Combined effects of prenatal medication use and delivery type are associated with eczema at age 2 years

BACKGROUND

Separately, prenatal antibiotics and Caesarian delivery have been found to be associated with increased risk of allergic diseases. It is not clear whether these factors may modify the effect of each other.

OBJECTIVE

To assess whether the associations between delivery types and eczema, sensitization and total IgE at age 2 years were modified by maternal use of prenatal medications.

METHODS

Prenatal charts of women enrolled in the WHEALS birth cohort were reviewed for delivery mode and medications prescribed and administered throughout their entire pregnancy, including systemic antibiotics and vaginally applied antifungal medications. The associations between the delivery mode and select medications and, eczema, sensitization (≥ 1 of 10 allergen-specific IgE ≥ 0.35 IU/mL) and total IgE at age 2 years were assessed.

RESULTS

There was a lower risk of eczema among vaginally vs. c-section born children (relative risk adjusted for race = aRR = 0.77, 95% CI 0.56, 1.05). Although not statistically significantly different, this association was stronger among the subset of children born vaginally to a mother who did not use systemic antibiotics or vaginal antifungal medications (aRR = 0.69, 95% CI 0.44, 1.08) compared to those born vaginally to mothers who used systemic antibiotics or vaginal antifungals (aRR = 0.81, 95% CI 0.57, 1.14). A protective association between vaginal birth and sensitization (aRR = 0.86, 95% CI 0.72, 1.03) was similar for those children born vaginally to a mother who did not (aRR = 0.87, 95% CI 0.69, 1.10) and who did (RR = 0.85, 95% CI 0.70, 1.04) use systemic antibiotics or vaginal antifungal medications. There were no associations with total IgE.

CONCLUSIONS

Children born vaginally had lower risk of eczema and sensitization compared with those born via c-section; however, the protective association with eczema may be slightly weakened when mothers took systemic antibiotics or vaginally applied medications during pregnancy.

Are cats and dogs the major source of endotoxin in homes?

Previous studies have suggested that exposure to cats and dogs during early childhood reduces the risk of allergic disease, possibly by increasing home endotoxin exposure. This study asked the question of whether cats and dogs are the dominant influence on dust endotoxin concentrations in homes after considering other variables reportedly associated with endotoxin. The presence of cats or dogs in homes, household and home characteristics, and dust endotoxin concentrations from 5 locations were assessed in 966 urban and suburban homes. Whether considered together as pets or as cats and dogs separately, the presence of cats and dogs significantly contributed to living room and bedroom floor endotoxin concentrations, but not to bed endotoxin concentrations. However, the two variables consistently related to endotoxin in all home sites were the home occupant density (occupants/room) and cleanliness of the home. Our data suggest that reducing occupant density and improving home cleanliness would reduce home endotoxin concentrations more than removing pet cats or dogs from the home.

PRACTICAL IMPLICATIONS

Many studies have shown that early childhood exposure to indoor cats or dogs is associated with a reduced risk of later allergic disease and asthma. An important question is whether alteration in allergic risk associated with cat and dog exposure results from increased endotoxin exposure or from some other associated exposure. Our findings show that cats and dogs are not the dominant source of endotoxin in homes; rather, the density of human occupation and poor cleaning contribute more consistently to higher home endotoxin concentrations especially in the beds.

Lifetime dog and cat exposure and dog- and cat-specific sensitization at age 18 years

BACKGROUND

Prior research about whether keeping a dog or cat at home causes allergies to that pet has been limited to outcomes in early childhood.

OBJECTIVE

Evaluate the association between lifetime dog and cat exposure and allergic sensitization to the specific animal at 18 years of age.

METHODS

Participants enrolled in the Detroit Childhood Allergy Study birth cohort during 1987-1989 were contacted at the age 18 years. Sensitization to dog or cat was defined as animal-specific IgE ≥ 0.35 kU/L. Annual interview data from childhood and follow-up interviews at age 18 years were used to determine lifetime indoor dog and cat exposure (indoor was defined when the animal spent >50% of their time inside the house). Exposure was considered in various ways: first year, age groups and cumulative lifetime. Analyses were conducted separately for dogs and cats.

RESULTS

Among males, those with an indoor dog during the first year of life had half the risk [relative risk (RR)=0.50, 95% confidence interval (CI) 0.27, 0.92] of being sensitized to dogs at age 18 compared with those who did not have an indoor dog in the first year. This was also true for males and females born via c-section (RR=0.33, 95% CI 0.07, 0.97). Overall, teens with an indoor cat in the first year of life had a decreased risk (RR=0.52, 95% CI 0.31, 0.90) of being sensitized to cats. Neither cumulative exposure nor exposure at any other particular age was associated with either outcome.

CONCLUSIONS AND CLINICAL RELEVANCE

The first year of life is the critical period during childhood when indoor exposure to dogs or cats influences sensitization to these animals.

Factors associated with nonresponse to a computer-tailored asthma management program for urban adolescents with asthma

BACKGROUND

The ability to identify potentially resistant participants early in the course of an intervention could inform development of strategies for behavior change and improve program effectiveness.

OBJECTIVE

The objective of this analysis was to identify factors related to nonresponse (i.e., lack of behavior change) to an asthma management intervention for urban teenagers. The intervention targeted several behaviors, including medication adherence, having a rescue inhaler nearby, and smoking.

METHODS

A discriminate analysis was conducted using data from a randomized trial of the intervention. Included in this analysis are participants who reported a physician diagnosis of asthma, completed a baseline questionnaire, were randomized to the treatment group, completed >or=2 of 4 educational sessions, and completed >or=2 of 3 follow-up questionnaires. Ninety students met criteria for inclusion in this subgroup analysis.

RESULTS

In logistic regression models for medication adherence, nonresponse was related to low baseline asthma self-regulation, odds ratio = 3.6 (95% confidence interval = 1.3-9.5). In models for having an inhaler nearby, nonresponse was related to low baseline self-regulation and to rebelliousness, OR = 4.7 (1.6-13.2) and 5.6 (1.7-18.0), respectively. Nonresponse to smoking messages was related to rebelliousness, low emotional support, and low religiosity, ORs = 7.6 (1.8-32.3), 9.5 (1.4-63.5), and 6.6 (1.5-29.8) respectively.

CONCLUSIONS

Certain variables had the ability to discriminate the likelihood of response from that of nonresponse to an asthma program for urban, African American adolescents with asthma. These variables can be used to identify resistant subgroups early in the intervention, allowing the application of specialized strategies through tailoring. These types of analyses can inform behavioral interventions.

