Atopic dermatitis (AD) is a chronically relapsing inflammatory disorder of the skin. It is characterized by severe pruritus, sleep disturbance, and poor quality of life. In addition, AD frequently occurs in childhood and is considered the first manifestation of atopic march, which progresses into respiratory allergic diseases, such as asthma and allergic rhinitis, as the patient grow older. In this regard, the early diagnosis and active treatment of AD are required to lower the severity of disease and to prevent the development of atopic march. The proper management of AD includes avoidance of aggravating factors, barrier repair by skin care, and control of inflammation and infection with appropriate medications. Among them, identification and elimination of environmental risk factors responsible for worsening skin symptoms are essential. They include temperature, humidity, food and inhalant allergens, microorganisms, air pollutants, ultraviolet radiation, water hardness, and so forth. In particular, there is growing concern about indoor environment because time spent indoors and exposure to various kinds of pollutants is increasing with modernization and industrialization. In this review, we summarize the hazardous effect of temperature, humidity, cigarette smoke, volatile organic compounds, formaldehyde, and phthalates on the development or aggravation of AD. Current epidemiological studies and animal experiments suggest possible contributions of various indoor environmental factors to the development and aggravation of AD. However, further studies are needed to demonstrate a causal relationship between indoor environmental factors and AD. (Allergy Asthma Respir Dis 2020;8:175-183)

Purpose: Veterinary clinic workers are frequently exposed to various animal allergens, increasing the possibility of occupational allergy. However, allergic symptoms in this group have not been studied extensively. We aim to investigate the prevalence of allergic symptoms and especially occupational allergic diseases in veterinary clinic workers.
Methods: A questionnaire-based cross-sectional study was conducted. The questionnaire for allergic symptoms was sent to the veterinary clinic workers in the Gyeongsangnam-do region and was collected for statistical analysis. Occupational asthma, rhinitis, or dermatitis were defined as the new onset or worsening of each symptom at work and improvement in the condition while away from the work.
Results: Ninety-five veterinary clinic workers participated in this study; 33.7% were male and their mean age was 33.7 years. Fifty-two subjects (54.7%) experienced conjunctivitis symptoms along with rhinitis symptoms. Fifty-seven subjects (60.0%) experienced rhinitis symptoms, but not cold or flu, and 40% of the subjects were suspected of having occupational rhinitis. Forty subjects reported that they had lower respiratory symptoms, while 11 (11.6%) and 4 subjects (4.2%) had asthma and occupational asthma, respectively. Twenty-two subjects with respiratory symptoms complained of symptom worsening upon contact with animals, especially cats. Of 95 subjects, 31 had skin itching, 11 reported skin rash, and 6 had occupational dermatitis. There was no significant difference in the type of work performed by the study participants.
Conclusion: This study is the first to analyze the prevalence of allergic symptoms in veterinary clinic workers in Korea. The data can be employed for the prevention of occupational allergic diseases in veterinary clinic workers and can provide a basis for further studies. (Allergy Asthma Respir Dis 2020;8:184-190)

Purpose: Both allergic rhinitis and asthma are considered one airway disease, which interacts with each other in disease onset and symptom worsening. We evaluated factors developing new or persistent asthma symptoms in elementary school children with allergic rhinitis.
Methods: We selected 343 children aged 6 to 7 years who had rhinitis symptoms within 12 months and allergic sensitization on skin prick tests among 2,491 elementary school children. The questionnaires on symptoms, medical history and environments, blood eosinophils, serum total IgE, pulmonary function test, and bronchial provocation tests were obtained. Using multiple regression analysis, we evaluated factors for later asthma symptoms during a follow-up period of 4 years.
Results: The independent risk factors for later asthma symptoms among children with allergic rhinitis were higher body mass index (adjusted odds ratio [aOR], 1.29; 95% confidence interval [CI], 1.06-1.56; P=0.012), a parental diagnosis of asthma (aOR, 6.19; 95% CI, 1.59-24.06; P=0.008), residence in the rural area (aOR, 5.37; 95% CI, 1.34-21.42; P=0.017), and a history of bronchiolitis in the first 2 years (aOR, 5.82; 95% CI, 1.42-23.80; P=0.014). However, pulmonary functions, the levels of bronchial hyper-responsiveness, and the patterns of sensitization showed not significant factors. Children whose allergic rhinitis was treated in the follow-up period were less likely to have asthma symptoms later (aOR, 0.30; 95% CI, 0.10-0.93; P=0.036).
Conclusion: In the school-aged children with allergic rhinitis, body mass index and asthma-related risk factors are crucial for developing asthma symptoms. The appropriate treatment of rhinitis may decrease asthma symptoms. (Allergy Asthma Respir Dis 2020;8:191-198)

