Association of Cough Severity with Asthma Control and Quality of Life in Patients with Severe Asthma.

PURPOSE: Symptoms are important components in determining asthma control and in the adjustment of treatment levels. However, clinical relevance of cough in severe asthma is not well-understood. This study aimed to evaluate the severity and association of cough with patient-reported outcomes (PROs) in patients with severe asthma. METHODS: This study analyzed cross-sectional data from the Korean Severe Asthma Registry. The severity of coughing and wheezing symptoms was assessed using a Visual Analog Scale (VAS) ranging from 0 to 100 for each symptom. Additionally, PROs included the Asthma Control Test (ACT), the Severe Asthma Questionnaire (SAQ), and the EuroQoL 5-Dimension (EQ-5D) index. Multivariate linear regression analysis was employed to explore the relationship between cough severity and other PRO scores. RESULTS: A total of 498 patients with severe asthma (age: 57.9 ± 13.1 years, females: 60.2%) were analyzed. The cough VAS score was higher than the wheeze score (median 30, [interquartile range 10-50] vs. 20 [0-50]; P < 0.001). Additionally, 22.5% of patients ranked in a higher tertile for cough severity compared to wheezing, while 18.5% ranked higher for wheezing severity than cough. Significant correlations were observed between cough and wheeze VAS scores (r = 0.61, P < 0.05) and between each symptom's VAS score and the SAQ (cough: r = -0.41, P < 0.001; wheeze: r = -0.52, P < 0.001), ACT scores (cough: r = -0.50, P < 0.001; wheeze: r = -0.63, P < 0.001) and EQ-5D index (cough: r = -0.40, P < 0.001; wheeze: r = -0.45, P < 0.001). In univariate regression analysis, the cough VAS score had weaker descriptive power (R2) values than the wheeze VAS score in relation to the PRO measures. Nevertheless, cough severity remained significantly associated with ACT, SAQ scores and EQ-5D index in multivariate analyses adjusted for wheeze severity and other confounders. CONCLUSION: Cough frequently presents as a severe symptom in patients with severe asthma and could have distinct impact on asthma control and quality of life.

Real-World Effectiveness of Biologics in Patients With Severe Asthma: Analysis of the KoSAR.

PURPOSE: Severe asthma is associated with high morbidity and healthcare utilization; however, treatment options for these patients are limited. This study aimed to determine the therapeutic effects of biologics in clinical practice. METHODS: This multicenter, retrospective cohort study included 136 patients who received biologics for at least 4 months between September 2017 and July 2022 at 25 medical centers affiliated with the Korean Severe Asthma Registry (KoSAR). The study evaluated the treatment effects, including acute exacerbation rates, maintenance of oral corticosteroid dosages, lung function, quality of life, blood eosinophil count, and fractional exhaled nitric oxide (FeNO) levels, by comparing measurements before and after 4 months of biologic treatment. Responses for each medication was evaluated based on the Global Evaluation of Treatment Effectiveness score, and any adverse reactions were summarized. RESULTS: With the administration of biologics over the course of 4 months, there was a reduction in asthma acute exacerbations, a significant improvement in lung function, and a significant decrease in daily maintenance dose of oral steroid. Blood eosinophil counts decreased in the mepolizumab and reslizumab groups, while FeNO levels decreased only in the dupilumab group. The Asthma Control Test, Quality of Life Questionnaire for Adult Korean Asthmatics, and the EuroQol-visual analogue scale scores showed a significant improvement. Most patients (80.15%) responded to the biologic treatment. Meanwhile, non-responders often had chronic rhinosinusitis as a comorbidity, exhibited lower lung function, and required higher doses of oral steroids. No severe adverse events were reported. CONCLUSIONS: Biologics are highly effective in Korean patients with Type 2 severe asthma, significantly reducing acute exacerbation rates and doses of oral corticosteroids, while also improving lung function. Therefore, it seems beneficial to administer biologics without any restrictions to patients exhibiting Type 2 severe asthma.

Characteristics of Severe Asthma in the Elderly: Observations From the Korean Severe Asthma Registry (KoSAR).

