The lessons of noninterventional and interventional prospective studies on the development of atopic disease during childhood

Epidemiological survey of self-reported food allergy among university students in China

The aim of this study was to investigate the prevalence of self-reported food allergy among university students in China. A cluster-random sampling population-based cross-sectional study using self - administrated questionnaire was conducted with 2538 college students recruited from 6 universities in China. The questionnaire included data on age, sex, weight, height, FA, comorbid allergic diseases, family history, and understanding food allergy. Data were analyzed by SPSS 25.0 statistical software. Multivariate logistic regression analysis was performed to analyze the risk factors related to self-reported food allergy and estimate the odds ratio. A total of 2538 questionnaires were distributed to the undergraduate students and 2313 completely effective questionnaires were collected, the effective response rate was 91.1%. 834 males and 1479 females were recruited, and their age ranged from 18 to 25 years old. The prevalence of self-reported food allergy was 15.7%, and the rate of doctor-diagnosed food allergy was 8.4%. The leading food allergens included shrimp, shellfish, milk, egg, peach, mango, beef, and peanut, and the prevalence of shrimp allergy was the highest (5.8%). The main clinical manifestation included skin mucous membrane and respiratory symptoms. The prevalence of food allergy were statistically significant difference (P < .05) between different age groups, family history, sun exposure times, smoking, and antibiotic use. Over 45% college students know little about food allergy. The prevalence of self-reported food allergy among Chinese college students was high (15.7%). Shrimp was the main allergenic food, followed by shellfish, milk, egg, peach, and mango. Family history, sun exposure, obesity, and using antibiotics may be the influencing factors of food allergy. The Chinese undergraduates lacked the knowledge about food allergy. Thus, it is necessary to strengthen the health education program on food allergy for college students in China and other middle high-income nations.

Pediatric Spectrum of Allergic Diseases and Asthma in a Tertiary Level Hospital in Botswana: an Exploratory Retrospective Cross-Sectional Study

Purpose

This study aims to describe the spectrum of allergic diseases of children and adolescents in a single allergy treatment centre in Botswana, over a period of 8 years.

Patients and Methods

A retrospective cross-sectional study was conducted using medical records of all patients aged 18 years or younger, seen at an allergy treatment centre in Botswana. Data were presented descriptively. Association between variables was explored by χ²-test.

Results

Four hundred and seven patients with a mean age of 5.8 years (SD 4.4) at the time of presentation included 239 (58.7%) females and 365 (87.5%) black Africans. The most common diseases were asthma (n=249, 61.2%) followed by allergic rhinitis (AR) (n=232, 57.0%) and atopic dermatitis (AD) (n=165, 40.5%). One hundred and fifteen cases (46.2%) of asthmatic patients were skin prick test positive; sensitized to grass, moulds, dust mites and animal dander, in decreasing frequency, whereas those with allergic rhinitis (AR) and allergic conjunctivitis (AC) were sensitized to trees and all allergens identified in asthmatics. Concomitant asthma was diagnosed in 171 (73.7%) with AR, 71 (68.3%) with AC, 75 (45.5%) with AD and 42 (47.7%) with food allergy. The most common triggers for asthma exacerbations include upper respiratory tract infections, weather changes, and exposure to passive cigarette smoke. Paternal allergy and allergic disease in grandparents are predisposing factors for asthma (p=0.016 and p=0.001, respectively). Paternal allergy is also predisposed to AR (p=0.007), while maternal history of allergic disease was associated with AD (p=0.019).

Conclusion

The most common chronic pediatric conditions seen in our allergic disease study were asthma, allergic rhinitis and atopic dermatitis with the most common triggers being viral upper respiratory tract infections, weather changes and exposure to cigarette smoke, all of which are modifiable risk factors. This exploratory study lays the foundation for future interventional studies that may be directed towards the spectrum of allergic diseases.