Purpose: The threshold levels for symptom development of pollinosis vary among studies and countries. This study aimed to determine currently used threshold levels for it.
Methods: Oak, pine, Japanese hop, and ragweed pollen samples were collected daily for 8 years from the Seoul and Guri areas. A total of 792 subjects with allergy to these pollens were recruited. The symptom index (SI) was assessed through telephone interviews and allergy questionnaires, and data were analyzed using decision tree.
Results: The risk index for oak pollen allergy was “mild” when the pollen count was 0-2 grains/m3, “moderate” when it was 3-11 grains/m3, “severe” when it was 12-28 grains/m3, and “dangerous” when it was ≥29 grains/m3. The risk level for pine pollen allergy was “mild” when the pollen count was 0-4 grains/m3, “moderate” when it was 5-42 grains/m3, “severe” when it was 43-66 grains/m3, and “dangerous” when it was ≥67 grains/m3. For Japanese hop pollen allergy, the risk level was “mild” when the pollen count was 0-8 grains/m3, “moderate” when it was 9-10 grains/m3, “severe” when it was 11-19 grains/m3, and “dangerous” when it was ≥20 grains/m3. Finally, for ragweed, the risk level was “mild” when the pollen count was 0-1 grains/m3, “moderate” when it was 2-6 grains/m3, “severe” when it was 7-33 grains/m3, and “dangerous” when it was ≥34 grains/m3.
Conclusions: Revising the threshold levels for the risk index for pollen allergies may be useful for developing pollen prediction models for patients with pollen allergies in Korea. (Allergy Asthma Respir Dis 2020;8:199-205)

Purpose: Pulmonary underdevelopment is one of the pulmonary causes of neonatal mortality, which is categorized into pulmonary agenesis, pulmonary aplasia, and pulmonary hypoplasia. Congenital diaphragmatic hernia is a well-known cause of pulmonary hypoplasia; however, further studies are needed for other etiologies. Patients with pulmonary underdevelopment show varying degrees of clinical severity. Most patients with pulmonary underdevelopment have respiratory distress at birth, while a few have only mild symptoms. Our study investigated the natural course and prognosis of pulmonary underdevelopment by analyzing multiple cases from a single tertiary medical center.
Methods: A retrospective review was conducted on patients diagnosed with pulmonary hypoplasia and agenesis from January 2000 to August 2019. Cases were extracted from the clinical database of Seoul National University Children's Hospital by searching for keywords related to pulmonary underdevelopment.
Results: A total of 28 patients were identified. Four patients had pulmonary agenesis, and all were idiopathic. Twenty-four patients had evidence of pulmonary hypoplasia with diverse causes. The median age at diagnosis was 11.5 days (range, 1-240 days) and the mean gestational age was 35 weeks 2 days±3 weeks 6 days. Twenty patients received ventilator care and 11 had various degrees of pulmonary hypertension. The long-term survival rate was 50%. The median age of death among pulmonary hypoplasia patients were 11 days (range, 1-730 days). All patients without ventilator care survived. The incidence of ventilator care, pneumothorax, and pulmonary hypertension were significantly higher among patients who died.
Conclusion: The prognosis of pulmonary underdevelopment depends on the severity of respiratory distress and pulmonary hypertension in earlier life. Patients with severe distress appear to have severe degree of pulmonary hypoplasia. Patients without ventilator support in the neonatal period survived without significant morbidities. (Allergy Asthma Respir Dis 2020;8:206-212)

