Antibiotic Prescription in Patients With Coronavirus Disease 2019:Analysis of National Health Insurance System Data in the Republic of Korea

Background@#Although coronavirus disease 2019 (COVID-19) is a viral infection, antibiotics are often prescribed due to concerns about accompanying bacterial infection. Therefore, we aimed to analyze the number of patients with COVID-19 who received antibiotic prescriptions, as well as factors that influenced antibiotics prescription, using the National Health Insurance System database. @*Methods@#We retrospectively reviewed claims data for adults aged ≥ 19 years hospitalized for COVID-19 from December 1, 2019 to December 31, 2020. According to the National Institutes of Health guidelines for severity classification, we calculated the proportion of patients who received antibiotics and the number of days of therapy per 1,000 patient-days. Factors contributing to antibiotic use were determined using linear regression analysis. In addition, antibiotic prescription data for patients with influenza hospitalized from 2018 to 2021 were compared with those for patients with COVID-19, using an integrated database from Korea Disease Control and Prevention Agency-COVID19-National Health Insurance Service cohort (K-COV-N cohort), which was partially adjusted and obtained from October 2020 to December 2021. @*Results@#Of the 55,228 patients, 46.6% were males, 55.9% were aged ≥ 50 years, and most patients (88.7%) had no underlying diseases. The majority (84.3%; n = 46,576) were classified as having mild-to-moderate illness, with 11.2% (n = 6,168) and 4.5% (n = 2,484) having severe and critical illness, respectively. Antibiotics were prescribed to 27.3% (n = 15,081) of the total study population, and to 73.8%, 87.6%, and 17.9% of patients with severe, critical, and mild-to-moderate illness, respectively. Fluoroquinolones were the most commonly prescribed antibiotics (15.1%; n = 8,348), followed by third-generation cephalosporins (10.4%; n = 5,729) and beta-lactam/beta-lactamase inhibitors (6.9%; n = 3,822). Older age, COVID-19 severity, and underlying medical conditions contributed significantly to antibiotic prescription requirement. The antibiotic use rate was higher in the influenza group (57.1%) than in the total COVID-19 patient group (21.2%), and higher in severe-to-critical COVID-19 cases (66.6%) than in influenza cases. @*Conclusion@#Although most patients with COVID-19 had mild to moderate illness, more than a quarter were prescribed antibiotics. Judicious use of antibiotics is necessary for patients with COVID-19, considering the severity of disease and risk of bacterial co-infection.

A Retrospective National Study on Colonization Rate and Antimicrobial Susceptibility of Streptococcus agalactiae in Pregnant Korean Women, 2018–2020

Purpose@#The prevalence of Group B Streptococcus (GBS) colonization in pregnant Korean women is increasing; however, nationwide studies are lacking. Therefore, we aimed to analyze regional colonization rates and antimicrobial susceptibility for GBS in pregnant Korean women through a nationwide survey. @*Materials and Methods@#From January 2018 to December 2020, data from the Seoul Clinical Laboratories on vaginal swab cultures were retrospectively analyzed to detect maternal GBS carriers. Each swab specimen was inoculated onto a 5% blood agar plate and incubated at 35°C–37°C in a 5% CO 2 incubator for 24 h. GBS isolates were identified using a Microflex MALDI Biotyper. Antimicrobial susceptibility tests were performed using the Vitek 2 automated system. @*Results@#The overall nationwide GBS colonization rate in pregnant Korean women was found to be 10.6% (3578/33721). The maternal GBS colonization rates ranged from 10.5%–10.8% over the 3-year study period. The GBS colonization rates by province, in descending order, were as follows: Jeolla-do, 13.2%; Gangwon-do, 12.0%; Chungcheong-do, 11.8%; Gyeonggi-do, 11.3%; Seoul, 10.2%; and Gyeongsang-do, 9.6%. During the study period, the resistance rates against chloramphenicol, levofloxacin, clindamycin, erythromycin, and tetracycline were 2.6%–2.7%, 18.2%–19.6%, 33.4%–35.7%, 35.6%–36.8%, and 50.5%–53.3%, respectively. @*Conclusion@#In pregnant Korean women, GBS colonization rates were in the range of 9.6%–13.2%, with Gyeongsang-do being the lowest and Jeolla-do the highest. The resistance rate against clindamycin was high (33.4%–35.7%). GBS colonization rates during pregnancy should be studied nationwide according to the Centers for Disease Control and Prevention-recommended guidelines with periodic antimicrobial resistance monitoring.