Gender differences in the association of overweight and asthma morbidity among urban adolescents with asthma

Asthma and obesity disproportionately affect US African-American youth. Among youth with asthma, obesity has been associated with poor control. The impact of gender on this association is unclear. We examined these relationships in a sample of urban, African-American adolescents with asthma. Questionnaires were used to identify high school students with asthma, and to examine the association of body mass index (BMI) to asthma morbidity, by gender. Of 5967 students completing questionnaires, 599 (10%) met criteria for asthma and 507 had data sufficient for inclusion in further analyses (46% male, mean age = 15.1 yr). Univariately, BMI > 85th percentile was significantly related only to reported emergency department visits (ED) and school days missed for any reason, Odds Ratio (95%Confidence Interval) = 1.7(1.1-2.7), p = 0.01 and 1.8(1.1-3.0), p = 0.01, respectively. A significant gender-BMI interaction (p < 0.05) was observed in multivariate models for ED visits, hospitalizations and school days missed for asthma. In gender-specific models, adjusted Risk Ratios for BMI > 85th and ED visits, hospitalizations, and school days missed because of asthma were 1.7(0.9-3.2), 6.6(3.1-14.6) and 3.6(1.8-7.2) in males. These associations were not observed in females. Gender modifies the association between BMI and asthma-related morbidity among adolescents with asthma. Results have implications for clinical management as well as future research.

Prenatal exposure to household pets influences fetal immunoglobulin E production

BACKGROUND

Early life pet exposure may protect against allergic sensitization during childhood. Few studies have evaluated the effect of prenatal pet exposure on potential neonatal markers of allergic risk.

OBJECTIVE

The aim of this study was to investigate whether maternal exposure to pets affects cord blood IgE levels in a population-based, general risk, ethnically mixed birth cohort.

METHODS

Pet keeping during pregnancy was ascertained from women residing in a defined area of Wayne County Michigan and recruited from five staff model obstetric clinics. Maternal venous blood was analysed for total and allergen-specific IgE along with cord blood total IgE from 1049 infants.

RESULTS

Compared with infants from households with no cats or dogs kept indoors during pregnancy, infants whose homes had either cats or dogs had significantly reduced mean cord IgE levels [0.34 IU/mL (95% CI 0.30-0.38) vs. 0.24 IU/mL (0.20-0.27), P=0.025]. Similar effects were apparent in cat-only households [0.21 IU/mL (0.16-0.27), P=0.020] and dog-only households [0.24 IU/mL (0.19-0.29), P=0.045]. There was no effect on results when excluding mothers who reported avoiding pets due to allergy-related concerns.

CONCLUSION

Mothers with either cats or dogs in their home during pregnancy deliver children with lower cord blood IgE levels compared with mothers who do not live with these pets, supporting the hypothesis that pet exposure influences immune development in a manner that is protective for atopy and is operant even before birth.

A critical review of the use of Clara cell secretory protein (CC16) as a biomarker of acute or chronic pulmonary effects

Biomarkers associated with asthma aetiology and exacerbation have been sought to shed light on this multifactorial disease. One candidate is the serum concentration of the Clara cell secretory protein (CC16, sometimes referred to as CC10 or uteroglobin). In this review, we examine serum CC16's relation to asthma aetiology and exacerbation. There is evidence that acute exposures to certain pulmonary irritants can cause a transient increase in serum CC16 levels, and limited evidence also suggests that a transient increase in serum CC16 levels can be caused by a localized pulmonary inflammation. Research also indicates that a transient increase in serum CC16 is not associated with measurable pulmonary damage or impairment of pulmonary function. The biological interpretation of chronic changes in serum CC16 is less clear. Changes in serum CC16 concentrations (either transient or chronic) are not specific to any one agent, disease state, or aetiology. This lack of specificity limits the use of serum CC16 as a biomarker of specific exposures. To date, many of the critical issues that must be understood before serum CC16 levels can have an application as a biomarker of effect or exposure have not been adequately addressed.

Passive cigarette smoke exposure of infants: importance of nonparental sources

OBJECTIVE

To learn whether cigarette smoking by persons other than parents significantly contributes to the passive environmental tobacco smoke (ETS) exposure of infants.

STUDY DESIGN

A cohort of infants prospectively followed up from birth to age 2 years with monthly questionnaires concerning smoking by different categories of adults coming into contact with the infants.

SETTING

Health maintenance organization members residing in several suburban communities of Detroit, Mich, defined by contiguous ZIP codes.

SUBJECTS

Ninety-seven (83%) of 117 healthy, full-term infants, thought to be at high risk of allergic disease based on cord blood IgE, who were born to eligible mothers and who completed 24 months of follow-up.

MAIN OUTCOME MEASURES

Average of bimonthly urinary cotinine-creatinine ratios (CCRs) during the 2 years of the study.

RESULTS

There were significant correlations (r</=0.28, P</=.005) between the frequency of smoking by all 7 categories of adults considered and the average CCRs of the infants. Multivariable analysis demonstrated that average urinary CCRs were significantly associated not only with smoking by the infant's parents, but also with smoking by workers at day care away from the home, persons visited away from the home, and persons other than parents residing in the home (overall R(2) = 0.72, P =.001).

CONCLUSIONS

Smoking by multiple individuals, other than the parents, significantly contributes to the ETS exposure of infants. These findings suggest that, at least for infants, efforts to reduce the adverse health effects of ETS exposure should extend beyond curtailing parental smoking. Arch Pediatr Adolesc Med. 2000;154:1237-1241.

Quantitative IgE antibody assays in allergic diseases

During the past several years, immunoassays for specific IgE antibodies have been refined to permit reporting results in mass units. Thus quantitative immunoassays for IgE antibodies may be an adjunct to skin tests. In cases of food allergy among children with atopic dermatitis, cutoff values for IgE antibody concentrations to egg, milk, peanut, and fish have been derived to provide 95% positive and 90% negative predictive values. Food-specific IgE antibody determinations can also be used to predict which food allergies are resolving spontaneously. Elevated egg-specific IgE antibody levels in infancy are associated with significantly increased risk for development of inhalant allergies later in childhood. In cases of inhalant allergy, specific IgE antibody levels correlate closely with results of inhalation challenge studies in cat-sensitive persons. Also, mite-specific IgE antibody levels correlate significantly with the mite allergen contents of reservoir dust in the homes of mite-sensitive persons. Immunoassays for quantitation of specific IgE antibodies may be used to document allergen sensitization over time and to evaluate the risk of reaction on allergen exposure. However, immunoassays and skin tests are not entirely interchangeable, and neither will replace the other in appropriate circumstances.

