Risk factors influencing bronchial hyperresponsiveness to methacholine in school age and adolescence of atopic dermatitis

PURPOSE: Many studies have shown the importance for bronchial hyperresponsiveness (BHR) in children with bronchial asthma and allergic rhinitis. However, studies have not been done in BHR in school age and adolescence with atopic dermatitis (AD). METHODS: The patients with history of bronchial asthma were excluded and methacholine challenge test (MCT) was performed in 103 children with atopic dermatitis. The positive of MCT result is defined as provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second (PC20)< or =8 mg/mL. According of the level of PC20, the patients were divided into two groups. RESULTS: The group 1 (BHR+) was observed in 43 of all patients (41.7%). Of two groups, significant differences were observed in age, body mass index. No significant differences were observed in the number of male, SCORing Atopic Dermatitis (SCORAD) index, admission history, smoking exposure history, other allergic disease, parental allergic disease. The group 1 (BHR+) have higher levels of total eosinophil count compared with the group 2 (BHR-) (629.8+/-360.5/microL vs. 470.2+/-253.9/microL, P=0.01). But no significant association was found between severity of BHR and SCORAD score, total immunoglobulin E, total eosin ophil count and eosinophil cationic protein (r=0.008, P=0.961; r=-0.217, P=0.162; r=0.225, P=0.147; r=-0.032, P=0.841). The list of allergen is that the house dust mite, tree, weed, food, animal hair, and fungus. The house dust mite has correlation with bronchial hypersensitivity statistically and the any of allergen groups, either. CONCLUSION: No significant relationship was observed between degree of BHR and allergy laboratory finding, severity of AD.

Crucial Factors for Bronchial Hyperresponsiveness in Children with Mild Asthma / 소아알레르기및호흡기학회지

PURPOSE: Bronchial hyperresponsiveness (BHR) is one of the key components of childhood asthma phenotype. Patients with mild asthma may have coexisting severe BHR, although the reasons for this are uncertain. The factors of any relationship between BHR has been identified as a central issue in our understanding of asthma. METHODS: To investigate the factors that determine the presence of BHR in mild childhood asthmatics, 62 children (49 boys and 13 girls) with mild asthma were studied. Patients were characterized by skin prick tests, spirometry and bronchial challenge with methacholine. BHR to methacholine was expressed as the provocative methacholine concentration causing a 20 percent fall in FEV1 (PC20), PC20 value of 8 mg/mL was used as a cut-off for defining a BHR to methacholine. RESULTS: This cohort of 62 children with mild asthma was classified into two groups according to the results of methacholine challenge test (MCT). A positive MCT group was obtained for 33 subjects (53.2 percent). The proportion of children sensitized to house-dust mites (HDM) was significantly higher in the MCT-positive group than the negative one. Results showed a, a positive rate of skin prick test: 47% vs. 23% (P< 0.05) and HDM-specific IgE: 68% vs. 43% (P< 0.05). CONCLUSION: Asthmatics with positive MCT were clearly accompanied by increased sensitization to house-dust mites and reduced small airway calibers. Therefore, sensitization to common aeroallergens and changed small airway calibers might be crucial factors in the successful management of asthma.

Nasal Hyperreactivity to Methacholine Test in Perennial Allergic Rhinitis

Although histamine and methacholine challenge tests are commonly used to evaluate the hypersensitivity in allergic rhinitis, some controversies still remain to standardize the test. This study was designed to evaluate the usefulness of the methacholine challenge test for the evaluation of hyperreactivity in allergic rhinitis. Twenty three patients with perennial allergic rhinitis and 17 normal subjects were included in this study. All subjects underwent saline nasal challenge and methacholine nasal challenge test with different doses (6 mg, 12 mg, 24 mg / in 0.5 ml of saline). We measured the nasal cavity volume by acoustic rhinometry in each step and counted the number of sneezes for 15 minutes. The volume of nasal secretion was also measured by tissue paper method. Besides that, we compared the data between allergic patients with a short (under 1 year) and long duration (more than 1 year). There were no differences in the frequency of sneezing and nasal volume change to each amount of methacholine in both groups. Nasal secretion increased after methacholine challenge in both groups. However, the allergic group showed significant increase after the methacholine challenge of 12 mg compared to the control group. And the volume of nasal secretion significantly increased in patients with a long duration. The nasal methacholine challenge test can be used as a diagnostic tool to detect hyperreactivity in perennial allergic rhintis. The optimal dilution was 12 mg (in 0.5 ml of saline) for the nasal methacholine challenge test.

