Asthma is a chronic respiratory disease characterized by persistent airway inflammation and irreversible airway remodeling. Current treatment strategies primarily rely on symptom relievers and controllers, which do not fundamentally modify the underlying disease pathology, and thus asthma has long been regarded as being difficult to cure. However, long-term follow-up studies in various cohorts have reported sustained absence of symptoms, or clinical remission. In pediatric asthma, several birth cohort studies have demonstrated clinical remission rates approaching 50%, and even in disease cohorts applying more stringent diagnostic criteria, remission has been still observed in children. Higher remission rates have been reported in individuals with younger age at onset, male sex, nonatopic phenotypes without sensitization to inhalant allergens, preserved lung function, and lower bronchial hyperresponsiveness. Immunotherapy, which can modify the natural course of allergic diseases, has been shown to reduce bronchial hyperresponsiveness and increase remission rates in asthma. Recently, the development and widespread use of biologics have enabled remission to be considered as a therapeutic goal even in severe asthma, prompting efforts to standardize its definition. In the current era of diverse therapeutic options and improved clinical outcomes, establishing both more precise and practical evaluation and definition of asthma remission will be pivotal for achieving personalized and precision asthma management.

Rhinoviruses are the most prevalent respiratory viruses across age groups, responsible for a wide spectrum of illnesses ranging from mild upper respiratory symptoms to lower airway involvement. Moreover, rhinovirus infection is also a major driver of asthma exacerbation and development, imposing a substantial disease burden. Rhinoviruses are classified into three species: Rhinovirus A, Rhinovirus B, and Rhinovirus C, each utilizing distinct host cell receptors and exhibiting different clinical patterns. Rhinovirus A and Rhinovirus C are more frequently associated with clinically significant disease outcomes compared to Rhinovirus B. Rhinovirus C binds to cadherin-related family member 3 (CDHR3), and a missense variant in CDHR3 (rs6967330) increases epithelial expression of the receptor, enhancing susceptibility to infection and severe illness, particularly in early life. Rhinovirus infection induces complex immune responses, characterized by impaired interferon signaling, type 2 inflammation, and epithelial barrier disruption. In individuals with asthma, altered interferon responses and T2-high immune profiles are closely linked to rhinovirus-induced exacerbations.In infants with atopic traits, such as eosinophilia, allergen sensitization, or a family history of allergic diseases, rhinovirus infection is strongly associated with subsequent development of asthma. Rhinovirus vaccine is needed to prevent severe respiratory infections and asthma exacerbations, particularly in vulnerable populations. Rhinovirus vaccine development has been challenging due to extensive antigenic diversity and limited cross-protective immunity. Recent progress in high-valency inactivated vaccines has demonstrated the feasibility of eliciting broad neutralizing responses. Prioritizing rhinovirus types linked to greater clinical severity may enable targeted vaccine strategies for high-risk populations, offering a promising approach to reducing the global burden of rhinovirus-associated illnesses.

Childhood asthma is a common chronic respiratory disease with a heterogeneous course, including remission, persistence, and relapse. Although about 50% of the affected children achieve clinical remission, many relapse; furthermore, airway inflammation or lung function impairment may persist even during remission. By synthesizing findings from cohort studies conducted in the United Kingdom, New Zealand, Australia, the United States, Canada, Sweden, The Netherlands, Denmark, Turkey, and Iran, we reviewed the long-term course of childhood asthma and prognostic factors influencing remission. Clinical remission rates ranged from 25% to 65% across cohorts, whereas complete remission defined as normal lung function with the absence of bronchial hyperresponsiveness was limited to 15%–30%. Even among the patients in clinical remission, many continued to show reduced lung function, bronchial hyperresponsiveness, and airway inflammation. Prognostic factors for remission failure and persistence included low forced expiratory volume in 1 second/forced vital capacity ratio, bronchial hyperresponsiveness, female sex, early onset, disease severity, atopy, parental history of asthma, and high healthcare utilization shortly after diagnosis. In contrast, children with normal lung function, normal eosinophil count and normal airway responsiveness had higher than 80% likelihood of remission in adulthood. Earlylife bronchiolitis, severe asthma, sensitization to house dust mite, Alternaria, and furred animals, elevated fractional exhaled nitric oxide levels and peripheral eosinophilia were associated with persistent or relapsing asthma. In addition, non-White populations showed lower remission rates compared with White populations. Therefore, symptom control, preservation of lung function, and prevention of exacerbations remain the most pragmatic treatment goals, while early intervention strategies based on prognostic factors may help reduce persistence and relapse.