Effectiveness of Regdanvimab at Preventing the Need for Oxygen Therapy in Patients with Mild-to-Moderate COVID-19: A Retrospective Cohort Study

Background@#Monoclonal antibodies are a treatment option for patients with mild-tomoderate coronavirus disease (COVID-19). We investigated the effectiveness of regdanvimab, an anti-severe acute respiratory syndrome coronavirus-2 monoclonal antibody approved in Korea, in the treatment of patients with mild-to-moderate COVID-19. @*Materials and Methods@#Medical records of patients who were admitted to a COVID-19 designated hospital during the study period of February 1 to June 31 and met the indications for administration of regdanvimab were reviewed to assess baseline characteristics and clinical outcomes such as supplemental oxygen requirements, mortality, and length of hospitalization. Multivariable logistic regression analysis was conducted to identify factors associated with requiring supplemental oxygen. Subgroup analysis was performed according to the presence of pneumonia confirmed on a chest X-ray. @*Results@#Three hundred ninety-eight COVID-19 patients were included in the study, and 65 (16.3%) of them were administered regdanvimab. The proportion of patients requiring supplemental oxygen was significantly lower in the regdanvimab group than in the control group (6.2% vs. 20.1%, P = 0.007). There was no significant difference in mortality (0% vs.1.5%, P >0.999) and the length of hospitalization (median: 10 days vs. 10 days, P = 0.267) between two groups. The multivariable analysis demonstrated that administration of regdanvimab was independently associated with lower oxygen supplement [odds ratio (OR): 0.20, 95% confidence interval (CI): 0.06 - 0.55, P = 0.004] after adjustment of potential risk factors related to supplemental oxygen including age, sex, chest X-ray abnormality, and underlying chronic kidney disease. Among the patients with pneumonia radiologically, administration of regdanvimab was also associated with lower risk of oxygen supplement (OR: 0.13, 95% CI: 0.02 - 0.46, P = 0.007). @*Conclusion@#Regdanvimab use was related to lower need for supplemental oxygen in patients with mild-to-moderate COVID-19 for the indications for administration of regdanvimab.

Recent Epidemiological Changes in Group B Streptococcus Among Pregnant Korean Women

Background@#Although group B Streptococcus (GBS) colonization rate among pregnant Korean women is lower than that among women from many Western countries, recent data show an upward trend. We investigated recent epidemiological changes in GBS among pregnant Korean women in terms of colonization rate, antimicrobial susceptibility, serotype, and resistance genotype. @*Methods@#Vaginal and anorectal swab specimens from 379 pregnant Korean women were cultured on Strep B Carrot Broth with GBS Detect (Hardy Diagnostics, USA), selective Todd-Hewitt broth (Becton Dickinson, USA), and Granada agar plate medium (Becton Dickinson). The antimicrobial susceptibility, serotypes, and macrolide-lincosamide-streptogramin B (MLS B) resistance genes of the GBS isolates were tested. @*Results@#The GBS colonization rate among pregnant Korean women was 19.8% (75/379).Colonization rates using Strep B Carrot Broth with GBS Detect, selective Todd-Hewitt broth, and Granada agar plate medium cultures were 19.5%, 19.3%, and 15.0%, respectively.Six pregnant women were colonized by non-beta-hemolytic GBS and were detected only in Strep B Carrot Broth with GBS Detect. Resistance rates of GBS to clindamycin, erythromycin, and tetracycline were 16.0%, 28.0%, and 42.7%, respectively. The most common GBS serotypes were V (22.7%), VIII (20.0%), and III (20.0%). The frequency of MLS B resistance genes erm(B) and erm(TR) were 63.6% and 36.4%, respectively. @*Conclusions@#The GBS colonization rate among pregnant Korean women has risen to levels observed in Western countries. To accurately evaluate GBS epidemiology among pregnant Korean women, periodic studies in multiple centers, including primary clinics, are necessary.