Factors related to methacholine airway responsiveness in children

Studies of airway responsiveness (AR) have typically used similar dose schedules of methacholine for adults and children despite large ranges in subject size. Reported declines in AR with increasing age in children could be due to maturational changes or to proportionately smaller doses of methacholine in taller (older) children. Other investigators have related both height and various measures of lung function to AR. We examined data related to AR in 471 children, aged 6 to 8 yr, from a birth cohort. Each child underwent spirometry followed by sequential challenge with five doses of methacholine, ranging from 0.025 to 25 mg/ml, given with a dosimeter. Continuous slope and end FEV(1)-change indexes of responsiveness were computed. Using stepwise regression modeling, we found no significant association between AR and either height or age after entering a variable reflecting asthma or wheezing. In contrast, we found that baseline measures of FVC, FEV(1)/FVC, and FEF(25-75%) were significantly related to AR after controlling for other variables (p = 0.001). However, when all three of the latter measures were added to models, FEF(25-75%) was most closely related to AR. We conclude that after control for other variables, FEF(25-75%) and FVC, but not height, are significantly related to methacholine responsiveness in children.

Racial differences in physiologic parameters related to asthma among middle-class children

BACKGROUND

Asthma morbidity and mortality are higher in the United States for African-American (AA) children when compared to European-American (EA) children.

STUDY OBJECTIVES

To explore racial differences in physiologic factors associated with pediatric asthma severity.

DESIGN

Cross-sectional.

METHODS

We analyzed data from two groups of children in suburban Detroit, one of which contains non-urban, middle-class AA children, a group not usually included in childhood asthma studies. All children were 6 to 8 years of age. Clinical evaluations included medical history, physical examination, skin testing, spirometry, and methacholine challenge.

RESULTS

The study population (n = 569) was 14% African American, 51% of the participants were male, and the mean age was 6.8 +/- 0.4 years. Socioeconomic status (parental education) was similar overall by race, although some strata-specific differences were observed. The prevalence of physician-diagnosed asthma was 10% for both AA and EA groups. AA children were more reactive to methacholine than EA children (42% vs 22%, respectively; p = 0.001), and had significantly higher total IgE than EA children (geometric mean, 60. 6 vs 27.5 IU/mL; p = 0.001). Serum IgE was related to methacholine reactivity in EA children (p = 0.001), but not AA children (p = 0. 73). These differences remained after adjustment for gender, age, parental education, parental smoking, and maternal smoking during pregnancy.

CONCLUSIONS

Our data support previous reports of racial differences in lung volume, airway responsiveness, and serum IgE concentrations. We found a racial difference in the relationship between total serum IgE and airway responsiveness that is unreported elsewhere. Overall, our results suggest that AA children may be predisposed to asthma.

Predicting asthma severity from allergic sensitivity to cockroaches in pregnant inner city women

OBJECTIVE

To measure and compare cockroach (CR)-specific immunoglobin E (IgE) in sera from pregnant women with mild, moderate and severe asthma.

STUDY DESIGN

CR IgE levels were measured in stored sera collected during the Collaborative Perinatal Project. Three matched groups of 93 women were formed: group I (mild), history of asthma but no acute exacerbation; group II (moderate), acute asthma exacerbation; group III (severe), required hospitalization for a diagnosis of status asthmaticus. ANOVA was used to compare the three means.

RESULTS

Mean CR IgE paralleled prenatal asthma severity. Mean values were 6.50, 13.12 and 28.99 kU/L for groups I, II and III, respectively (P = .06). High allergen sensitivity, defined as CR IgE > 60 kU/L, was identified in 8 of the 93 study samples. The prevalence of high allergen sensitivity increased as clinical asthma became more severe. Sixty-two percent (5/8) of the high allergen sensitivity occurred in group III.

CONCLUSION

There appears to be a positive correlation between sensitivity to CR allergens and asthma severity during pregnancy, and these findings support further evaluation of CR allergen sensitivity as a predictor of asthma severity in pregnancy.

Identification of bovine IgG as a major cross-reactive vertebrate meat allergen

BACKGROUND

Although beef is a main source of protein in Western diets, very little has been published on allergic reactions to beef or the main allergens implicated in these reactions. The aim was to evaluate the IgE antibody response to beef in suspected meat-allergic subjects and assess cross-reactivity of beef with other vertebrate meats.

METHODS

Fifty-seven sera from suspected meat-allergic subjects were tested by grid blot for specific IgE antibodies to vertebrate meats (beef, lamb, pork, venison, and chicken), and the patterns of recognition of meat proteins were assessed by immunoblot studies.

RESULTS

A 160-kDa band, identified as bovine IgG, was detected in raw beef in 83% (10/12) of beef-allergic subjects but in only 24% of the beef-tolerant subjects. IgE reactivity to a band of similar mol. mass was detected also in lamb and venison, but rarely in pork or chicken. Complete inhibition of the IgE reactivity to the bovine IgG was obtained with lamb, venison, and milk. IgE reactivity to this band also completely disappeared when beef or lamb extracts were separated under reducing conditions, indicating conformational epitopes.

CONCLUSIONS

Bovine IgG appears to be a major cross-reacting meat allergen that could predict beef allergy. Further studies with oral IgG challenges should be performed to document the conclusion that in vitro reactivity correlates with clinical hypersensitivity. The role of bovine IgG in other bovine products such as milk, dander, or hair must also be studied, and the hypothesis that it is a cross-reacting allergen with other mammalian products validated.

A blinded, multi-center evaluation of two commercial in vitro tests for latex-specific IgE antibodies

PURPOSE

To compare the diagnostic value of two commercial in vitro tests for the detection of latex-specific IgE antibodies.

METHODS

Serum samples were collected from latex-allergic and nonlatex-allergic individuals. Persons were classified as latex allergic if they had a positive clinical history and a positive skin prick test with a latex extract. Persons with no latex-related symptoms and negative skin tests were classified as nonlatex allergic. The serum samples were tested in a blinded fashion by a laboratory using the CAP (Pharmacia-Upjohn) and AlaSTAT (Diagnostic Products Company) assays. Values of 0.35 kA U/L or greater were considered positive in both tests.

RESULTS

The 143 sera studied came from 83-latex allergic and 60 nonallergic persons. The in vitro tests were found to have sensitivities of 79.5% and 73.8%, and specificities of 90.2% and 91.7%, for CAP and AlaSTAT, respectively. The positive predictive values were 91.7% and 92.5%, while the negative predictive values were 76.4% and 71.4% for the CAP and AlaSTAT, respectively.