Purpose: Laryngomalacia exhibits diverse morphological patterns, severities, and comorbidities. Defining clinical phenotypes could improve management and prognosis. This study aimed to identify and characterize phenotypes using cluster analysis and to evaluate prognostic factors. Methods: We retrospectively reviewed records of 195 children diagnosed with laryngomalacia between 2014 and 2023 using flexible laryngoscopy or bronchoscopy. Demographics, endoscopic findings, comorbidities, and outcomes up to 1 year of age were collected. Hierarchical cluster analysis was conducted using 10 clinical variables. Results: Four phenotypes emerged: cluster 1 (n= 75, 38.5%), Groningen Laryngomalacia Classification System (GLCS) type 1 dominant-mild; cluster 2 (n= 35, 17.9%), GLCS type 2 dominant-mild; cluster 3 (n= 40, 20.5%), severe with multiple comorbidities; and cluster 4 (n = 45, 23.1%), GLCS combined-type moderate. Distinct clinical courses were observed. Cluster 3 showed the highest rates of surgical intervention (32.5%, P < 0.001), pediatric intensive care unit admission (17.5%, P = 0.016), and Emergency Department (ED) visits (60.0%, P= 0.013) for respiratory problems during the first year. When stratified by comorbidities, children with multiple comorbidities, particularly those with major feeding problems had a higher risk of hospitalization (adjusted odds ratio [aOR], 2.65;95% confidence interval [CI], 1.11–6.33) and ED visits (aOR, 3.17; 95% CI, 1.39–7.23), even after adjusting for sex and severity. Conclusion Four clinically meaningful phenotypes of laryngomalacia were identified from the cluster analysis based on morphology, comorbidities, and disease severity. Children with multiple comorbidities accompanied by feeding problems had the greatest risk of hospitalization and ED visits for respiratory problems within the first year, even after adjusting for the severity of laryngomalacia.

Purpose: This study investigated sensitization patterns and potential cross-sensitization among tree pollens of the Betulaceae (birch, alder, hazel) and Fagaceae (oak, beech) families, based on skin prick test results. Comparisons were also made with non-tree allergens, including mugwort, cat, and cockroach. Methods: We retrospectively analyzed skin prick test results of 1,812 patients evaluated between 2010 and 2013. A positive reaction was defined as an allergen-to-histamine wheal ratio of 1.0 or higher. Sensitization rates were calculated, and cross-sensitization was assessed by analyzing simultaneous positivity rates, conditional probabilities, and Pearson correlation coefficients based on raw skin prick test scores (0, 2, 3, and 4). Results: The sensitization rates were 12.4% for birch, 11.0% for alder, 11.1% for hazel, 14.6% for oak, and 14.1% for beech. Strong correlations were observed within Betulaceae (r= 0.78–0.85) and within Fagaceae (r= 0.76). Moderate to strong correlations were also found between Betulaceae and Fagaceae (r = 0.70–0.80), suggesting inter-family cross-sensitization. Simultaneous positivity and conditional probabilities were also high within and between Betulaceae and Fagaceae, reinforcing the observed cross-sensitization patterns. In contrast, mugwort, cat, and cockroach showed weak correlations (r = 0.35–0.37 for mugwort; r ≤ 0.26 for cat and cockroach) and low simultaneous positivity and conditional probabilities, indicating limited cross-reactivity. All correlations were statistically significant (P < 0.001). Conclusion These findings demonstrate strong associations among tree pollen allergens within and between Betulaceae and Fagaceae, reflecting molecular-level cross-reactivity, supporting their clinical relevance in allergy diagnosis and treatment planning.

Episodic angioedema with eosinophilia (EAE) is a rare disorder characterized by recurrent episodes of angioedema accompanying peripheral blood eosinophilia. Oral corticosteroids (OCS) are the primary treatment; however, concerns remain regarding potential adverse effects associated with frequent or long-term use of OCS. Although the pathophysiological mechanisms underlying EAE remain unclear, studies have reported an association between T-cell clonality and subsequent elevation of interleukin (IL)-5 levels. A 43-year-old male had experienced facial and hand edema accompanied by eosinophilia since 2020. During episodes of angioedema, he exhibited febrile sensation and rapid weight gain within a few hours, along with dyspnea and severe pruritus. To control symptoms, continuous OCS therapy was required. In 2021, he was treated with anti-IL 5 antibody (reslizumab 200 mg) for 3 months, which was ineffective. Subsequently, he visited Ajou University Hospital in November 2022 for additional disease management. He had been taking deflazacort (8–32 mg/day) and cyclosporine (75–200 mg/day); however, his EAE was not controlled during which higher doses of OCS had been used. Laboratory findings revealed variations in blood eosinophils according to the symptom status and OCS dose, and general reductions in immunoglobulin G2 (IgG2), IgG3, and IgG levels due to long-term use of OCS. Since anti-interleukin (IL)-5 receptor antibody (benralizumab, 30 mg) and intravenous immunoglobulin were regularly administered at 4-week intervals, no further attacks of EAE have been observed with stopping OCS treatment. Severe EAE refractory to anti-IL-5 antibody as well as OCS therapy could be controlled by anti-IL-5 receptor antibody as an effective steroid-sparing agent.

