Moderate symptom-based exacerbations as predictors of severe claims-based exacerbations in asthma.

OBJECTIVES: Asthma exacerbations have well-established clinical and economic impact, yet lack consensus on characterization of an episode's severity. Asthma treatment guidelines outline the concept of a moderate asthma exacerbation; however, a clear definition that can be operationalized has not been proposed, METHODS: Adult asthma (ICD-9: 493.XX) patients, with at least 9 months of continuous enrolment in the Fallon Community Health Plan were included in the retrospective cohort study. Patients diagnosed with Chronic Obstructive Pulmonary Disease (COPD) or other lower respiratory tract conditions were excluded. The first reported asthma-related event following a 2-week symptom-free period was designated as the index event. Asthma-related events were categorized as (1) moderate exacerbations (symptom-based) or (2) severe exacerbations (claims-based). Timing between and temporal sequence of asthma-related events along with average costs were calculated, RESULTS: Of 3126 eligible patients, 55% reported an asthma-related event followed by a recurrent event(s). Moderate exacerbations followed by recurrent moderate exacerbations were most frequent (20%) with the shortest interval between exacerbations (mean: 83 days [SD 87]). Moderate exacerbations followed by severe exacerbations occurred in 16% of patients with an average of 176.74 (SD 176.94) days between events, CONCLUSIONS: Patient report of asthma bothersome enough to initiate contact with a clinician, but not requiring oral corticosteroid (OCS), is a definition for a moderate exacerbation that can be operationalized for research purposes. Further work is needed to demonstrate whether identification of moderate exacerbations will allow interventions that impact the frequency and timing of future exacerbations.

Pest and allergen exposure and abatement in inner-city asthma: a work group report of the American Academy of Allergy, Asthma & Immunology Indoor Allergy/Air Pollution Committee.

Our work group report details the importance of pest allergen exposure in inner-city asthma. We will focus specifically on mouse and cockroach exposure. We will discuss how exposure to these pests is common in the inner city and what conditions exist in urban areas that might lead to increased exposure. We will discuss how exposure is associated with allergen sensitization and asthma morbidity. Finally, we will discuss different methods of intervention and the effectiveness of these tactics.

Development of the pediatric environmental health specialty unit network in North America.

Training in environmental health in general, and pediatric environmental health in particular, is inadequate. The Agency for Toxic Substances and Disease Registry began to develop pediatric environmental health specialty units (PEHSUs) after noting the dearth of practitioners who could evaluate and manage children with exposures to environmental health hazards. The Environmental Protection Agency subsequently joined in providing support for what has developed into a network of 13 PEHSUs in North America. PEHSUs provide services to families, act as consultants to clinicians and public agencies, develop educational materials, and respond to natural disasters, including hurricanes and wildfires. PEHSUs are relatively easy to organize and should be replicable internationally.

Health effects of mold in children.

Mold is ubiquitous, and exposure to mold and its products of metabolism is unavoidable, whether indoors or outdoors. Mold can produce a variety of adverse health outcomes by four scientifically validated pathophysiologic mechanisms: hypersensitivity, toxicity, infection, and irritation. Some adverse health outcomes have been attributed to mold for which mechanisms of injury are not well defined or are implausible. This article discusses these adverse health outcomes, focusing predominantly on those for which valid associations have been established.

Association of asthma symptoms with peak particulate air pollution and effect modification by anti-inflammatory medication use.