Galacto-Oligosaccharide/Polidextrose Enriched Formula Protects against Respiratory Infections in Infants at High Risk of Atopy: A Randomized Clinical Trial

Background: Early nutrition affects the risk of atopy and infections through modifications of intestinal microbiota. The Prebiotics in the Prevention of Atopy (PIPA) study was a 24-month randomised, double-blind, placebo-controlled trial. It aimed to evaluate the effects of a galacto-oligosaccharide/polydextrose (GOS/PDX)-formula (PF) on atopic dermatitis (AD) and common infections in infants who were born to atopic parents and to investigate the relationship among early nutrition, gut microbiota and clinical outcomes. Methods: A total of 201 and 199 infants were randomized to receive a PF and standard formula (SF), respectively; 140 infants remained on exclusive breastfeeding (BF). Results: The cumulative incidence of AD and its intensity and duration were not statistically different among the three groups. The number of infants with at least one episode of respiratory infection (RI) and the mean number of episodes until 48 weeks of age were significantly lower in the PF group than in the SF group. The number of patients with recurrent RIs and incidence of wheezing lower RIs until 96 weeks were lower in the PF group than the SF group, but similar to the BF group. Bifidobacteria and Clostridium cluster I colonization increased over time in the PF group but decreased in the SF and BF groups. Bifidobacteria had a protective role in RIs, whereas Clostridium cluster I was associated with atopy protection. Conclusion: The early administration of PF protects against RIs and mediates a species-specific modulation of the intestinal microbiota. Trial registration: clinicaltrial.gov Identifier: NCT02116452.

Economic evaluation of a 100% whey-based partially hydrolyzed infant formula in the prevention of atopic dermatitis among Swiss children

OBJECTIVE

A pharmacoeconomic analysis was undertaken to determine costs, consequences, and cost-effectiveness of a partially hydrolyzed 100% whey-based infant formula, NAN-HA®, manufactured by Nestlé S.A, Switzerland (PHF-W), branded under BEBA HA® in Switzerland, in the prevention of atopic dermatitis (AD) in 'at risk' Swiss children when compared to standard cow's milk formula (SF).

METHODS

Based on a 12-month time horizon including 6 months of formula consumption, an economic model was developed synthesizing treatment pathways, resource utilization, and costs associated with the treatment of AD in healthy 'at risk' Swiss newborns who could not be exclusively breastfed. Model inputs were retrieved from the literature, official formularies, and expert opinion. The treatment pathways considered a medical treatment approach, supplemented in some instances by a change of formula. The final outcome was the expected cost per avoided case of AD, yielding an incremental cost effectiveness ratio (ICER) for PHF-W vs SF. Outcomes were presented from three perspectives: the Swiss public healthcare system (MOH), the subject's family, and society (SOC). A secondary analysis compared PHF-W to whey-based extensively hydrolyzed formula (EHF) in prevention.

RESULTS

The model yielded 1653 avoided AD cases by selecting PHF-W over SF in a birth cohort of 22,933 'at risk' infants. The base case analyses generated an expected ICER of CHF 982 from the MOH perspective as well as savings of CHF 2202 and CHF 1220 from the family and SOC perspectives, respectively. PHF-W yielded CHF 11.4M savings against EHF when the latter was assumed to be used in prevention. One-way and probabilistic sensitivity analyses confirmed the robustness of the model.

CONCLUSION

Under a range of assumptions, this analysis has established the dominance from the family and societal perspectives and cost-effectiveness from the MOH perspective of PHF-W vs SF in the prevention of AD among 'at risk' Swiss infants.

Cost-effectiveness of partially-hydrolyzed formula for prevention of atopic dermatitis in Australia

OBJECTIVE

To perform an economic evaluation of a specific brand of partially hydrolyzed infant formula (PHF-W) in the prevention of atopic dermatitis (AD) among Australian infants.