CONCLUSION

In individuals classified by the combination of clinical history and skin test results, both the Pharmacia CAP and the DPC AlaSTAT demonstrated acceptable sensitivities, specificities, and predictive values for detection of antilatex IgE antibodies. These findings suggest that both assays can be useful adjuncts to the diagnosis of latex allergy.

Evaluation of air and dust sampling schemes for Fel d 1, Der f 1, and Der p 1 allergens in homes in the Detroit area

BACKGROUND

Studies often use a point estimate of allergen exposure without fully justifying the accuracy of this single measure as an estimate of total exposure. Many studies have reported relationships between indoor allergen concentrations and manifestations of allergic disease on the basis of single samples.

OBJECTIVES

The purposes of this study were to (1) characterize the variability in dust and air concentrations of allergens, (2) assess the relationships between dust and air concentrations of allergens, and (3) determine the minimum number and timing of samples to characterize annual indoor allergen exposure.

METHODS

As part of a prospective cohort study of asthma in children, air and dust samples were repeatedly obtained from the homes of children residing in suburban Detroit, Michigan. Concentrations of Fel d 1, Der f 1, and Der p 1 were measured in the samples. The results of various patterns of sampling were compared with yearly averages.

RESULTS

The concentrations of all 3 allergens in both air and dust varied widely both within and between homes. The allergen concentrations had peak concentrations in the fall. There was little correlation between air and dust concentrations. Our results indicate that as few as 2 or 3 samples taken late in the year provide good estimates of the annual average concentrations.

CONCLUSIONS

Two or 3 samples, obtained 1 month apart and taken late in the year, represent the best balance between sampling effort and accuracy of the yearly exposure estimates of Fel d 1, Der f 1, and Der p 1 in temperate climates similar to those of Detroit, Michigan.

Gender differences in total and allergen-specific immunoglobulin E (IgE) concentrations in a population-based cohort from birth to age four years

While serum immunoglobulin E (IgE) concentration has been shown to be related to allergic disease, there have been few studies of the natural history of IgE development in young children. This study compared total and allergen-specific serum IgE concentrations, by gender, from birth through 4 years of age using a population-based cohort of normal children followed from 1987 to 1993. Subjects were enrolled from a geographically defined area through membership in a large health maintenance organization, and they resided in the northern suburbs of Detroit, Michigan. Total IgE concentrations were measured at birth and at 2 and 4 years of age. Specific IgE concentrations to selected common inhalant allergens (dust mite (Dematophagoides farinae), cat, ragweed (Ambrosia artemisiifolia), and timothy grass (Pheleum pratense)) were measured at 2 and 4 years of age. Total IgE increased with age from birth to 4 years for boys and girls, and was higher in boys at 2 and 4 years of age. Girls demonstrated significant increases in IgE to mite and cat and decreases in IgE to ragweed and timothy from 2 to 4 years of age, whereas there was little change for boys except an increase in IgE to ragweed. Differences in IgE development between young boys and girls may partially account for the higher prevalence of asthma in boys than in girls.

Racial differences in emergency department use persist despite allergist visits and prescriptions filled for antiinflammatory medications

BACKGROUND

African-American children use the emergency department (ED) for asthma care more than their Caucasian counterparts.

OBJECTIVE

We sought to compare ED utilization for asthma care by race, adjusting for prescriptions filled for antiinflammatory medications, type of index visit (specialist vs nonspecialist), and demographic variables.

METHODS

An index asthma visit was identified for a cohort of managed care enrollees aged 4 to 11 years. Information on asthma encounters and drug claims data was evaluated during a prospective observation period of 12 months.

RESULTS

African-American race was associated with one or more ED visits during the observation period (relative risk [RR] = 1.8, 95% CI = 1.3 to 2.5, p < 0.01). After adjusting for index visit type, prescriptions filled, and selected demographic variables, African-American race remained associated with post-index ED utilization (adjusted RR = 1.6, 95% CI = 1.0 to 2.4, p = 0.05). Additional findings included an inverse relationship between African-American race and antiinflammatory medications among children with nonspecialist index visits (RR = 0.5, 95% CI = 0.3 to 0.9, p = 0.02) and a positive relationship between African-American race and hospitalization after an ED visit for asthma care (RR = 10.2, 95% CI = 1.4 to 74.8, p < 0.01).

CONCLUSION

African-American children were more likely to use ED asthma care even after adjusting for the type of index visit, prescriptions filled for antiinflammatory medications, and selected demographic variables. Racial differences in ED utilization for asthma care could be caused by a higher prevalence of uncontrolled or undertreated disease among African-American children not receiving specialty care.

Use of urinary cotinine and questionnaires in the evaluation of infant exposure to tobacco smoke in epidemiologic studies

Exposure to environmental tobacco smoke is an important variable in many pediatric epidemiologic studies. We measured urinary cotinine, a specific metabolite of nicotine, in a population-based cohort of children every other month from birth through two years of age. Extensive data regarding exposure to smokers (people in the home, in home and away from home day care, home visitors, visits to smokers) were collected monthly by way of home interviews. We evaluated, with multiple cotinine measurements as the gold standard, other measures of exposure that are more feasible to obtain in large-scale studies. Comparing one cotinine to the average of multiple measurements, we found that 33.7% were in error in excess of 100 ng/mg, but 84% of the infants could be correctly classified into categories of low versus high. Parental smoking patterns had the highest predictive accuracy (fathers 67.0% and mothers 64.1%). Combining selected smoker categories (either parent, other home residents outside day care workers) resulted in improved accuracy of 79.3%.

The incidence of latex sensitivity in ambulatory surgical patients: a correlation of historical factors with positive serum immunoglobin E levels

Increasing reports of latex-induced anaphylaxis make preoperative identification of latex-sensitive individuals an important concern. The incidence of latex sensitivity and the efficacy of questionnaires in identifying this in ambulatory surgical populations have not been determined. To clarify these issues, 996 ambulatory surgical patients were studied preoperatively. A questionnaire addressing demographic information, previous surgeries, history of atopy, previous exposure or reactions to latex, congenital abnormalities, and food allergies was administered. These data were then compared with serum anti-latex immunoglobin E (IgE) levels (AlaSTAT test), and risk factors, sensitivity, and specificity were determined. Of this population, 6.7% had IgE antibodies against latex (i.e., latex sensitivity). Male gender, non-Caucasian race, age, asthma, spinal cord abnormalities, food allergies, stated latex allergy, and symptoms when exposed to latex increased the risk of latex sensitivity. The specificity and positive predictive value of history were low. No systemic allergic reactions occurred, a finding that could be attributed to chance alone. The incidence of latex sensitivity in this population suggests that latex allergy is a significant potential problem in ambulatory surgical patients. History, however, does not appear to be a reliable predictor of the presence of anti-latex antibodies.