Purpose: Respiratory syncytial virus (RSV) is one of the most common causes of respiratory tract infections, especially in patients aged <3 years. There are 2 antigenically different RSV subtypes, A and B. This study aimed to assess if the RSV subtype is independently associated with increased disease severity.
Methods: We retrospectively collected data from the medical records of children hospitalized with RSV infection, aged < 3 years at Dong-A University Hospital between September, 2014 and December, 2018.
Results: RSV A and RSV B infections were observed in 111 and 66 cases, respectively. Pneumonia was most commonly observed, followed by bronchiolitis in both subtypes. There were no significant differences between the groups regarding birth weight, gestational age, and incidence of having siblings. The duration of admission, duration of fever, and severity index were similar between the groups. The incidence of high fever ( >39°C) was slightly higher in the RSV B group (13.6%) than in the RSV A group (11.7%), although the difference was not statistically significant. Laboratory findings, including the neutrophil-lymphocyte ratio, were similar between the groups. The incidence of systemic steroid therapy was higher in the RSV A group (12.6%) than in the RSV B (3.0%) group (P=0.03). Patients aged <12 months, the incidences of oxygen therapy (P=0.03) and systemic steroid therapy (P=0.04) were higher in the RSV A group, suggesting that patients aged <12 months with RSV A infection may have clinically more severe disease.
Conclusion: We recommend intensive monitoring if RSV A infection is detected in young children under 12 months. (Allergy Asthma Respir Dis 2020;8:213-219)

Purpose: Induced sputum eosinophil count is useful for the evaluation and diagnosis of asthma and eosinophilic bronchitis (EB). The aim of this study was to evaluate the correlation of induced sputum eosinophil count with various allergic indicators, including the peripheral blood eosinophil count, in pediatric asthma and EB.
Methods: From May 2014 to July 2018, 126 children visited Kyungpook National University Children's Hospital, and underwent methacholine bronchial challenge test and sputum induction. Peripheral blood eosinophil counts, serum eosinophil cationic protein (ECP), serum total IgE, immunoCAP for inhalant allergens, and skin prick test were performed in the study subjects.
Results: In the asthma group, the eosinophil count of induced sputum correlated with peripheral blood eosinophils (r=0.279, P=0.043). The concordance rates of sputum and peripheral blood eosinophil count in the asthma and EB groups were 64.1% and 25.7%, respectively. The number of eosinophils in the sputum also correlated with serum total IgE, ECP, and specific IgE to Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Aspergillus in the asthma group.
Conclusion: The number of eosinophils in the induced sputum correlated with peripheral blood in the asthma group. However, a third of subjects were discordant. Therefore, we need to keep in mind the possibility of discordance when predicting the degree of airway eosinophilic inflammation using the peripheral blood eosinophils. In EB, the number of induced sputum eosinophils did not correlate with the number of peripheral blood eosinophils, which may be attributed to the difference in mechanism. Further studies are warranted. (Allergy Asthma Respir Dis 2020;8:220-226)

Bee pollen is a mixture of pollen, nectar collected by honeybees, and digestive enzymes secreted from honeybees, which is consumed as a dietary supplement. We experienced a case of anaphylaxis after ingestion of bee pollen in a patient with seasonal allergic rhinitis and oral allergy syndrome caused by watermelons, Korean melons, peaches, and plums. The skin prick test was positive for bee pollen, dandelion, ragweed, and mugwort, and specific IgE to honeybee venom was negative. According to the literature, bee pollen causing systemic allergic reactions mainly consists of the plant family Compositae, including dandelion, ragweed, and mugwort. Thus, ingestion of bee pollen should be closely monitored in patients with allergic rhinitis worsening in autumn, especially those with oral allergy syndrome for foods that cross-react with weed pollen. (Allergy Asthma Respir Dis 2020;8:227-230)

Nontuberculous mycobacterial (NTM) pulmonary disease generally occurs in old people with underlying lung disease. However, unlike adults, NTM infections in children with normal immunity are rare, and they occasionally manifest as lymphadenitis. We herein present a rare case of NTM pulmonary disease in a girl who is the youngest patient reported in Korea. A 16-year-old female was brought to the hospital because of dyspnea on exertion, fever, and productive cough. The patient had bronchiectasis. She underwent Fontan operation for right isomerism, double outlet right ventricle, pulmonary stenosis, and had been taking prophylactic antibiotics for asplenia. NTM were found in the sputum and bronchoalveolar lavage fluid by acid fast bacillus (AFB) staining and culture, which were identified as Mycobacterium avium. The treatment started with azithromycin, ethambutol and rifampicin. After 6 months of treatment, respiratory symptoms improved and the sputum AFB culture became negative. She is currently on medication with above-mentioned drugs for 10 months without any adverse effects. This case suggests that NTM pulmonary disease should be suspected and properly treated especially in children and adolescents with underlying lung disease. (Allergy Asthma Respir Dis 2020;8:231-236)