A Case of unexpected Fatal Hemoperitoneum in Non-severe Acute Pancreatitis / 고신대학교의과대학학술지

Acute pancreatitis (AP) severity is determined by associated organ failure (OF). However, enzymatic erosion of peripancreatic vessels can lead to life-threatening hemoperitoneum in clinically non-severe AP without OF. We herein report a case of unexpected hemoperitoneum which developed in a patient with clinically resolving AP without OF. A 36-year-old woman with alcohol use disorder presented with resolving epigastric pain and sustained abdominal distension of 2 weeks’ duration. Ranson’s score on admission was 1 and Computed tomography (CT) revealed non-necrotic AP with peripancreatic fluid collection. She showed sudden hypotension with an abrupt decrease in serum hemoglobin within 24 hours after admission. She was suspected to have an acute hemoperitoneum associated with venous bleeding from AP based on repeated CT. Venous bleeding from the splenic branch was ligated during surgery. The possibility of bleeding at the pancreatic bed should be considered even if the pancreatitis is not severe.

Prediction Model for Massive Transfusion in Placenta Previa during Cesarean Section

0.05). The area under the receiver operating characteristics curve (AUC) was 0.922 [95% confidence interval (CI) 0.89–0.95]. In external validation, the discrimination was good, with an AUC value of 0.833 (95% CI 0.70–0.92) for this model. Nomogram calibration plots indicated good agreement between the predicted and observed outcomes, exhibiting close approximation between the predicted and observed probability.CONCLUSION: We constructed a scoring model for predicting massive transfusion during cesarean section in women with placenta previa. This model may help in determining the need to prepare an appropriate amount of blood products and the optimal timing of blood transfusion.

Scheduled injection of ramosetron for prevention of nausea and vomiting following single-port access total laparoscopic hysterectomy: a prospective randomized study

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of scheduled ramosetron injections for controlling postoperative nausea and vomiting (PONV) after single-port access total laparoscopic hysterectomy (SPA-TLH). METHODS: Ninety patients who underwent SPA-TLH at the Korean National Health Insurance Service Ilsan Hospital between June 2013 and July 2014 were enrolled in this prospective, randomized, double-blinded, placebo-controlled study. The patients were divided into 2 groups as follows: the ramosetron group (0.3 mg intravenously [IV]; n=45) and the placebo group (normal saline IV; n=45). Both groups received their respective injections 12 and 24 hours post surgery. The incidence and severity of PONV (numerical rating scale, 0–10), and the use of rescue antiemetics post surgery were evaluated. RESULTS: Demographic and perioperative statistically significant differences were not observed between the 2 groups. The incidence of PONV in the ramosetron and placebo groups was 46.7% and 51.1%, respectively (P=0.51). We found significant differences in the severity of PONV between the 24- to 48-hour postoperative periods in both groups (ramosetron group, P=0.04 and placebo group, P=0.03). The use of rescue antiemetics was significantly lower in the ramosetron group than in the placebo group (P=0.02). CONCLUSION: After general anesthesia, scheduled injections of ramosetron 12 and 24 hours after SPA-TLH reduced the severity of PONV and the use of rescue antiemetics. Administration of ramosetron can be considered not only immediately after SPA-TLH but also during the first 24-hour recovery period. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT 02011659

Prevalence of Operation Room-Related Syncope and Presyncope among Medical Students / 의학교육논단

Attending the operation room is an essential part of surgical clerkships. Syncope or presyncopal attacks in the operation room may negatively affect students' learning and career development. This study set out to identify the prevalence of syncope and presyncopal attacks in the operation room during medical students' surgical clerkships. Data from 420 medical students (303 men and 117 women) in their 3rd year of clerkship were collected between 2014 and 2017. An anonymous questionnaire was distributed to assess the prevalence and degree of syncope and presyncopal symptoms. A total of 27% of the respondents had experienced syncope or presyncopal symptoms, 49.6% of the female students and 18.8% of the male students (p < 0.001). Fifty students (43.5%) had been attending as observers at the time of the syncopal attack, while 65 students (56.5%) had been participating as assistants. Thirty-four students (29.6%) had recently eaten at the time of the syncopal attack, while 81 students (70.4%) had not recently eaten. Prodromal symptoms included the urge to sit down (21.2%), sweating (19.3%), nausea (16.9%), a feeling of warmth (13.3%), darkened vision (12.6%), yawning (11.7%), palpitation (11.0%), ear fullness (10.2%), black spots in one's vision (7.6%), and hyperventilation (7.1%). This study showed the prevalence of syncope and presyncopal symptoms in the operation room during surgical clerkships. For students' safety and effective clerkship learning, thorough proactive education on syncopal attacks is required.