Ethnic differences in the prevalence of asthma in middle class children

BACKGROUND

Studies have shown a higher prevalence of asthma among boys compared with girls and in blacks compared with whites, but it has been difficult to separate socioeconomic from racial effects because the blacks in the studied populations were more likely to have low socioeconomic status.

OBJECTIVE

To compare the prevalence of asthma in a socioeconomically homogeneous, middle class, multiethnic population of schoolchildren.

METHODS

Based on a telephone survey of all families of third-graders in Southfield, Michigan, we ascertained the prevalence of physician-diagnosed asthma and probable undiagnosed asthma. One reason Southfield was chosen for study was because the city comprises an integrated middle class population with only 4% blacks and 7% whites having incomes below federal poverty limits.

RESULTS

The lifetime prevalence of asthma was 9.5% (12% for blacks and 6% for whites) and higher in boys (14%) than girls (5%), a pattern that was reflected in period prevalence estimates. The lifetime prevalence of probable undiagnosed asthma was greater in blacks (16.6%) than whites (10.8%), with little sex difference. Adjusting for sex and maternal education, the prevalence of physician-diagnosed asthma and probable asthma were associated independently with black ethnicity.

CONCLUSIONS

Our study is unique in the similarity of the black and white families' socioeconomic status and residence in the same middle class community. Since access to medical care and macro-environmental conditions were similar across this study population, our results are consistent with the hypothesis that differences in biologic factors between blacks and whites and boys and girls play a role in asthma risk.

Incidence and prevalence of physician-diagnosed asthma in a suburban population of young adults

BACKGROUND

Asthma is a common chronic disease of both children and adults, but there have been few reports of the incidence of asthma in well defined adult populations.

OBJECTIVE

To determine the incidence and prevalence of asthma in a population of young adults living in suburban Detroit.

METHODS

As part of a study of the development of allergic disease in children, the parents of 841 study children, from a defined, well characterized population, were questioned about their personal histories of allergic disease, including asthma, during the mother's pregnancy. The children have been followed from birth until 4 years of age. When the child became 4, the parents were again questioned about allergic disease. Those reporting asthma when the child was 4 but not prior to the child's birth, were recontacted to confirm that they had been diagnosed by a physician as having asthma in the 4-year interval. Because of prior reports concerning racial differences in the prevalence of asthma and the small number of non-white mothers in the study population, calculations of asthma prevalence and incidence were limited to the 760 mothers, who described themselves and their baby's father as white.

RESULTS

The parents studied were young adults mean age 28.7 [(standard deviation (SD) 4.5 years] and 31.0 (SD 5.0) years, of mothers and fathers, respectively. These parents were relatively well educated with 30.7% of mothers and 43.5% of fathers having college degrees. The initial prevalence of a previous physician diagnosis of asthma was 7.5% [95% confidence interval (95% CI) = 5.7-9.6] in the mothers and 6.9% (95% CI = 5.2-9.0) in the fathers, yielding a total prevalence of 7.2% (95% CI = 5.9-8.7) in these 1484 adults. Five hundred thirty-three mothers and 498 fathers (total = 1031), who did not report asthma during the mothers' pregnancies, were available for questioning when the children were 4 years old. The average yearly incidence of asthma was 5.2 (95% CI = 2.6-9.2) per 1000 in the mothers and 1.5 (95% CI = 0.3-4.4) per 1000 in the fathers (P = .058), with an overall incidence of 3.4 (95% CI = 1.8-5.7) per 1000. The average yearly incidence was 5.3/1000 in those < 30 years old and 1.5/1000 in those > or = 30 years of age (P = .056).

CONCLUSIONS

We conclude that the incidence of asthma in this population of relatively young, well educated, white adults is approximately 3.4 per 1000 per year and that newly diagnosed asthma was more common in women and in those < 30 years of age.

The prevalence of anti-latex IgE antibodies among registered nurses

BACKGROUND

Recent studies have reported that the prevalence of latex allergy among volunteer populations of health care workers ranges from 2% to 25%. To date, no epidemiologic study has investigated the prevalence of latex allergy and its relationship to possible risk factors among nurses.

METHODS

Registered nurses (n = 741) in a large metropolitan hospital participated in a latex allergy prevalence study. Latex exposure data were obtained through self-administered questionnaires. Blood samples were classified as positive or negative for anti-latex IgE antibodies. Associations between potential risk factors for latex allergy and anti-latex antibodies were assessed.

RESULTS

The participation rate was 90.6% among eligible nurses. Sixty-five samples were positive for a prevalence of 8.9% (95% confidence interval, 6.7 to 10.8). No differences in latex positivity among five nursing specialties were noted. Logistic regression indicated that after adjusting for age and sex, the following factors were significantly associated with latex seropositivity: nonwhite race (odds ratio [OR] = 4.2), reported histories of penicillin allergy (OR = 2.2), pruritic skin (OR = 2.2), conjunctivitis (OR = 3.0), localized urticaria (OR = 1.8), hay fever (OR = 2.1), avocado allergy (OR = 9.9), and ragweed allergy (OR = 3.4).

CONCLUSIONS

The prevalence of latex sensitization appeared to be substantial (8.9%) among the nurses studied, and the prevalence did not vary by nursing specialty. The factors associated with latex positivity in the logistic regression model correctly classified 81.3% of the nurses with a sensitivity and specificity of 66.7% and 82.7%, respectively.

Evaluation of IgA measurements as a method for detecting maternal blood contamination of cord blood samples

Several studies have evaluated the value of cord blood IgE concentrations for predicting the risk of allergic disease in children. In all of these studies it is necessary to exclude cord blood samples in which the IgE may be falsely elevated due to admixing of maternal and fetal blood during parturition. The most common method for detecting mixing of fetal and maternal blood is measurement of cord blood IgA concentrations. We have examined the theoretical basis of IgA measurements for detecting maternal blood contamination and reexamined our own data to evaluate IgA measurements. Our data suggest that the average IgA concentration of 28.2 micrograms/ml used in previous studies may not adequately exclude contaminated cord blood sample. Failure to reject contaminated cord blood samples would reduce the positive predictive value of cord blood IgE measurements.

