Background: Several cases of pediatric acute hepatitis of unknown etiology related to adenoviral infections have been reported in Europe since January 2022. The aim of this study was to compare the incidence, severity, possible etiology, and prognosis of the disease with those in the past in Korea. Methods: The surveillance group collected data between May and November 2022 using a surveillance system. Acute hepatitis of unknown etiology was defined in patients aged < 16 years with a serum transaminase level > 500 IU/L, not due to hepatitis A-E or other underlying causes. For comparison, data from 18 university hospitals were retrospectively collected as a control group between January 2021 and April 2022. Results: We enrolled 270 patients (mean age, 5 years). The most common symptom was fever. However, the incidence was similar between 2021 and 2022. Liver function test results, number of patients with acute liver failure (ALF), liver transplantation (LT), death, and adenovirus detection rates did not differ between the two groups. None of the adenoviruspositive patients in either group experienced ALF, LT, or death. In the surveillance group, adenovirus-associated virus-2 was detected in four patients, one of whom underwent LT. Patients with an unknown etiology showed significantly higher bilirubin levels, a lower platelet count, and a higher LT rate than patients with a possible etiology. Conclusion The incidence of pediatric acute hepatitis of unknown etiology and adenovirus detection rate have not increased in Korea.

Pyoderma gangrenosum (PG) is a rare, non-infectious, neutrophilic dermatosis characterized by painful ulcers with indistinct borders and peripheral erythema. The diagnosis of PG requires the exclusion of other causes of similar appearing skin manifestations, including vasculitis and infections. The pathogenesis of PG is not clear; however, dysregulation of the immune system has been suggested in previous studies. More than half of the PG patients have underlying diseases; the most common being inflammatory bowel disease (IBD). The progression of PG in IBD patients is seen after the onset of IBD, usually during its exacerbation. On the other hand, PG may follow a course independent of the intestinal disease. We present a case of an 18-year-old young male with PG that presented before being diagnosed with ulcerative colitis as an associated condition. He had a painful ulcerative lesion on his right shin with no previous gastrointestinal symptoms. This case suggests that investigating for underlying disorders is essential in PG patients despite the lack of symptoms other than the skin lesions.

PURPOSE: To evaluate the prognostic value of 18F-fluorodeoxyglucose positron-emission tomography (FDG PET) with computed tomography (CT) before and during radiotherapy (RT) in patients with head and neck cancer. METHODS: Twenty patients with primary head and neck squamous cell carcinoma were enrolled in this study, of whom 6 had oropharyngeal cancer, 10 had hypopharyngeal cancer, and 4 had laryngeal cancer. Fifteen patients received concurrent cisplatin and 2 received concurrent cetuximab chemotherapy. FDG PET/CT was performed before RT and in the 4th week of RT. The parameters of maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of the primary tumor were measured, and the prognostic significance of each was analyzed with the Cox proportional hazards model. RESULTS: Higher TLG (>19.0) on FDG PET/CT during RT was a poor prognostic factor for overall survival (OS) (p = 0.001) and progression-free survival (PFS) (p = 0.007). In the multivariate analysis, TLG during RT as a continuous variable was significantly associated with OS and PFS rate (p = 0.023 and p = 0.016, respectively). Tumor response worse than partial remission at 1 month after RT was another independent prognostic factor for PFS (p = 0.024). CONCLUSIONS: Higher TLG of the primary tumor on FDG PET/CT during RT was a poor prognostic factor for OS and PFS in patients with head and neck cancer.
Carcinoma, Squamous Cell ; Cetuximab ; Cisplatin ; Disease-Free Survival ; Drug Therapy ; Glycolysis ; Head and Neck Neoplasms ; Head ; Humans ; Hypopharyngeal Neoplasms ; Laryngeal Neoplasms ; Multivariate Analysis ; Neck ; Oropharyngeal Neoplasms ; Positron-Emission Tomography ; Positron-Emission Tomography and Computed Tomography ; Proportional Hazards Models ; Radiotherapy ; Tumor Burden