METHODS

A cost-effectiveness analysis was undertaken from the perspectives of the Department of Health and Aging (DHA), of the family of the affected subject and of society as a whole in Australia, based on a decision-analytic model following a hypothetical representative cohort of Australian newborns who are not exclusively breastfed and who have a familial history of allergic disease (i.e., are deemed 'at risk'). Costs, consequences, and incremental cost-effectiveness ratios (ICER) were calculated for PHF-W vs standard cow's milk based infant formula (SF), and, in a secondary analysis, vs extensively hydrolyzed infant formula (EHF-Whey), when the latter was used for the prevention of AD.

RESULTS

From a representative starting cohort of 87,724 'at risk' newborns in Australia in 2009, the expected ICERs for PHF-W vs SF were AU$496 from the perspective of the DHA and savings of AUD1739 and AU$1243 from the family and societal perspectives, respectively. When compared to EHF-Whey, PHF-W was associated with savings for the cohort of AU$5,183,474 and AU$6,736,513 from the DHA and societal perspectives.

LIMITATIONS

The generalizability and transferability of results to other settings, populations, or brands of infant formula should be made with caution. Whenever possible, a conservative approach directing bias against PHF-W rather than its comparators was applied in the base case analysis. Assumptions were verified in one-way and probabilistic sensitivity analyses, which confirmed the robustness of the model.

CONCLUSIONS

PHF-W appears to be cost-effective when compared to SF from the DHA perspective, dominant over SF from the other perspectives, and dominant over EHF-Whey from all perspectives, in the prevention of AD in 'at risk' infants not exclusively breastfed, in Australia.

Economic evaluation of a 100% whey-based partially hydrolyzed infant formula in the prevention of atopic dermatitis among Danish children

OBJECTIVE

A pharmacoeconomic analysis was undertaken to determine costs, consequences, and cost-effectiveness of a brand of partially hydrolyzed 100%-whey formula manufactured by Nestlé (PHF-W), in the prevention of atopic dermatitis (AD) in 'at risk' Danish children compared to extensively hydrolyzed formula (EHF-Whey or Casein).

METHODS

Given the non-significant differences between PHF-W and EHF, the base case analytic approach amounted to a cost-minimization analysis (CMA) reporting the difference in formula acquisition costs over the period of formula consumption for the population of interest. However, sensitivity analyses (SAs) were undertaken to explore applying the nominal efficacy of PHF-W and EHF, thus leading to a cost-effectiveness analysis (CEA). Hence, an economic model based on a 12-month time horizon was developed synthesizing treatment pathways, resource utilization, and costs associated with the treatment of AD in the population of interest. The final economic outcome of the SAs was the incremental cost per avoided case (ICER) defined as the expected cost per avoided case of AD for PHF-W vs EHF, determined from three perspectives: the Ministry of Health (MOH), the family of the subject, and society (SOC).

RESULTS

In the base case CMA, savings of DKK 9 M, DKK 20 M, and DKK 29 M were generated for PHF-W vs EHF from the MOH, family, and SOC perspectives. In the sensitivity CEA, PHF-W was dominant over EHF-Whey from all perspectives, while EHF-Casein displayed against PHF-W unattractive ICERs of DKK 315,930, DKK 408,407, and DKK 724,337 from the MOH, family, and SOC perspectives. Probabilistic SAs indicated that PHF-W was 86% likely to be dominant over EHF-Whey, whereas EHF-Casein had no likelihood of dominating PHF-W.

CONCLUSION

Under a range of assumptions, this analysis demonstrated the attractiveness of PHF-W vs both types of EHF in the prevention of AD among 'at risk' Danish infants who are not or cannot be exclusively breastfed.

NIAID-sponsored 2010 guidelines for managing food allergy: applications in the pediatric population

Data from many studies have suggested a rise in the prevalence of food allergies during the past 10 to 20 years. Currently, no curative treatments for food allergy exist, and there are no effective means of preventing the disease. Management of food allergy involves strict avoidance of the allergen in the patient's diet and treatment of symptoms as they arise. Because diagnosis and management of the disease can vary between clinical practice settings, the National Institute of Allergy and Infectious Diseases (NIAID) sponsored development of clinical guidelines for the diagnosis and management of food allergy. The guidelines establish consensus and consistency in definitions, diagnostic criteria, and management practices. They also provide concise recommendations on how to diagnose and manage food allergy and treat acute food allergy reactions. The original guidelines encompass practices relevant to patients of all ages, but food allergy presents unique and specific concerns for infants, children, and teenagers. To focus on those concerns, we describe here the guidelines most pertinent to the pediatric population.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.