Parental history of atopic disease and concentration of cord blood IgE

BACKGROUND

A family history of atopy, and cord blood immunoglobulin E concentration, have been shown to be predictors of atopic disease in children. Several studies have suggested that parental atopy may be related to newborn immunoglobulin E.

OBJECTIVE

The purpose of our analysis was to evaluate whether parental history of allergic disease was associated with cord blood immunoglobulin E concentration.

METHODS

The study subjects were from a defined population of 777 newborns delivered between 1987 and 1989. The mothers of these children completed a questionnaire during pregnancy concerning themselves and the child's father, including parental history of physician diagnosis of allergic diseases (allergies, hay fever and asthma). Total immunoglobulin E levels were quantitated in cord blood samples with an enzyme-linked immunoassay.

RESULTS

Median cord blood immunoglobulin E concentration was higher among infants whose mothers had a history of atopic disease, particularly for those with a history of asthma (P < 0.022) and allergen immunotherapy (P < 0.016) vs infants whose mothers had no history of any atopic disease. Comparing all babies with a maternal history of asthma, to babies where neither parent had a history of any atopic disease, the median cord blood immunoglobulin E was significantly higher (0.36 IU/mL vs 0.21 IU/mL; P < 0.009). This association was found only among female infants (0.49 IU/mL vs 0.20 IU/mL; P < 0.001).

CONCLUSION

Maternal, but not paternal, history of atopic disease was associated with an elevated immunoglobulin E among newborns. For maternal asthma, this association was only evident in infant girls.

The prevalence of anti-latex IgE antibodies in 1000 volunteer blood donors

BACKGROUND

Latex allergy has been recognized as a medical problem with increasing frequency since the mid 1980s. Although certain groups of individuals, such as health care workers, have been recognized as having increased risk for latex allergy, little is known about the prevalence of latex allergy in the general population.

METHODS

To estimate the prevalence of latex allergy among healthy adults, we measured anti-latex IgE antibodies in residual serum samples from 1000 volunteer Red Cross blood donors. The 1000 samples were from a sample of blood units collected from workplace mobile sites throughout Southeastern Michigan. Samples collected from mobile sites operating at health care institutions were excluded to minimize sampling of health care workers. Anti-latex IgE antibodies were measured by using the AlaSTAT assay (Diagnostic Products Corp., Los Angeles, Calif.) according to the manufacturer's directions. Samples with anti-latex IgE concentrations of 0.35 IU/ml or greater were classified as positive and samples with IgE concentrations of 1.50 IU/ml or greater were classified as strongly positive. All positive samples were assayed a second time to confirm the result. All positive samples were also measured with the CAP assay (Pharmacia Diagnostics, Dublin, Ohio).

RESULTS

The samples tested were from donors with a mean age of 37.8 years, and 47% were women. Sixty-four (6.4%, 95% confidence interval = 4.9-8.1%) of the samples were confirmed as repeatedly positive for anti-latex IgE, and 23 of the 64 positive samples were strongly positive (2.3% of the 1000). Sixty-one percent of the samples positive as determined by the AlaSTAT assay were also positive as determined by the CAP assay. Samples from male donors were more likely to be positive than those from female donors (8.7% vs 4.1%, p = 0.003). Prevalence of positive samples was not related to age or race.

CONCLUSIONS

We conclude that the prevalence of detectable anti-latex IgE antibodies, in a large and relatively unselected adult population, is higher than previous estimates have suggested. Although the clinical significance of these observations needs further evaluation, the data suggest that latex allergy is not confined to individuals in previously recognized high-risk groups.

Cat shedding of Fel d I is not reduced by washings, Allerpet-C spray, or acepromazine

BACKGROUND

No published studies have compared the effectiveness of several treatments proposed to reduce cat allergenicity. Cat washing studies demonstrating efficacy involved very small sample sizes or infrequent washings. Allerpet-C (Allerpet, Inc., New York, N.Y.), a widely advertised topical spray, and acepromazine, a tranquilizer advocated as efficacious in subsedating doses, have never been scientifically studied.

OBJECTIVE

We compared the effects of cat washing, Allerpet-C spray, and acepromazine with that of no treatment on the shedding of the primary cat allergen, Felis domesticus I by cats.

METHODS

In a blinded, comparative, controlled study, we measured the amounts of Fel d I shed during an 8-week treatment period with a sample of 24 female mongrel cats randomly assigned to four groups; one group received weekly distilled water washings, one received weekly Allerpet-C spray applications, one received daily oral acepromazine, and one had no treatment (control). Thirty-minute, twice-weekly air samples were collected from each cat with a laminated plastic-acrylic chamber and air sampler.

RESULTS

One-sample, two-sided t tests comparing baseline to final-week measurements revealed no significant change in Fel d I within each group (mean change +/- SD: washing; 487.6 +/- 1896.4 mU per 30 minutes, p = 0.63; Allerpet-C spray, 429.2 +/- 871.6 mU per 30 minutes, p = 0.46 acepromazine; -620.6 +/- 1031.2, p = 0.52 per 30 minutes). Furthermore, analysis of covariance revealed no significant change in Fel d I levels between groups (p = 0.72).

CONCLUSIONS

Out data do not show significant reductions in Fel d I shedding as a result of any of these treatments. Therefore we cannot recommend them to patients allergic to cats.

Prevalence of latex-specific IgE antibodies in patients being evaluated for allergy

OBJECTIVE

The purpose of this study was to determine the prevalence of detectable latex-specific IgE in patients being evaluated for allergy.

METHODS

The AlaSTAT assay was used to test for latex-specific IgE in 200 consecutive serum samples sent to our laboratory for total IgE levels. Samples sent for latex-specific IgE were excluded. The population studied included 87 males and 113 females ranging in age from 1 to 82 years of age. Inhibition studies with a latex extract were performed on all positive samples. Chart reviews and questionnaires provided information regarding risk factors for latex allergy and reactions to latex.

RESULTS

Twenty-four (12%) subjects were positive for latex-specific IgE. Seventeen of the 24 positive subjects (70.8%) were < 18 years of age and all of the strongly positive subjects (7 or 3.5%) were < 18 years of age. The geometric means for total IgE for the latex positive and negative subjects were 351 IU/mL and 80 IU/mL respectively, P < .001. The mean percent inhibition with latex was 66%. Chart reviews and questionnaires revealed only 2 of 24 positive subjects were in high risk groups, none of the positive subjects had any history of reactions to latex, and 22 (91.6%) had evidence of atopic disease.

CONCLUSION

In vitro tests may detect latex specific IgE in atopic individuals, especially children, with no history of recurrent latex exposure and no history of adverse reactions to latex.