Maxima of hourly data from outdoor monitors may capture adverse effects of outdoor particulate matter (PM) exposures in asthmatic children better than do 24-hr PM averages, which form the basis of current regulations in the United States. Also, asthmatic children on anti-inflammatory medications may be protected against the proinflammatory effects of air pollutants and aeroallergens. We examined strengths of pollutant associations with asthma symptoms between subgroups of asthmatic children who were on versus not on regularly scheduled anti-inflammatory medications, and tested associations for different particle averaging times. This is a daily panel study of 22 asthmatic children (9-19 years of age) followed March through April 1996 (1,248 person-days). They lived in nonsmoking households in a semirural area of Southern California within the air inversion mixing zone (range, 1,200-2,100 feet) with transported air pollution from urban areas of Southern California. The dependent variable derived from diary ordinal scores is episodes of asthma symptoms that interfered with daily activities. Minimum to 90th-percentile levels of exposures at the outdoor monitoring site were 12-63 microg/m(3) for 1-hr PM < 10 microm in aerodynamic diameter (PM(10)); 8-46 microg/m(3) for 8-hr PM(10); 7-32 microg/m(3) for 24-hr PM(10); 45-88 ppb for 1-hr O(3); 6-26 ppb for 8-hr NO(2); 70-4,714 particles/m(3) for 12-hr daytime fungi; and 12-744 particles/m(3) for 24-hr pollen. Data were analyzed with generalized estimating equations controlling for autocorrelation. There was no confounding by weather, day of week, or linear time trend. Associations were notably stronger in 12 asthmatic children who were not taking anti-inflammatory medications versus 10 subjects who were. Odds ratios (95% confidence intervals) for asthma episodes in relation to lag 0 minimum to 90th-percentile pollutant changes were, respectively, 1-hr maximum PM(10), 1.92 (1.22-3.02) versus 0.96 (0.25-3.69); 8-hr maximum PM(10), 1.68 (0.91-3.09) versus 0.75 (0.18-3.04); 24-hr average PM(10), 1.35 (0.82-2.22) versus 0.80 (0.24-2.69); 1-hr maximum O(3), 1.28 (0.75-2.17) versus 0.76 (0.24-2.44); 8-hr maximum NO(2), 1.91 (1.07-3.39) versus 1.08 (0.30-3.93); 12-hr fungi, 1.89 (1.24-2.89) versus 0.90 (0.35-2.30); 24-hr pollen, 1.90 (0.99-3.67) versus 0.85 (0.18-3.91). Pollutant associations were stronger during respiratory infections in subjects not on anti-inflammatory medications. Although lag 0 1-hr maximum PM(10) showed the strongest association, the most robust associations were for lag 0 and 3-day moving averages (lags 0-2) of 8-hr maximum and 24-hr mean PM(10) in sensitivity analyses testing for thresholds. Most pollutant effects were largely driven by concentrations in the upper quintile. The divergence of exposure-response relationships by anti-inflammatory medication use is consistent with experimental data on inflammatory mechanisms of airborne pollutants and allergens.

A regional comparison of mold spore concentrations outdoors and inside "clean" and "mold contaminated" Southern California buildings.

A total of 625 buildings and outdoor locations in the San Diego, California, area were monitored using the Allergenco Sampl-Air MK-3 impaction sampler or the Zefon Air-O-Cell slit bioaerosol cassette. Locations were classified by rigid criteria as clean commercial, commercial with mold growth, clean residential, residential with water staining, and residential with mold growth. In addition, coastal and inland outdoor locations were measured. Seven categories (total spores, Ascospores/Basidiospores, Cladosporium, Smut/Myxomycetes-like, Aspergillus/Penicillium (AS/PE), Alternaria, and Unidentified/Other) were detected frequently enough that maximum likelihood estimate techniques could be used to determine distribution parameters and, thus, treat these as continuous variables. For total counts (no nondetectables) an analysis of variance was used to examine differences in location means. For the other categories Land's confidence limits were generated and visually compared for differences among locations. For 12 other categories (Curvularia, Dreschlera, Epicoccum, Fusarium, Mildew-like, Pithomyces, Rusts, Stachybotrys, Stemphyllium, Torula, Ulocladium, and Zygomycetes-like), detection generally occurred in less than 10% of samples. These genera were treated as dichotomous (detect/nondetect) data, and Chi-square analyses differentiated between locations. For total counts, values were significantly different on the order of clean < outdoor < moldy. There was a large difference between the moldy and other location classes. For AS/PE, moldy location means were clearly higher than those for clean buildings and outdoors, although the clean and outdoor means could not be differentiated. For all other genera the results tend to indicate little or no ability to discriminate location. For example, there were no differences in the probabilities of detecting Stachybotrys among the various locations. In our study only total counts, usually driven by AS/PE concentrations, had value in determining whether a building is mold contaminated employing our set of rigorous location classification criteria.

Clinical use of immunoassays in assessing exposure to fungi and potential health effects related to fungal exposure.

OBJECTIVE: To review and summarize current evidence regarding the proper role of immunoassays in clinical assessments of exposure to fungi and health effects related to fungal exposure. DATA SOURCES: We reviewed relevant scientific investigations and previously published reviews concerning this topic. STUDY SELECTION: The authors' clinical, laboratory, and public health experiences were used to evaluate relevant data for scientific merit. RESULTS: Testing to determine the presence of IgE to specific fungi may be a useful component of a complete clinical evaluation in the diagnosis of illnesses that can be caused by immediate hypersensitivity such as allergic rhinitis and asthma. Detection of IgG to specific fungi has been used as a marker of exposure to agents that may cause illnesses such as hypersensitivity pneumonitis. However, the ubiquitous nature of many fungi and the lack of specificity of fungal antigens limit the usefulness of these types of tests in the evaluation of potential building-related illness and fungal exposure. Specific serologic tests (such as tests for cryptococcal antigen, coccidioidal antibody, and Histoplasma antigen) have been shown to be useful in the diagnosis of some fungal infections, but these are the exception not the rule. CONCLUSIONS: There is currently not enough scientific evidence to support the routine clinical use of immunoassays as a primary means of assessing environmental fungal exposure or health effects related to fungal exposure. Health care providers who care for persons expressing concerns about the relationship of symptoms to potential exposure to fungi are advised to use immunoassay results with care and only as an adjunct to a comprehensive approach to patient care.