Nasal Hyperreactivity to Methacholine Test in Perennial Allergic Rhinitis

Although histamine and methacholine challenge tests are commonly used to evaluate the hypersensitivity in allergic rhinitis, some controversies still remain to standardize the test. This study was designed to evaluate the usefulness of the methacholine challenge test for the evaluation of hyperreactivity in allergic rhinitis. Twenty three patients with perennial allergic rhinitis and 17 normal subjects were included in this study. All subjects underwent saline nasal challenge and methacholine nasal challenge test with different doses (6 mg, 12 mg, 24 mg / in 0.5 ml of saline). We measured the nasal cavity volume by acoustic rhinometry in each step and counted the number of sneezes for 15 minutes. The volume of nasal secretion was also measured by tissue paper method. Besides that, we compared the data between allergic patients with a short (under 1 year) and long duration (more than 1 year). There were no differences in the frequency of sneezing and nasal volume change to each amount of methacholine in both groups. Nasal secretion increased after methacholine challenge in both groups. However, the allergic group showed significant increase after the methacholine challenge of 12 mg compared to the control group. And the volume of nasal secretion significantly increased in patients with a long duration. The nasal methacholine challenge test can be used as a diagnostic tool to detect hyperreactivity in perennial allergic rhintis. The optimal dilution was 12 mg (in 0.5 ml of saline) for the nasal methacholine challenge test.

Effect of Vitamin C on Airway Hyperresponsiveness in Heavy Smokers / 결핵

BACKGROUND: Vitamin C has been reported to have a role in the decrease of airway hyperresponsiveness in animal models. This data is based on some metabolic actions of vitamin C, such as promotion of histamine degradation, producing mote PGE2 than PGE2 alpha in cyclooxygenase pathway, decrease of smooth muscle contraction, and acting as reducing agent of oxidant. It has been also known that heavy smokers have lower blood levels of vitamin C than nonsmokers and this deficiency in heavy smokers have been explained by several mechanisms, such as increased oxidation by oxidants and free radicals, increased biosynthesis of catecholamine and serotorim released by nicotine, and inadequate dietary intake. In this study, We attempted to assess effect of vitamin C on bronchial hyperresponsiveness in heavy smokers who have bronchial hyerresponsiveness and role of vitamin C on bronchial hyperresponsiveness. METHOD: To assess acute effect of vitamin C on airway hyperresponsiveness, blood sample for vitamin C level and spirometry, methacholine challenge test were done in 17 smokers and 8 nonsmokers, and one hour after oral administration of vitamin C 3 g, blood sample for vitamin C level and spirometry, metliacholine challenge test were repeated. To assess chronic effect of vitamin C on airway hyperreeponsiveness after daily administration of vitamin C 1 g for one week in 17 smokers, blood sample for vitamin C level and spirometry, methacholirie challenge test were done. To assess role of vitamin C, after oral administration of vitamin C 3 g plus indomethacin 100 mg in 12 of 15 smokers who were reactive to methacholine challenge test, spirometry and methacholine challenge test were done and after oral intake of indomethacin 100 mg in 12 smokers who were reactive to methacholine challenge test, spirometry and metbachoine challenge test were repeated. RESULT: There were no significant differences in whole blood vitamin C levels between smokers(1.17+/-0.22mg/dL) and nonsinokers(1.14+/-0.19 mg/dL) (p>0.05). Fifteen of the 17 smokers(88.2%) were reactive to metbacholine chaflenge test amd 10 of the 15 smokers who were reactive to methacholine challenge test were less than 8 mg/dL in PC20FEV1, and 7 of the 8 nonsmokers(87.5%) were nonreactive to methacltoline challenge test There were significant decrease in bronchial responsiveness after oral administration of xitamin C 3 g in 13 of the 15 smokers who were reactive to methachoine challenge test. This significant decrease persisted with maintenance daily administration of 1 g for one week. PC20FEV1 were not correlated to vitamin C levels in smokers. After oral administration of indomethacin 100 mg, significant reduction of bronchial responsiveness that occured after oral administration of xdtamin C 3 g in smokers were attenuated. CONCLUISON: Although there were no significant differences in whole blood vitamin C levels between smokers and nonsmokers, heavy smokers have significant increase in bronchial responsiveness than nonsmokers. This bronchial hyperresponsiveness of heavy smokers can be attenuated by vitamin C supplement Disappearance of vitamin C effect by indcrnethaein supplement may suggest that vitamin C exert its effect via alteration of arachidonic acid metabolism.

Bronchial Hyperresponsiveness in Workers Exposed to Isocyanates / 예방의학회지

We studied the association of nonspecific bronchial hyperresponsiveness with general characteristics, exposure concentration, respiratory symptoms, chest x-ray findings, past histories and pulmonary function. We determined bronchial hyperresponsiveness by methacholine challenge test. And we conducted a respiratory symptom questionnaire and performed spirometry on 111 workers occupationally exposed to isocyanates in various industries. About 21.6% of subjects had bronchial hyperresponsiveness. No significant differences were observed between the hyperresponsive and non-responsive group with respect to age, sex, employment period, height, and smoking histories cough and breathlessness were significantly associated with the bronchial hyperresponsiveness. The hyperresponsive group had more experience of bronchitis and asthma in the past than the non-responsive group. The lower FEV1 and FEV1 % were closely related with bronchial hyperresponsiveness. Bronchial hyperrespoosiveness seems to be associated with some of respiratory symptoms, past histories and pulmonary function parameters in workers exposed to isocyanates.