PURPOSE: Few studies have compared the clinical characteristics of severe asthma (SA) in elderly patients compared to that in nonelderly patients. METHODS: We analyzed data from the Korean SA Registry, a nationwide, real-world observational study of SA in Korea. The baseline clinical characteristics, disease control status, and medication use of the patients were compared between elderly (≥ 65 years) and nonelderly groups. RESULTS: Of the 864 patients with SA, 260 (30.1%) were in the elderly group. The elderly group had lower atopy rate, but had higher prevalence of chronic obstructive pulmonary disease (COPD), hypertension, and osteoporosis than did the nonelderly group. The elderly group had a lower rate of type 2 inflammation and lower levels of forced expiratory volume in 1 second (FEV1) (% predicted) and FEV1/forced vital capacity ratio than did the nonelderly group (P < 0.05 for all). However, asthma symptom scores and the frequency of asthma exacerbation were not significantly different between the 2 groups. Of controller medications, biologics were less frequently used in the elderly group (P < 0.05 for all). CONCLUSIONS: SA in the elderly is characterized by lower lung function, less type 2-low airway inflammation, and comorbidity with COPD. These findings are being taken into consideration in the management of elderly patients with SA in real-world clinical practice.

Work-related asthma in adults with severe asthma from the Korean Severe Asthma Registry (KoSAR).

Background: Exposure to allergens or irritants in the workplace may affect asthma control and the quality of life (QoL) of patients with asthma. Objective: To examine the prevalence and characteristics of work-related asthma (WRA) in adult patients with severe asthma. Methods: We analyzed data from the Korean Severe Asthma Registry (KoSAR), which is a nationwide multicenter observational study on severe asthma in Korea. Severe asthma was defined according to the American Thoracic Society (ATS) and the European Respiratory Society (ERS) guidelines. WRA was identified on the basis of asthma symptom aggravation at the workplace, as indicated by responses to a structured questionnaire. We compared the demographic and clinical characteristics and QoL between adult patients with severe asthma and WRA and those without WRA. Results: Among 364 patients with severe asthma who were employed at the time of enrollment, 65 (17.9%) had WRA. There were no significant differences in age, sex, obesity, or smoking history between the WRA and non-WRA groups. However, individuals with WRA exhibited a higher prevalence of anxiety (7.7% vs 2.4%, P = 0.046) and depression (12.3% vs 3.7%, P = 0.010) than those without. The levels of asthma control, lung function, and frequency of asthma exacerbations were similar between the two groups, but patients with WRA reported lower QoL, as determined by the Quality of Life Questionnaire for Adult Korean Asthmatics (56.6 ± 14.6 vs. 63.5 ± 13.9, P < 0.001). Conclusion: Patients with severe asthma and WRA are more likely to experience anxiety and depression and have lower QoL than those without WRA.

Relationship of computed tomography-based measurements with symptom perception and quality of life in patients with severe asthma.

BACKGROUND: Symptom perception and quality of life (QOL) are important domains for properly managing severe asthma. This study aimed to assess the relationship between airway structural and parenchymal variables measured using chest computed tomography (CT) and subjective symptom perception and QOL in patients with severe asthma enrolled in the Korean Severe Asthma Registry. METHODS: This study used CT-based objective measurements, including airway wall thickness (WT), hydraulic diameter, functional small airway disease (fSAD), and emphysematous lung (Emph), to assess their association with subjective symptom (cough, dyspnea, wheezing, and sputum) perception measured using the visual analog scale, and QOL measured by the Severe Asthma Questionnaire (SAQ). RESULTS: A total of 94 patients with severe asthma were enrolled in this study. The WT and fSAD% were significantly positively associated with cough and dyspnea, respectively. For QOL, WT and Emph% showed significant negative associations with the SAQ. However, there was no significant association between lung function and symptom perception or between lung function and QOL. CONCLUSION: Overall, WT, fSAD%, and Emph% measured using chest CT were associated with subjective symptom perception and QOL in patients with severe asthma. This study provides a basis for clarifying the clinical correlates of imaging-derived metrics and for understanding the mechanisms of respiratory symptom perception.

Isolated respiratory tract microorganisms and clinical characteristics in asthma exacerbation of obese patients: a multicenter study.