Comparison of volatile organic compounds between cigarette smoke condensate (CSC) and extract (CSE) samples

Cigarette smoke is a major risk factor for several diseases, including chronic obstructive pulmonary and cardiovascular diseases. The toxicity of the cigarette smoke can be determined in vitro. The cytotoxicity test of the cigarette smoke is commonly conducted using the cigarette smoke condensate (CSC) and cigarette smoke extract (CSE). The CSC and CSE methods are well known for sampling of the particles and water-soluble compounds in the cigarette smoke, respectively. In this study, the CSC and CSE were analyzed by using a gas chromatography-mass spectrometry (GC-MS) system equipped with a wax column for separation of the volatile organic compounds. The cytotoxic effect of the CSC and CSE were evaluated thoroughly by comparing the analytical results of the CSC and CSE samples. The total concentration of the volatile organic compounds detected in the CSC sample was similar to that in the CSE sample based on the peak area. Except for the dimethyl sulfoxide solvent, nicotine had the highest concentration in the CSC sample, while acetonitrile had the highest concentration in the CSE sample. The compositions were as follows: (1) CSC sample: 55.8% nicotine, 18.0% nicotyrine, 3.20% 1,2,3-propanetriol, triacetate, 1.28% ethyl chloride, 1.22% phenol, etc. and (2) CSE sample: 18.7% acetonitrile, 18.0% acetone, 12.5% 2-hydroxy-2-methyl-propanenitrile, 8.98% nicotine, 5.86% nicotyrine, etc. In this manner, to accurately examine the cytotoxicity of the cigarette smoke using CSC or CSE, the components and their concentrations in the CSC and CSE samples should be considered.

Comparison of volatile organic compounds between cigarette smoke condensate (CSC) and extract (CSE) samples

Cigarette smoke is a major risk factor for several diseases, including chronic obstructive pulmonary and cardiovascular diseases. The toxicity of the cigarette smoke can be determined in vitro. The cytotoxicity test of the cigarette smoke is commonly conducted using the cigarette smoke condensate (CSC) and cigarette smoke extract (CSE). The CSC and CSE methods are well known for sampling of the particles and water-soluble compounds in the cigarette smoke, respectively. In this study, the CSC and CSE were analyzed by using a gas chromatography-mass spectrometry (GC-MS) system equipped with a wax column for separation of the volatile organic compounds. The cytotoxic effect of the CSC and CSE were evaluated thoroughly by comparing the analytical results of the CSC and CSE samples. The total concentration of the volatile organic compounds detected in the CSC sample was similar to that in the CSE sample based on the peak area. Except for the dimethyl sulfoxide solvent, nicotine had the highest concentration in the CSC sample, while acetonitrile had the highest concentration in the CSE sample. The compositions were as follows: (1) CSC sample: 55.8% nicotine, 18.0% nicotyrine, 3.20% 1,2,3-propanetriol, triacetate, 1.28% ethyl chloride, 1.22% phenol, etc. and (2) CSE sample: 18.7% acetonitrile, 18.0% acetone, 12.5% 2-hydroxy-2-methyl-propanenitrile, 8.98% nicotine, 5.86% nicotyrine, etc. In this manner, to accurately examine the cytotoxicity of the cigarette smoke using CSC or CSE, the components and their concentrations in the CSC and CSE samples should be considered.

Systematic Analysis of the Anticancer Agent Taxol-Producing Capacity in Colletotrichum Species and Use of the Species for Taxol Production

Paclitaxel (taxol) has long been used as a potent anticancer agent for the treatment of many cancers. Ever since the fungal species Taxomyces andreanae was first shown to produce taxol in 1993, many endophytic fungal species have been recognized as taxol accumulators. In this study, we analyzed the taxol-producing capacity of different Colletotrichum spp. to determine the distribution of a taxol biosynthetic gene within this genus. Distribution of the taxadiene synthase (TS) gene, which cyclizes geranylgeranyl diphosphate to produce taxadiene, was analyzed in 12 Colletotrichum spp., of which 8 were found to contain the unique skeletal core structure of paclitaxel. However, distribution of the gene was not limited to closely related species. The production of taxol by Colletotrichum dematium, which causes pepper anthracnose, depended on the method in which the fungus was stored, with the highest production being in samples stored under mineral oil. Based on its distribution among Colletotrichum spp., the TS gene was either integrated into or deleted from the bacterial genome in a species-specific manner. In addition to their taxol-producing capacity, the simple genome structure and easy gene manipulation of these endophytic fungal species make them valuable resources for identifying genes in the taxol biosynthetic pathway.