Economic evaluation of a 100% whey-based, partially hydrolysed formula in the prevention of atopic dermatitis among French children

OBJECTIVE

A pharmacoeconomic analysis was performed to determine costs, consequences and cost effectiveness of a partially hydrolysed 100% whey-based infant formula, NAN HA, manufactured by Nestlé S.A, Switzerland (PHF-W) and branded under Nidal Excel HA in France, in the prevention of atopic dermatitis (AD) in 'at risk' children when compared to standard cows' milk formula (SF) in France.

METHODS

A decision-analytic economic model depicting AD treatment pathways, as well as resource utilisation and costs associated with the treatment of AD in healthy yet 'at risk' French newborns who cannot be exclusively breastfed was constructed for a 12-month time horizon, including an initial 6 months of intervention with formula consumption. Model inputs were based on the literature, official formularies and expert opinion. The modelled treatment pathways included a dietary management approach (formula change), a medical treatment approach and a combination thereof. The final outcome was the expected cost per avoided case of AD, yielding an incremental cost per avoided case (ICER) of AD when comparing subjects who used PHF-W versus SF. Outcomes were presented from three perspectives: the French Ministry of Health (MOH), the subjects' family and society as a whole. A secondary analysis also compared PHF-W to extensively hydrolysed formula (EHF) in prevention.

RESULTS

The number of avoided AD cases by selecting PHF-W over SF was 13,356 cases in a birth cohort of 185,298 'at risk' infants. The base case analysis, at 65% reimbursement, yielded expected ICERs of €1343, € -624 (savings) and €719 from the MOH, family and societal perspectives, respectively. From all three perspectives, the highest cost was attributable to formula. In case of a 35% reimbursement rate for PHF-W, the ICER was €615 from the MOH perspective, while the use of PHF-W was cost neutral at 10% reimbursement. PHF-W was cost-saving against EHF (€98-€116 million savings depending on type of EHF), when this latter was used in prevention. One-way and probabilistic sensitivity analyses confirmed the robustness of the model.

CONCLUSION

Under a certain range of assumptions, this analysis based on predictive modelling has established the cost effectiveness of PHF-W in the prevention of AD in infants.

Partially hydrolyzed 100% whey protein infant formula and reduced risk of atopic dermatitis: a meta-analysis

OBJECTIVE

A reduced risk of atopic dermatitis (AD) among healthy infants who received 100% whey protein partially hydrolyzed formula (PHF-W) compared with intact protein cow's milk formula (CMF), has been reported in several studies. To validate these observations and estimate the magnitude of this potential association with greater statistical precision, we conducted a meta-analysis of clinical trial and intervention studies.

MATERIALS AND METHODS

A total of 18 articles representing 12 independent study populations met our inclusion criteria.

RESULTS

A statistically significant 44% (summary relative risk estimate [SRRE] = 0.56, 95% confidence interval 0.40-0.77) reduced risk of atopic manifestations, which included AD, was found among infants receiving PHF-W compared with infants receiving CMF. In a subanalysis of 4 studies that reported results specifically for AD and that were considered of superior methodological quality, the incidence of AD was reduced by 55% (SRRE = 0.45, 95% confidence interval 0.30-0.70).

CONCLUSIONS

Regardless of study design, infant population, follow-up time, or study location, individual study findings were consistent because a reduced incidence of AD was reported in all of the reviewed studies. Exclusive breast-feeding should be encouraged as the standard for infant nutrition in the first months of life. For infants who are not exclusively breast-fed, feeding with PHF-W instead of CMF reduces the risk of AD in infants, particularly in infants with a family history of allergy.