BACKGROUND: Viral infection is a risk factor for asthma exacerbation (AE). However, bacterial infections related to AE in adults are poorly known. On the other hand, obese patients with asthma have their own clinical and biological characteristics compared with non-obese patients. METHODS: We investigated the differences in isolated pathogens for AE between obese and non-obese patients with asthma. We included 407 patients with AE from 24 medical centers in Korea. Microorganisms isolated from culture, RT-PCR or serologic tests using lower respiratory tract specimens were retrospectively investigated. RESULTS: A total of 171 obese and 236 non-obese patients with asthma were included for analysis. Compared to non-obese patients, obese patients were associated with women (77.2% vs. 63.6%), never smoker (82.5% vs. 73.9%), shorter duration of asthma (7.9 ± 8.4 vs. 10.5 ± 10.1 years), less history of pulmonary tuberculosis (8.8% vs. 17.4%), and more comorbidity of allergic rhinitis (48.5% vs. 0.8%). Viral and/or bacterial infections were detected in 205 patients (50.4%) with AE. The numbers of patients with viral only, bacterial only, or both infections were 119, 49, and 37, respectively. The most commonly isolated bacterium was Streptococcus pneumoniae, followed by Pseudomonas aeruginosa and Chlamydia pneumoniae. Obese patients showed a lower incidence of Chlamydia pneumoniae infection. In the non-obese group, bacterial infection, especially Chlamydia pneumoniae infection, was significantly associated with the duration of systemic corticosteroid use (13.6 ± 19.8 vs. 9.7 ± 6.7 days, p = 0.049). CONCLUSION: Bacterial infection was associated with a longer period of corticosteroid use in the non-obese group. Acute Chlamydia pneumoniae infection was less associated with obese patients with AE. Further well-designed studies are needed to evaluate microorganisms and the efficacy of antibiotics in patients with AE.

COVID-19 organizing pneumonia with sudden dyspnea in an asymptomatic survivor.

This case shows that COVID-19 survivors can develop delayed-type pneumonia with sudden respiratory distress that responds dramatically to steroid treatment after remaining asymptomatic for more than several weeks, although pulmonary involvement of post-COVID-19 syndrome is often accompanied by long-term and severe sequelae such as pulmonary fibrosis.

Structural and functional features of asthma participants with fixed airway obstruction using CT imaging and 1D computational fluid dynamics: A feasibility study.

Asthma with fixed airway obstruction (FAO) is associated with significant morbidity and rapid decline in lung function, making its treatment challenging. Quantitative computed tomography (QCT) along with data postprocessing is a useful tool to obtain detailed information on airway structure, parenchymal function, and computational flow features. In this study, we aim to identify the structural and functional differences between asthma with and without FAO. The FAO group was defined by a ratio of forced expiratory volume in 1 s (FEV1 ) to forced vital capacity (FVC), FEV1 /FVC <0.7. Accordingly, we obtained two sets of QCT images at inspiration and expiration of asthma subjects without (N = 24) and with FAO (N = 12). Structural and functional QCT-derived airway variables were extracted, including normalized hydraulic diameter, normalized airway wall thickness, functional small airway disease, and emphysema percentage. A one-dimensional (1D) computational fluid dynamics (CFD) model considering airway deformation was used to compare the pressure distribution between the two groups. The computational pressures showed strong correlations with the pulmonary function test (PFT)-based metrics. In conclusion, asthma participants with FAO had worse lung functions and higher-pressure drops than those without FAO.

NecroX Improves Polyhexamethylene Guanidine-induced Lung Injury by Regulating Mitochondrial Oxidative Stress and Endoplasmic Reticulum Stress.

Various environmental compounds are inducers of lung injury. Mitochondria are crucial organelles that can be affected by many lung diseases. NecroX is an indole-derived antioxidant that specifically targets mitochondria. We aimed to evaluate the therapeutic potential and related molecular mechanisms of NecroX in preclinical models of fatal lung injury. We investigated the therapeutic effects of NecroX on two different experimental models of lung injury induced by polyhexamethylene guanidine (PHMG) and bleomycin, respectively. We also performed transcriptome analysis of lung tissues from PHMG-exposed mice and compared the expression profiles with those from dozens of bleomycin-induced fibrosis public data sets. Respiratory exposure to PHMG and bleomycin led to fatal lung injury manifesting extensive inflammation followed by fibrosis. These specifically affected mitochondria regarding biogenesis, mitochondrial DNA integrity, and the generation of mitochondrial reactive oxygen species in various cell types. NecroX significantly improved the pathobiologic features of the PHMG- and bleomycin-induced lung injuries through regulation of mitochondrial oxidative stress. Endoplasmic reticulum stress was also implicated in PHMG-associated lung injuries of mice and humans, and NecroX alleviated PHMG-induced lung injury and the subsequent fibrosis, in part, via regulation of endoplasmic reticulum stress in mice. Gene expression profiles of PHMG-exposed mice were highly consistent with public data sets of bleomycin-induced lung injury models. Pathways related to mitochondrial activities, including oxidative stress, oxidative phosphorylation, and mitochondrial translation, were upregulated, and these patterns were significantly reversed by NecroX. These findings demonstrate that NecroX possesses therapeutic potential for fatal lung injury in humans.