Successful Hysterectomy and Therapeutic Hypothermia Following Cardiac Arrest due to Postpartum Hemorrhage / 대한구급학회지

Postpartum hemorrhage is a common cause of maternal mortality; its main cause is placenta accreta. Therapeutic hypothermia is a generally accepted means of improving clinical signs in postcardiopulmonary resuscitation patients. A 41-year-old pregnant woman underwent a cesarean section under general anesthesia at 37 weeks of gestation. After the cesarean section, the patient experienced massive postpartum bleeding, which led to cardiac arrest. Once spontaneous circulation returned, the patient underwent an emergency hysterectomy and was placed under therapeutic hypothermia management. The patient recovered without neurological complications.

Subacute progressive disseminated histoplasmosis in immunocompetent patient

No abstract available.

Successful Hysterectomy and Therapeutic Hypothermia Following Cardiac Arrest due to Postpartum Hemorrhage / 대한중환자의학회지

Postpartum hemorrhage is a common cause of maternal mortality; its main cause is placenta accreta. Therapeutic hypothermia is a generally accepted means of improving clinical signs in postcardiopulmonary resuscitation patients. A 41-year-old pregnant woman underwent a cesarean section under general anesthesia at 37 weeks of gestation. After the cesarean section, the patient experienced massive postpartum bleeding, which led to cardiac arrest. Once spontaneous circulation returned, the patient underwent an emergency hysterectomy and was placed under therapeutic hypothermia management. The patient recovered without neurological complications.

Successful Treatment of Relapsed Acquired Amegakaryocytic Thrombocytopenia with Repeat Cyclosporine / 대한내과학회지

Acquired amegakaryocytic thrombocytopenia (AAMT) is an unusual disease characterized by severe thrombocytopenia resulting from a marked decrease in bone marrow megakaryocytes. Various pathogenic mechanisms have been suggested, and several treatments have been tried, with varying outcomes. In some case reports, cyclosporine and anti-thymocyte globulin have had good clinical results in the treat of AAMT. There are few reports on the treatment of relapsed AAMT with cyclosporine. We report a patient with relapsed AAMT who was treated successfully with an additional course of cyclosporine. The initial remission was achieved with cyclosporine 4 years earlier and a second remission was induced by cyclosporine. Cyclosporine may be effective for relapsed AAMT that previously responded to cyclosporine.

Intermittent Claudication Caused by Popliteal Artery Compression of Popliteal Cyst

Peripheral arterial disease is caused by atherosclerosis in the arteries causing an insufficient blood flow to the muscles and tissues. Peripheral arterial disease in the lower limbs is the main cause of intermittent claudication. Less commonly, the etiology of intermittent claudication can be extrinsic to vascular structures such as arterial aneurysm, arterial dissection, embolism, popliteal entrapment syndrome, and adventitial cystic disease. A 69-year-old man was referred to Sanggye Paik Hospital because of intermittent claudication. He had a history of diabetes mellitus and dyslipidemia and he was current smoker. His right ankle brachial index is 0.74. Lower extremity artery computed tomography scan was performed and it revealed the right popliteal cyst compressing the right popliteal artery. We performed the arthroscopic cyst drainage and after the procedure, intermittent claudication resolved completely.

Cryptococcal Meningoencephalitis in a Systemic Lupus Erythematosus Patient without Immunosuppressants / 대한내과학회지

Cryptococcosis is an opportunistic infection that generally occurs in patients with cell-mediated immune dysfunction and involves the central nervous system. Infection is a major cause of morbidity and mortality in systemic lupus erythematosus (SLE) patients because of its innate immune dysfunction along with the administration of steroids and immunosuppressants. However, central nervous system cryptococcosis has rarely been reported in SLE patients. A timely diagnosis is critical because of its significant mortality and morbidity. Most cases of cryptococcal meningitis in SLE patients have been reported in those treated with steroids or immunosuppressants. We report on a SLE patient not on medication, who was diagnosed with cryptococcal meningoencephalitis.