The appropriate use of skin testing and allergen immunotherapy in young children

Immunotherapy is clearly effective in the treatment of allergic rhinitis and Hymenoptera sensitivity and probably effective in the treatment of asthma. Few studies evaluate the risks and benefits of immunotherapy in young children. Current evidence suggests that young children are at increased risk for systemic reactions from immunotherapy. Furthermore, immunotherapy or adverse reactions resulting from immunotherapy may result in significant psychologic problems. The potential risks of immunotherapy would be justified if immunotherapy were demonstrated to be safe and additive to other therapies. Immunotherapy might be particularly effective in treating or helping to prevent house dust mite- or cockroach-associated asthma. Until the efficacy of immunotherapy is demonstrated in young children, we agree with the European Academy of Allergology and Clinical Immunology position that immunotherapy in young children is relatively contraindicated.

Multi-centre comparison of ABBOTT MATRIX Aero to Pharmacia Standard RAST, Modified RAST and skin puncture tests

ABBOTT MATRIX Aero is an enzyme immunoassay which measures specific IgE antibodies to 14 individually calibrated airborne allergens using a single serum specimen. In this study, ABBOTT MATRIX performance was evaluated in comparison to the results of skin puncture test and the Standard and Modified RAST procedures. The ABBOTT MATRIX demonstrated overall sensitivity of 89% vs. Standard RAST and Modified RAST, with specificity greater than 92% vs. both methods. ABBOTT MATRIX sensitivity vs. skin test (71%) exceeded that of the Standard and Modified RAST procedures (62% and 67% respectively). Positive results reported by ABBOTT MATRIX but not RAST were corroborated by skin test results for 3 of 5 allergens evaluated. All in vitro systems demonstrated specificity of approximately 90% vs. skin test. The ABBOTT MATRIX system provided results which compared favorably with the results of skin test and RAST, but required less hands-on time to obtain quantitative specific IgE measurements to multiple allergens.

Somatic mosaicism for a newly identified splice-site mutation in a patient with adenosine deaminase-deficient immunodeficiency and spontaneous clinical recovery

Absent or severely reduced adenosine deaminase (ADA) activity produces inherited immunodeficiency of varying severity, with defects of both cellular and humoral immunity. We report somatic mosaicism as the basis for a delayed presentation and unusual course of a currently healthy young adult receiving no therapy. He was diagnosed at age 2 1/2 years because of life-threatening pneumonia, recurrent infections, failure of normal growth, and lymphopenia, but he retained significant cellular immune function. A fibroblast cell line and a B cell line, established at diagnosis, lacked ADA activity and were heteroallelic for splice-donor-site mutation in IVS 1 (+1GT-->CT) and a missense mutation (Arg101Gln). All clones (17/17) isolated from the B cell mRNA carried the missense mutation, indicating that the allele with the splice-site mutation produced unstable mRNA. In striking contrast, a B cell line established at age 16 years expressed 50% of normal ADA; 50% of ADA mRNA had normal sequence, and 50% had the missense mutation. Genomic DNA contained the missense mutation but not the splice-site mutation. All three cell lines were identical for multiple polymorphic markers and the presence of a Y chromosome. In vivo somatic mosaicism was demonstrated in genomic DNA from peripheral blood cells obtained at 16 years of age, in that less than half the DNA carried the splice-site mutation (P < .002, vs. original B cell line). Consistent with mosaicism, erythrocyte content of the toxic metabolite deoxyATP was only minimally elevated. Somatic mosaicism could have arisen either by somatic mutation or by reversion at the site of mutation. Selection in vivo for ADA normal hematopoietic cells may have played a role in the return to normal health, in the absence of therapy.

Anaphylaxis after ingestion of beignets contaminated with Dermatophagoides farinae

A 48-year-old man was evaluated for anaphylaxis associated with ingestion of beignets prepared from a commercial mix. Microscopic examination of the patient's beignet mix revealed live Dermatophagoides farinae. Another unopened box from the same source was not infested. Skin test results to aeroallergens and foods, including all beignet mix ingredients, were positive only to D. farinae and D. pteronyssinus extracts. Skin prick test results to an infested mix extract (1:5 wt/vol) were also positive, but no reaction was observed with noninfested mix extract. ELISA inhibition studies demonstrated significant inhibition of the patient's serum binding to D. farinae strips by infected mix extract. Parallel inhibition curves were produced by the infested mix extract and a commercial D. farinae extract. Noninfested mix extract showed no inhibition. RAST analysis with beignet mix discs showed significant binding of the patient's serum IgE to infested mix discs but not to noninfested mix discs. RAST inhibition studies revealed more than 86% inhibition of binding of the patient's IgE to infested mix discs by infested mix extract and D. farinae extract. No inhibition was observed with noninfested mix or 5% fetal calf serum-phosphate-buffered saline. We conclude that the allergen to which the patient reacted was most likely D. farinae and that ingestion of D. farinae may cause anaphylaxis in sensitive persons.

Ubiquitous presence of cat allergen in cat-free buildings: probable dispersal from human clothing

Fel d I has been found in almost all houses investigated, including those in which cats have never been present. These observations have not been explained. We measured Fel dI in samples of carpet dust from ten newly built model homes, 14 occupied homes, six allergists' offices, five hospital corridors, and three shopping mall stores. We also measured Fel d I on T-shirts of persons with and without cats. Measurable amounts of Fel d I were found in all the dust samples. Fel d I found in older model homes exceeded that found in newer model homes (P < .05). The amounts of Fel d I found in allergists' offices, hospital corridors, and retail stores were similar to the amounts found in occupied homes without cats. Fel d I was found in all T-shirts sampled and increased with increasing exposure to cats. Our findings confirm and extend previous reports of the ubiquitous presence of cat allergen and are consistent with the hypothesis that Fel d I is carried into cat-free buildings on the clothing of people exposed to cats.