A Rare Case of Familial Schwannomatosis Showing Intrafamilial Variability with Identification of a Shared Novel Germline SMARCB1 Mutation.

Schwannomatosis is characterized by the presence of multiple schwannomas without landmarks of NF2. It is considered the rarest form of neurofibromatosis (NF). Here, we report the first case of familial schwannomatosis with regard to the segmental/generalized phenotype, in which the proband and the daughter present a distinct phenotype in this classification. The proband presents a generalized, painless, extradural type of schwannomatosis, while the daughter shows a segmental, painful, intradural type of schwannomatosis. Whole-exome sequencing of the affected individuals revealed a shared novel SMARCB1 gene mutation (c.92A > G, p.Glu31Gly) despite the clinical variability. We thus suggest two points in the diagnosis of familial schwannomatosis: The identified novel germline SMARCB1 variant can be reflective of a phenotypical progression from a segmental to a generalized type of schwannomatosis, or an intrafamilial variability in inherited schwannomatosis, which was not reported in previous literature. The specific combination of somatic NF2 mutations may be a major factor in regulating the severity and scope of the resulting phenotype in schwannomatosis.

Viral Infection and Airway Epithelial Immunity in Asthma.

Viral respiratory tract infections are associated with asthma development and exacerbation in children and adults. In the course of immune responses to viruses, airway epithelial cells are the initial platform of innate immunity against viral invasion. Patients with severe asthma are more vulnerable than those with mild to moderate asthma to viral infections. Furthermore, in most cases, asthmatic patients tend to produce lower levels of antiviral cytokines than healthy subjects, such as interferons produced from immune effector cells and airway epithelial cells. The epithelial inflammasome appears to contribute to asthma exacerbation through overactivation, leading to self-damage, despite its naturally protective role against infectious pathogens. Given the mixed and complex immune responses in viral-infection-induced asthma exacerbation, this review examines the diverse roles of airway epithelial immunity and related potential therapeutic targets and discusses the mechanisms underlying the heterogeneous manifestations of asthma exacerbations.

Self-management model based on information-motivation-behavioral skills model in patients with chronic obstructive pulmonary disease.

AIM: To develop and test a predictive model of self-management based on the theory of the information-motivation-behavioural skills model and previous literature on self-management for patients with chronic obstructive pulmonary disease (COPD). DESIGN: A descriptive, correlational, cross-sectional design was used. METHODS: A convenience sample recruited 248 patients with COPD from the pulmonary medicine clinic in South Korea between July 2020 and June 2021. We used self-administrated, structured questionnaires for dyspnoea, health status, knowledge, attitude, social support, self-efficacy and self-management. Data were analysed using path analysis to test a self-management model for patients with COPD. RESULTS: Gender, COPD self-management knowledge, social support and COPD self-efficacy had a direct effect on COPD self-management. Dyspnoea, Global Initiative for Chronic Obstructive Lung Disease stage, health status, COPD self-management attitude and social support had an indirect effect on self-management in patients with COPD. These variables explained 43.2% of the total variance for self-management in patients with COPD. CONCLUSIONS: When assessing self-management of COPD; demographic and clinical factors, knowledge, attitudes, social support and self-efficacy included in the information-motivation-behavioural skills model should be considered together.

Tracheal neurofibroma treated by repeated flexible bronchoscopic cryotherapy: A case report.

