HAV-restrictive mechanisms in PK-15 cells.

Biliary hamartomas are tumor-like malformations of the liver. Biliary hamartomas are a type of fibrocystic disorder originating from ductal plate malformation and are typically considered benign, but with the risk of malignant transformation. In this case report, we present a rare occurrence of intrahepatic cholangiocarcinoma (ICC) that developed from biliary hamartomas, along with a literature review. A 76-year-old man with a diagnosis of biliary hamartomas had a history of recurrent cholangitis for 12 years, necessitating cholecystectomy, ERCP, and repeated antibiotic treatments. During his last episode, imaging studies revealed a hypervascular infiltrative mass in the right posterior liver segment. A liver biopsy confirmed adenocarcinoma and subsequent surgical pathology revealed ICC originating from biliary hamartomas. Chronic inflammation in the bile duct associated with biliary hamartomas may serve as a potential trigger for malignant transformation, as observed in this case. Therefore, close surveillance is essential for patients with biliary hamartomas presenting with infectious complications.