Hypersensitivity reactions (HSRs) to iodinated contrast media (ICM) can range from mild cutaneous symptoms to life-threatening anaphylaxis. In patients with a history of ICM hypersensitivity, avoidance of the culprit agent is generally recommended. This case report describes a successful desensitization in a 56-year-old man with recurrent HSRs to multiple agents including ioversol, iohexol, iobitridol, and iopamidol. Intradermal testing was performed to identify potentially safe alternatives; however, all tested agents, including iohexol, ioversol, iobitridol, iopamidol, iodixanol, iomeprol, and iopromide, yielded positive results. Given the clinical necessity of transcatheter arterial chemoembolization, a 13-step rapid desensitization protocol with iodixanol was implemented. The procedure was completed without any breakthrough reactions. This case highlights desensitization as a feasible and effective strategy for patients with hypersensitivity to multiple ICM agents.

Common variable immunodeficiency (CVID) is a heterogeneous primary immunodeficiency characterized by reduced levels of immunoglobulin (Ig)G, with or without IgA and/or IgM deficiency, and hypogammaglobulinemia. Clinical manifestations are diverse, ranging from recurrent infections to autoimmune and allergic diseases. While CVID has been rarely reported in the Korean population, particularly in adults, we report 2 adult cases of CVID comorbid with asthma and Behcet’s disease. The first case of a 53-year-old with severe allergic asthma and chronic rhinosinusitis experienced recurrent respiratory infections, stomatitis, and cystitis requiring frequent antibiotic treatment. Laboratory findings indicated a T2-high asthma phenotype, with elevated serum total IgE specific IgE to dog hair and fractional exhaled nitric oxide. Immunological evaluation revealed decreased serum IgG (including IgG1 and IgG2), along with hypogammaglobulinemia. She had been treated with regular anti-IgE antibody therapy and intravenous immunoglobulin replacement therapy (IVIGRT). The second case of a 38-year-old with Behçet’s disease and uveitis had bronchial asthma and rhinitis that were exacerbated by recurrent infections despite standard asthma therapy. Laboratory findings revealed a T2-low phenotype and a marked reduction in serum IgG (including IgG1, IgG2, and IgG4), and hypogammaglobulinemia, consistent with CVID.IVIGRT effectively reduced asthma exacerbations and infection episodes in both cases. These cases highlight the clinical heterogeneity of CVID and its potential overlap with allergic and autoimmune diseases. Immunological evaluation of underlying immunodeficiency should be considered in adult patients with asthma who present with frequent exacerbations and recurrent infections. Early diagnosis and IVIGRT can prevent complications and improve outcomes.

Purpose: Asthma is characterized by chronic type 2/eosinophilic inflammation in the airway mucosa. This study aimed to explore the clinical value of 2 cutoffs of blood eosinophil counts (≥ 300/μL and ≥ 150/μL) in eosinophilic asthma, with relation to eosinophilderived neurotoxin (EDN), a surrogate marker of eosinophilic activity. Methods: To compare clinical features and eosinophil-related mediators according to 2 cutoffs of peripheral blood eosinophil counts (≥ 300/μL and ≥ 150/μL), 137 adult asthmatics who had maintained antiasthmatic medications, including inhaled corticosteroid and long-acting beta 2 agonist, without biologics, were enrolled. EDN levels in serum, urine and sputum were measured by enzymelinked immunosorbent assay. Results: Patients with asthma and higher blood eosinophil counts ( ≥ 300/μL) had a higher prevalence of severe asthma, chronic rhinosinusitis, partly controlled/uncontrolled status, and higher levels of sputum eosinophils and EDN in serum/sputum than those with lower blood eosinophil counts (< 300/μL). When compared between patients with asthma having higher blood eosinophils ( ≥ 150/μL) and those with lower eosinophils ( < 150/μL), there were no differences in symptom severity, control status or lung function parameters. Conclusion These findings suggest that blood eosinophil count ≥ 300/μL may identify asthma patients at higher risk for severity and heightened eosinophil activity, supporting its utility as a biomarker in a real clinical setting.