RATIONALE: Isolated endotracheal neurofibroma is very rare. The majority of neurofibromas are benign, but rarely, they can become cancerous. Furthermore, symptomatic neurofibroma is usually treated by surgical resection. Recently, several alternative options for surgical resection of this airway pathology have been suggested and developed, including bronchoscopic cryotherapy. Nevertheless, there has been no report on the application of repeated flexible bronchoscopic cryotherapy to remove an endotracheal neurofibroma. PATIENT CONCERNS: A 65-year-old woman presented with progressive dyspnea and productive cough. Chest computed tomography scans revealed a 1.5-cm polypoid-shaped mass with fat attenuation and mild enhancement in the distal trachea. Flexible bronchoscopic cryotherapy was performed to remove the mass and confirm the diagnosis. DIAGNOSIS: Pathologically, the mass was diagnosed as an endotracheal neurofibroma occupying the distal tracheal lumen. INTERVENTIONS: The endotracheal neurofibroma was completely removed with repeated flexible bronchoscopic cryotherapy instead of surgical resection. OUTCOMES: Follow-up flexible bronchoscopy also revealed that there was no regrowth of the neurofibroma. Up to 18 months after the completion of serial cryotherapy, the patient had no recurrent symptoms or complaints. LESSONS: Flexible bronchoscopic cryotherapy can be performed repeatedly for therapeutic purposes for airway tumors. It is recommended to consider flexible bronchoscopic cryotherapy as an alternative therapeutic option for patients with central airway obstruction due to tumorous lesions such as neurofibromas.

Prescription Patterns of Oral Corticosteroids for Asthma Treatment and Related Asthma Phenotypes in University Hospitals in Korea.

PURPOSE: Oral corticosteroids (OCSs) are frequently prescribed for asthma management despite their adverse effects. An understanding of the pattern of OCS treatment is required to optimize asthma treatment and reduce OCS usage. This study evaluated the prescription patterns of OCSs in patients with asthma. METHODS: This is a retrospective multicenter observational study. We enrolled adult (≥18 years) patients with asthma who had been followed up by asthma specialists in 13 university hospitals for ≥3 years. Lung function tests, the number of asthma exacerbations, and prescription data, including the days of supply and OCS dosage, were collected. The clinical characteristics of OCS-dependent and exacerbation-prone asthmatic patients were evaluated. RESULTS: Of the 2,386 enrolled patients with asthma, 27.7% (n = 660) were OCS users (the median daily dose of OCS was 20 mg/day prednisolone equivalent to a median of 14 days/year). OCS users were more likely to be female, to be treated at higher asthma treatment steps, and to show poorer lung function and more frequent exacerbations in the previous year than non-OCS users. A total of 88.0% of OCS users were treated with OCS burst with a mean dose of 21.6 ± 10.2 mg per day prednisolone equivalent to 7.8 ± 3.2 days per event and 2.4 times per year. There were 2.1% (51/2,386) of patients with OCS-dependent asthma and 9.5% (227/2,386) with exacerbation-prone asthma. These asthma phenotypes were consistent over the 3 consecutive years in 47.1% of OCS-dependent asthmatic patients and 34.4% of exacerbation-prone asthmatic patients when assessed annually over the 3-year study period. CONCLUSIONS: We used real-world data from university hospitals in Korea to describe the OCS prescription patterns and relievers in asthma. Novel strategies are required to reduce the burden of OCS use in patients with asthma.

COVID-19 Vaccine-associated Anaphylaxis and Allergic Reactions: Consensus Statements of the KAAACI Urticaria/Angioedema/Anaphylaxis Working Group.

In the era of novel coronavirus epidemics, vaccines against coronavirus disease 2019 (COVID-19) have been recognized as the most effective public health interventions to control the pandemic. An adverse event following immunization (AEFI) is defined as any untoward occurrence following immunization, and the majority of AEFIs are caused by protective immune responses stimulated by vaccines. Most of the reported AEFIs are not serious, and many are not immunologically mediated or even reproducible on re-exposure. However, uncommon severe allergic adverse reactions, such as anaphylaxis or other allergic reactions, can occur after vaccinations. Confirmed allergic reactions to vaccines may be caused by residual non-human protein, preservatives, or stabilizers in the vaccine formulation (also known as excipients). There are 2 main potential allergenic/immunogenic excipients in COVID-19 vaccines, polyethylene glycol (PEG) and polysorbate 80. PEG, also known as macrogol, is an ingredient in various laxatives and injectable formulations, such as depot steroids. Polysorbate 80 is present in various medical products, creams, ointments, lotions, and medication tablets. Contraindications to the administration of COVID-19 vaccines include a previous history of severe allergic reactions to the first dose of COVID-19 vaccine or proven hypersensitivity to a vaccine component, such as PEG or polysorbate 80. Anaphylaxis or other allergic reactions following immunization can cause fear and loss of confidence in the safety of vaccines among the public. A better understanding of these events is thought to help alleviate concerns about the current COVID-19 vaccines and provide reassurance to the general population by analyzing the exact incidence of anaphylaxis and potential risk factors. COVID-19 vaccine-associated anaphylaxis could be prevented and managed by risk stratification based on our local and global experience.

