Annals of allergy最新文献

The homes of asthmatic patients and nonasthmatic control group who worked on or lived near an irrigated farm were sampled over a 3-month period. Of a total of 21 genera isolated, 17 were from the indoor air in the patients' homes, 10 from the homes of the control group, and 18 from the air over the farm. Penicillium and Aspergillus species were dominant in the indoor spora while Gliocladium and Curvularia species were most common on the farm. There was significant correlation between the airborne genera encountered in the homes of patients and the farm sites.

Background: The influence of an allergen challenge on recumbency induced changes in airway responsiveness to methacholine was documented in seven nonsmoking subjects with stable mild asthma (3M, 4F).

Methods: All subjects spent four hours (8 to 12 AM) in the supine position before and 24 hours after an allergen challenge that induced a dual asthmatic response. FEV1 was measured hourly in the supine position and a methacholine challenge was done in the sitting position before and after each 4-hour period. None used bronchial antiinflammatory drugs before or during the study.

Results: The mean maximal fall in FEV1 (+/- SEM) was 31.0 +/- 1.1% within one hour of the last allergen inhalation and 27.5 +/- 4.9% between two and eight hours later. Presupine/postsupine session FEV1 (%pred +/- SEM) was unchanged either at baseline or postallergen challenge sessions, with values of 89.3 +/- 2.7/88.3 +/- 5.1 and 86.6 +/- 4.2/87.4 +/- 5.7. Presupine/postsupine PC20 methacholine was slightly reduced but this did not reach statistical significance (P > .05), with a mean PC20 (mg/mL) of 0.83 +/- 1.44/0.52 +/- 1.46 (preallergen session); 0.55 +/- 1.44/0.39 +/- 1.37 (postallergen challenge session). This delta PC20 (baseline/post-session) did not differ between the two sessions (P > .05). The delta PC20 was not correlated with the magnitude of the late asthmatic response to allergen nor the postallergen increase in airway responsiveness.

Conclusions: We conclude that an acute allergen challenge does not significantly increase recumbency-induced changes in airway response to methacholine in patients with mild asthma. The possibility of a significant influence of pro-inflammatory stimuli on recumbency-induced changes in bronchomotor tone in more severe patients or if the stimulus is repeated should be further assessed.

Background: Rates of death from asthma in the United States have increased progressively since 1978.

Objective: To identify recent trends in asthma mortality.

Methods: The National Center for Health Statistics supplied asthma mortality data (ICD 493), and the Bureau of the Census supplied population data that permitted calculation and graphing of mortality data by age group, race, sex, and region and calculation and tabulation of mortality rates by state. The Departments of Health and Vital Statistics of Australia, Canada, Great Britain, and New Zealand provided data that permitted calculation and graphing of rates of death from asthma (ICD 493) in those countries.

Results: Rates of death from asthma in the United States increased from 0.8 per 100,000 in 1977 and 1978 to 2.0 in 1989, fell to 1.9 in 1990 and then increased again to 2.0 in 1991. Rates have been much higher for blacks than whites; age-adjusted rates for blacks increased from 1.5 in 1977 and 1978 to 3.5 in 1991; those for whites, from 0.5 in 1977 to 1.2 in 1991. Rates of death from asthma have increased with age and across time have increased in almost all age groups. The greatest proportional increase has occurred at 10 to 14 years of age with rates of 0.1 in 1979, 0.5 in 1987, and 0.4 in 1991. Rates of death at 5 through 34 years of age have increased for both blacks and whites in all regions of the country. Increases in rates of death from asthma have also occurred in other countries, but rates have been falling in New Zealand since the peak of 8.1 in 1980 and in Australia since the peak of 5.7 in 1989.

Conclusions: The recent plateau in increases in rates of death from asthma in the United States may suggest effectiveness of improved management of asthma that may have followed increased awareness of the importance of optimal management.

