Acanthosis nigricans (AN) is characterized by velvety hyperpigmented plaques, usually observed in skin folds. The different types of the condition include obesity-associated, syndromic, drug-induced, malignancy-related, and other types of AN. AN, an FGFR3 gene mutation-related disease, is associated with varying degrees of skeletal disorders. FGFR3 gene mutations are known to cause excessive inhibition of chondrocyte growth and keratinocyte proliferation, which is responsible for AN development. To our knowledge, only a small number of cases of AN with hypochondroplasia due to FGFR3 gene mutation (p.Lys650Thr) have been described in the literature. However, there are no reports of genetically confirmed AN with hypochondroplasia in Korea. Physicians should consider syndromic AN when symptoms develop at an early age or when associated skeletal anomalies are present.

Although ERCP is a therapeutic endoscopic procedure in pacreatico-biliary diseases, its rare complications, including pancreatitis, duodenal perforation, and bleeding, can be fatal. An 87-year-old woman with a history of gallbladder cancer presented with jaundice and general weakness. Her skin color was yellowish and epigastric tenderness was confirmed on a physical examination. On abdomen CT, the gallbladder cancer directly invaded the duodenum, common bile duct, and liver parenchyma. Enlarged portocaval lymph nodes obstructed the extrahepatic bile duct. ERCP was performed for bile duct decompression. When shortening of endoscopy was achieved, the duodenal lateral wall was perforated because of the endoscopic tip pressure. After inserting endoscopic retrograde biliary drainage and endoscopic nasobiliary drainage, endoclips were placed evenly around the defect, and a detachable snare was tightened around the endoclips. Three days later, the duodenal wall was not sealed on the abdomen CT scan. Repeat endoscopy was achieved, and the endoscopic nasobiliary drainage, endoscopic retrograde biliary drainage, endoclips, and detachable snare were removed. From the distal margin of the perforation, band ligation was performed, and a detachable snare was applied. The patient's condition improved after the second procedure. A percutaneous biliary stent was inserted, and she was discharged. This case highlights the successful endoscopic management of ERCP-related duodenal perforation.

Background: Juvenile dermatomyositis (JDM) is a rare but common childhood idiopathic inflammatory myopathy. Proximal muscle weakness and pathognomonic skin rash, Gottron papules, and heliotrope rash are characteristic clinical features of JDM. However, clinical analysis of JDM has rarely been reported in the Korean dermatologic literature. Objective: This study aimed to investigate the clinical features and outcomes of JDM in Korea and previous studies. Methods: We retrospectively reviewed the medical records and clinical photographs of patients diagnosed with JDM at Pusan National University Hospital (Busan and Yangsan) for 17 years (2005∼2021). Results: We encountered 12 patients with JDM (male to female ratio=7:5) with a mean age of 7.2 years. The most common clinical features were Gottron papules (100%), followed by Gottron sign (83.3%), malar rash (58.3%), heliotrope rash (41.7%), shawl sign (16.7%), calcinosis cutis (8.3%), and ulcer (8.3%). In all cases, there was no concurrent interstitial lung disease or an underlying malignancy. Only 1 of 12 patients complained of proximal muscle weakness, and four patients showed an increase in muscle enzymes in the laboratory test. The skin lesions gradually improved after systemic steroid or topical treatment in all cases. No additional proximal muscle weakness was found during the follow-up. Conclusion Although proximal muscle weakness is a common symptom in JDM, clinically amyopathic JDM is commonly found in dermatologic clinics. Regardless of subtype, all patients responded well to treatment and rarely encountered recurrence.

Phlegmonous gastritis is a disease caused by a bacterial infection of the gastric wall. This condition is rare, but when it does occur, its prognosis appears to be poor. The underlying etiology is largely unknown, but an immunocompromised state is considered an important risk factor. An 85-year-old woman presented with a confused mentality, fever, epigastric pain, and melena. There was no history of alcohol drinking or smoking, nor of previous gastric surgery. On the other hand, there was a history of senile dementia and cognitive impairment. Initial contrast-enhanced abdominal CT revealed gastric wall edema at the antrum with mucosal hyper-enhancement and an abscess in the thickened antrum. Upper gastrointestinal endoscopy on the fourth hospital day showed dark-colored fluid retention in the stomach. The gastric mucosa was inflamed and friable, with several ulcerative lesions showing purulent discharge. A toothpick was found in the process of identifying the base of the ulcerative lesion and was removed. Eventually, phlegmonous gastritis due to the penetration of a toothpick was diagnosed. After endoscopic toothpick removal, the patient's symptoms improved dramatically. Serial endoscopy revealed improvement in the gastric mucosa. This case is an example of phlegmonous gastritis caused by a foreign substance in the gastric wall of a patient with senile dementia. During upper gastrointestinal endoscopy in this case, identification of the base of ulcerative lesion played a critical role in the diagnosis.