Specialist Perception of Severe Asthma in Korea: A Questionnaire Survey.

The Working Group on Severe Asthma of the Korean Academy of Allergy and Clinical Immunology recently published an expert opinion paper on the management of severe asthma in Korea. When developing a consensus, the working group encountered several diagnostic and treatment issues and decided to perform a questionnaire survey of Korean specialists with regard to severe asthma. An e-mail with a uniform resource locator link to the questionnaire was sent to 121 asthma specialists, of whom 44.6% responded. The most commonly accepted definitions of severe asthma were a history of fatal exacerbation or an asthma-triggered need for mechanical ventilation, 3-4 oral corticosteroid (OCS) bursts/year, and maintenance of OCS therapy for 3-6 months per year. Before diagnosing severe asthma, most physicians contemplate chest computed tomography, seek to control chronic rhinosinusitis, and consider poor inhaler compliance. For patients with uncontrolled severe asthma accompanied by type 2 (T2)-high inflammation, most biologics available in Korea were considered appropriate, but gaps were apparent in terms of T2-low asthma treatments. These findings about specialist perception of diagnosis and treatment of severe asthma will inform the use of emerging new drugs and facilitate personalized therapy.

Characteristics of Specialist-Diagnosed Asthma-COPD Overlap in Severe Asthma: Observations from the Korean Severe Asthma Registry (KoSAR).

BACKGROUND: While the clinical characteristics and outcomes of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) have been frequently compared with those of COPD or asthma, the prevalence and features of ACO in patients with severe asthma are unclear. OBJECTIVES: Evaluation of the prevalence and clinical features of ACO using the Korean severe asthma registry. METHODS: At the time of registration, ACO was determined in patients with severe asthma by attending specialists. Patients were classified into ACO and non-ACO groups, and the demographic and clinical characteristics of these two groups were compared. RESULTS: Of 482 patients with severe asthma, 23.7% had ACO. Patients in the ACO group were more likely to be male (P < .001), older (P < .001), and ex- or current smokers (P < .001) compared with those in the non-ACO group. Patients in the ACO group had lower mean forced expiratory volume in 1 second (P < .001) and blood eosinophil percentage (P = .006), but higher blood neutrophil percentage (P = .027) than those in the non-ACO group. The ACO group used more inhaled long-acting muscarinic antagonist (P < .001), methylxanthine (P = .001), or sustained systemic corticosteroid (P = .002). In addition, unscheduled emergency department visits due to exacerbation were more frequent in the ACO group (P = .006). CONCLUSION: Among patients with severe asthma, those with ACO were older, predominantly male, and were more likely to have a smoking history than those with asthma only. Patients with ACO used more systemic corticosteroid and had more frequent exacerbations related to emergency department visits than those with severe asthma only.

Evaluation and Management of Difficult-to-Treat and Severe Asthma: An Expert Opinion From the Korean Academy of Asthma, Allergy and Clinical Immunology, the Working Group on Severe Asthma.

Severe asthma (SA) presents in about 3%-5% of adult asthmatics and is responsible for over 60% of asthma-related medical expenses, posing a heavy socioeconomic burden. However, to date, a precise definition of or clear diagnostic criteria for SA have not been established, and therefore, it has been challenging for clinicians to diagnose and treat this disease. Currently, novel biologics targeting several molecules, such as immunoglobulin E, interleukin (IL)5, and IL4/IL13, have emerged, and many new drugs are under development. These have brought a paradigm shift in understanding the mechanism of SA and have also provided new treatment options. However, we need to agree on a precise definition of and its diagnostic criteria for SA. Additionally, it is necessary to explain the diagnostic criteria and to summarize current standard and additional treatment options. This review is an experts' opinion on SA from the Korean Academy of Asthma, Allergy, and Clinical Immunology, the Working Group on Severe Asthma, and aims to provide a definition of and diagnostic criteria for SA, and propose future direction for SA diagnosis and management in Korea.