Thirty-seven asymptomatic ragweed-sensitive patients and ten controls were challenged both epicutaneously and intranasally with ragweed. Clinical assessments of both early (20 minutes) and late (six hours) phase reactions of skin (mm) and nose (clinical score) were performed. A positive routine nasal challenge was defined as a clinical score 5 (0-12). Augmented nasal challenges were 10-fold higher than routine for each patient. Nasal lavage was performed at baseline, after positive challenge, one, two, and six hours postchallenge. Mediators assayed included histamine, eosinophil cationic protein (ECP), leukotrine C4 (LTC4), and prostaglandin D2 (PGD2). All 37 patients had an early skin reaction. Only 28/37 had a late response correlating with the early. Twenty-one patients had routine nasal challenges; 14 then volunteered for an augmented challenge. The remaining 16 had augmented challenges only. All had a nasal clinical early response, but late responses were infrequent (9). The early phase PGD2 was higher in augmented compared with routine challenges (P < .05) as were the late histamine (P < .05) and ECP (P < .05). The early skin test correlated with early LTC4 (P < .001) and PGD2 (P < .05). The early and late LTC4 (P < .05) and PGD2 (P < .01) were also related. In summary, late phase reactions of both the nose and skin are related to the intensity of the early response.

Objective: The information presented will aid the practicing allergist in the recognition and management of pediatric-onset mastocytosis.

Data sources: Index Medicus from 1985 to present with keywords: mastocytosis; pediatrics; cutaneous. Limited to English language and to human disease.

Study selection: Information relative to mastocytosis in the pediatric age group to adulthood was reviewed.

Results: Mastocytosis in children is an uncommon disease and is characterized by mast cell hyperplasia and release of mast cell mediators, particularly in the skin. It generally presents during the first 2 years of life. The most common manifestation is a solitary mastocytoma, with urticaria pigmentosa being the next most frequent manifestation. The most common initial presenting symptom of pediatric mastocytosis is pruritus. Complications of severe mastocytosis include formation of bullae and gastrointestinal bleeding attributed to high levels of circulating plasma histamine, which in turn stimulates gastric acid secretion.

Conclusion: Treatment of pediatric mastocytosis is largely symptomatic. Prognosis seems to be somewhat related to the severity of the disease, with children with less extensive skin involvement tending to have the best chance to have resolution of the disease by adulthood.

Nonspecific bronchial provocation testing is clinically useful in the evaluation of patients with symptoms suggestive of asthma. Testing is usually reserved for those with normal or near normal baseline spirometry. Although bronchial provocation testing is safe and widely available, the protocol is time consuming and not without expense. It has been reported that a reduced FEF25-75% in the context of an otherwise normal spirogram suggests that asthma should be considered. To evaluate this suggestion, we compared the baseline FEF25-75% (expressed as percent of predicted) with the results of the subsequent methacholine bronchial provocation test in 205 consecutive patients referred for testing. The mean baseline FEF25-75% in the 112 patients with normally responsive airways (ie, a negative bronchial provocation test) was 95.4 +/- 27.5%. In the 93 patients with a positive bronchial provocation test, the mean FEF25-75% was 77.6 +/- 27.2%. The mean FEF25-75% in those with hyperresponsive airways was significantly lower (t = 4.616, P < .0001). Of those patients with a positive bronchial provocation test, there was no significant correlation, however, between the baseline FEF25-75% and the degree of bronchial hyperresponsiveness as assessed by the PC20FEV1 (r = .154, P = .141). When a significant reduction in FEF25-75% was defined as less than 60% of predicted, the sensitivity of the prediction rule was 25.8%, the specificity was 92.0%, the positive predictive value was 72.7%, and the negative predictive value was 60.0%. From these results, we conclude that the FEF25-75% derived from simple spirometry may be useful in predicting the presence or absence, but not the degree, of bronchial hyperresponsiveness.

The efficacy of loratadine as prophylactic therapy for seasonal allergic rhinitis was evaluated in a randomized, double-blind, parallel group, placebo-controlled study. One hundred eighteen subjects received either loratadine, 10 mg once daily, or placebo for 6 weeks. Treatment was begun prior to the onset of grass pollen seasonal symptoms of allergic rhinitis. Total symptom-free days occurred more frequently in subjects receiving loratadine. More loratadine than placebo subjects (65% versus 49%) had no symptoms or mild rhinitis at the end of the study. In contrast, the differences between loratadine and placebo in symptom scores did not achieve significance. The incidence of sedation and anticholinergic effects were comparable between the groups. Prophylactic loratadine therapy was effective in suppressing symptoms of seasonal allergic rhinitis and providing patients with symptom-free days throughout the pollen season.