Comparative evaluation of the mutagenicity and genotoxicity of smoke condensate derived from Korean cigarettes

OBJECTIVES: Cigarette smoking is associated with carcinogenesis owing to the mutagenic and genotoxic effects of cigarette smoke. The aim of this study was to evaluate the mutagenic and genotoxic effects of Korean cigarettes using in vitro assays. METHODS: We selected 2 types of cigarettes (TL and TW) as benchmark Korean cigarettes for this study, because they represent the greatest level of nicotine and tar contents among Korean cigarettes. Mutagenic potency was expressed as the number of revertants per μg of cigarette smoke condensate (CSC) total particulate matter whereas genotoxic potency was expressed as a concentration-dependent induction factor. The CSC was prepared by the International Organization for Standardization 3308 smoking method. CHO-K1 cells were used in vitro micronucleus (MNvit) and comet assays. Two strains of Salmonella typhimurium (Salmonella enterica subsp.enterica; TA98 and TA1537) were employed in Ames tests. RESULTS: All CSCs showed mutagenicity in the TA98 and TA1537 strains. In addition, DNA damage and micronuclei formation were observed in the comet and MNvit assays owing to CSC exposure. The CSC from the 3R4F Kentucky reference (3R4F) cigarette produced the most severe mutagenic and genotoxic potencies, followed by the CSC from the TL cigarette, whereas the CSC from the TW cigarette produced the least severe mutagenic and genotoxic potencies. CONCLUSIONS: The results of this study suggest that the mutagenic and genotoxic potencies of the TL and TW cigarettes were weaker than those of the 3R4F cigarette. Further study on standardized concepts of toxic equivalents for cigarettes needs to be conducted for more extensive use of in vitro tests.

Comparative evaluation of the mutagenicity and genotoxicity of smoke condensate derived from Korean cigarettes

OBJECTIVES: Cigarette smoking is associated with carcinogenesis owing to the mutagenic and genotoxic effects of cigarette smoke. The aim of this study was to evaluate the mutagenic and genotoxic effects of Korean cigarettes using in vitro assays. METHODS: We selected 2 types of cigarettes (TL and TW) as benchmark Korean cigarettes for this study, because they represent the greatest level of nicotine and tar contents among Korean cigarettes. Mutagenic potency was expressed as the number of revertants per μg of cigarette smoke condensate (CSC) total particulate matter whereas genotoxic potency was expressed as a concentration-dependent induction factor. The CSC was prepared by the International Organization for Standardization 3308 smoking method. CHO-K1 cells were used in vitro micronucleus (MNvit) and comet assays. Two strains of Salmonella typhimurium (Salmonella enterica subsp.enterica; TA98 and TA1537) were employed in Ames tests. RESULTS: All CSCs showed mutagenicity in the TA98 and TA1537 strains. In addition, DNA damage and micronuclei formation were observed in the comet and MNvit assays owing to CSC exposure. The CSC from the 3R4F Kentucky reference (3R4F) cigarette produced the most severe mutagenic and genotoxic potencies, followed by the CSC from the TL cigarette, whereas the CSC from the TW cigarette produced the least severe mutagenic and genotoxic potencies. CONCLUSIONS: The results of this study suggest that the mutagenic and genotoxic potencies of the TL and TW cigarettes were weaker than those of the 3R4F cigarette. Further study on standardized concepts of toxic equivalents for cigarettes needs to be conducted for more extensive use of in vitro tests.

Successful administration of iodinated contrast media in a patient with anaphylaxis to multiple contrast media

Although hypersensitivity reactions to iodinated contrast media (ICM) are uncommon, their clinical impacts are considerable because of their wide use and potential fatality. The best way to prevent ICM-induced hypersensitivity is to avoid re-exposure to the ICM. However, ICM use is inevitable in the evaluation of many diseases. A 64-year-old male with renal cell carcinoma presented with anaphylaxis after computed tomography (CT) using iohexol. Intradermal test results were positive to iohexol, iomeprol, and ioversol. The following 3 CT scans using the test-negative agents iopromide, iopamidol, and iobitridol still provoked hypersensitivity reactions despite premedication using intravenous antihistamine and corticosteroid. For the next step, iodixanol, a nonionic iso-osmolar dimer, was tested by intravenous graded challenges in addition to the intradermal skin test, which and was confirmed to be negative. The patient underwent CT scan using iodixanol after premedication with chlorpheniramine 4 mg and methylprednisolone 40 mg, and hypersensitivity reactions did not recur. We report a case of a patient showing hyper reactivity to multiple ICMs despite negative intradermal skin tests, who eventually underwent successful enhanced CT scans after choosing ICM by the graded challenge test.