Relationship between dust mite allergen and human IgA in house dust samples

Previous investigators have mentioned that human IgA is found in house dust. IgA has also been reported to be present on human skin and hence in human dander. If human dander is the primary source of food for house dust mites, a relationship would be expected between IgA and dust mite allergen (Der f I) concentrations. We wished to learn whether IgA was consistently detectable in house dust and whether IgA and dust mite allergen concentrations were related. Dust samples were collected from the bedrooms of infants enrolled in a prospective study designed to evaluate the relationship between early allergen exposure and childhood allergic disease. One hundred eighty samples were studied: 50 samples were the initial samples collected from the first 50 infants enrolled, 120 samples were monthly samples obtained from 10 other homes, and 10 additional samples were randomly selected for extraction in a nonprotein containing buffer to determine the percentage of total extractable dust protein contributed by IgA. Finally, nine commercial house dust extracts were studied to learn whether they were similar to the dust samples from study houses. Enzyme linked immunosorbent assays (ELISAs) were used to measure human IgA, human secretory IgA (sIgA) and Der f I concentrations in all of the dust extracts. We found that IgA was consistently present in house dust samples ranging from 3.2 to 2,396 micrograms of IgA per gram of dust. A strong correlation (r = .90) was found between IgA and sIgA concentrations. IgA constituted 0.27% to 6.04% of the total protein in dust samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence of cross-reactivity between olive, ash, privet, and Russian olive tree pollen allergens

In a clinical investigation, 103 Michigan residents with symptoms suggestive of allergic rhinitis or asthma were skin tested with olive (Olea europaea) pollen extract. Nineteen had positive reactions. Since the olive tree is not native to nor grown in Michigan, this study was undertaken to determine whether the skin test reactivity was the result of cross-reactivity among tree pollen allergens. ELISAs were developed to measure olive, ash (Fraxinus americana), privet (Ligustrum vulgare), and Russian olive (Elaeagnus angustifolia) specific IgE antibodies. Inhibition studies were performed to determine whether pollen extracts from each of these tree species could inhibit IgE antibody binding to olive extracts. Eleven of the 19 skin test-positive patients were olive-ELISA positive, eight either were ELISA-positive to ash, seven to privet and ten to Russian olive. There were significant correlations between the ELISA results to olive and each of the other three pollens. The inhibition studies demonstrated that all three of the tree pollens were capable of inhibiting the binding of IgE to olive extract in a dose-response fashion. IgE-immunoblot studies demonstrated several proteins common to olive, ash, and privet. Twelve of the olive skin test-positive patients were contacted and 75% were exposed to one or more of the studied trees in their yards. Five patients had traveled to areas where olive trees are grown. We conclude that there is a high degree of cross-reactivity among allergens from native Michigan trees and from olive trees. This cross-reactivity is the most likely reason for skin test reactivity to olive pollen extract in Michigan.

Occupational asthma in a beet sugar processing plant

A patient with occupational asthma in the beet sugar processing industry is described. Symptomatology, skin testing, immunologic testing, and specific bronchoprovocation testing indicate exposure to moldy sugar beet pulp was the cause of the patient's occupational asthma. Cooperation between the treating physician and public health authorities is encouraged.

Maternal smoking does not influence cord serum IgE or IgD concentrations

Increased cord blood IgE concentrations have been related to atopic risk in children, and a previous study reported increased cord blood IgE concentrations in smoking mothers. These associations suggest a relationship between maternal smoking during pregnancy and atopic risk. To evaluate this question, we prospectively studied parental smoking and cord blood IgE and IgD concentrations in a geographically defined group of women belonging to a health maintenance organization. Cord blood samples were obtained from 847 infants born to these women. Cotinine concentrations were measured in 114 cord blood samples to evaluate the veracity of the maternal smoking histories. Smoking during the prenatal period was reported by 144 mothers (17%) and 204 fathers (25%). Decreased birth weight and length were associated with maternal smoking (p less than 0.001 for both), confirming previous studies. Neither maternal nor paternal smoking was found to be associated with IgE level in univariate or multivariate analyses. Maternal and paternal smoking was associated with IgD (p = 0.03 and p = 0.06, respectively) in univariate analysis. In multiple regression analysis controlling for potentially confounding variables, the association between paternal, but not maternal, smoking and IgD was sustained (p = 0.05 and p greater than 0.20, respectively). Our data do not demonstrate that maternal or paternal smoking increases cord blood IgE.

Peak nasal inspiratory flow and Wright peak flow: a comparison of their reproducibility

The measurement of peak nasal inspiratory flow (PNIF) is a rapid, convenient, and objective way to assess nasal patency. It is used much less commonly, however, than Wright Peak Flow (WPF), in part, because of concerns about its reproducibility. In order to compare the reproducibility of PNIF with WPF, we obtained multiple measurements of both flows in each of ten healthy, nonsmoking, trained subjects five times throughout the same day and daily throughout the same week. Mean PNIFs (L/min) were 140 immediately after arising, 170 at breakfast time, 183 at lunch time, 170 at dinner time, and 161 at bedtime. Corresponding mean WPFs were 528, 528, 535, 535 and 531 L/min. Peak nasal inspiratory flow coefficients of variation representing minute to minute, hour to hour, and day to day variation were 9.8, 13.5, and 9.7, respectively. Corresponding coefficients of variation with WPF, 2.4, 1.9, and 2.3, were significantly lower. Variability of PNIF and WPF did not increase with increased time spans, suggesting that variation in airway size is less important than variation in technique. Responses to intranasal oxymetazoline, as determined by changes in PNIF and changes in subjective assessments of nasal patency, were then evaluated in ten patients with nasal obstruction. These persons noted a mean subjective improvement of 68% (P = .0002) and demonstrated a mean objective improvement of 21% (P = .05). Posttreatment PNIFs of many individuals who reported substantial subjective improvement failed to exceed the expected variability of the test. This experience fails to demonstrate the utility of PNIF determinations for routine clinical use.

Anaphylaxis associated with latex allergy during barium enema examinations

During the interval from January 1989 to March 1990, signs and symptoms of anaphylaxis developed in six patients during barium enema examinations in our institution. In all six cases the symptoms of anaphylaxis began during the procedure, usually within 10 min of starting the examination. The principal manifestation of anaphylaxis was severe hypotension, usually accompanied by edema and urticaria. The symptoms were considered potentially life threatening in all patients, and one patient died despite prompt recognition of the anaphylactic nature of the reaction and resuscitative efforts. Serum samples were obtained within a few hours of the reaction in two patients and at autopsy in the fatal case: all three samples showed elevated concentrations of mast cell tryptase, demonstrating the systemic release of anaphylactic mediators. In vitro tests demonstrated the presence of immunoglobulin E antibodies specific for latex allergens in five of the six cases. Further in vitro inhibition tests confirmed the specificity of the antibodies for latex allergens and demonstrated that similar allergens were found in both raw latex, latex gloves, and catheter balloons. Only one patient was willing to undergo a skin test, and her skin test was positive for extracts of latex products. After considering multiple possibilities, we conclude that the reactions associated with barium enemas observed in these six patients are most probably the result of latex allergy.