What is "high risk?" a systematic review of atopy risk and implications for primary prevention

Atopic diseases are common and becoming more prevalent. Efforts have focused on primary disease prevention by identifying high-risk children and applying preventative strategies. Our aim was to evaluate methods used to identify high-risk children in atopy prevention studies. A literature search for relevant articles published between 1986 and 2006 was conducted, and all abstracts were reviewed. The search yielded 1,535 publications, 133 were reviewed in detail, and 57 met inclusion criteria. High risk was defined by 30 different methods. First-degree relatives with an atopic disorder were included in all methods, but only three publications used referenced questionnaires to determine this. Less frequently included were cord blood immunoglobulin E measurements and skin prick or radioallergosorbent testing, and 16 methods relied on history alone. Family history was the most common method used to predict high risk of atopic disease in a child, but a minority of studies used a tested questionnaire to determine the presence of atopy in family members. The methods used to identify high-risk children are variable, and the development and widespread use of a validated, practical screening tool is needed.

Allergy in bakers’ apprentices and factors associated to non-participation in a cohort study of allergic sensitization

OBJECTIVE

To describe the prevalence of atopy and respiratory symptoms among baker apprentices at the start of the education and factors associated with non-participation in the study.

METHODS

A total of 346 students, 22.1(0.6) years of age, mean (SD), from the food production programme of technical colleges in Denmark were invited to participate in a 3 year study. Of the students, 187 agreed to participate and filled in a physician-administered questionnaire. The presence of atopy was determined by skin prick test (SPT) and serum allergen specific IgE (SpIgE). Bronchial hyper responsiveness to methacholine (PD(20) <or= 1,440 microg) was determined.

RESULTS

Prevalence of atopy was 32%. The prevalence of symptoms from the lungs and nose was 19.8 and 25.5%, respectively. Significantly, more SPT reactions were seen in males compared to females (39 vs. 22%, P < 0.05). Sensitization towards flour was significantly more frequent if determined as SpIgE (7.3%) compared to SPT (0.5%). We found a positive association between atopy and lung symptoms OR 6.1 (2.8-13.2 SD) and nasal symptoms OR 3.7 (1.8-7.5 SD). The major reason for non-participation was fear of blood sampling (25.5%).

CONCLUSION

The prevalence of atopy in bakers' apprentices was of the same magnitude in the general Danish population. Significantly, more male bakers' apprentices had atopy. This finding has major impact on the diagnostic procedures of occupational allergy in bakery workers emphasizing the need for standardization of the clinical tests. The main reasons for non-participation were, fear of blood-sampling (57%) and the 3 years commitment to the follow-up study (39%).

Are maternal psychosocial factors associated with cord immunoglobulin E in addition to family atopic history and mother immunoglobulin E?

BACKGROUND

Atopy in maternal and family histories is known to be a risk factor for elevated umbilical cord immunoglobulin E (cIgE). However, the association between cIgE and psychosocial factors remains under investigation.

OBJECTIVE

To explore whether psychosocial factors in addition to atopy contribute to elevated cIgE.

METHODS

Four private maternity hospitals fitting the quantile levels of SO(2) in 2000 cooperated with us by recruiting participants for this study: pairs of mothers and neonates living within 3-km catchment areas of air-monitoring stations. We used a questionnaire to collect exposure data, and the Pharmacia UniCap IgE assay test system to determine the levels of IgE in gravidas and cord blood.

RESULTS

Between July 2001 and March 2003, 334 mother and neonate pairs participated in this study. The frequencies of sensitization, serum IgE (sIgE)>100 IU/mL, or cIgE> or =0.35 IU/mL were not different between the four different hospitals. By multi-variate logistic regression analysis adjusted for environmental factors, genetic factors, and psychosocial factors, the risk factors for elevated cIgE were being a male neonate (odds ratio (OR)=3.5, 95% confidence interval (CI)=[1.5, 8.5]), carpets at home (OR=3.0, 95% CI=[1.02, 8.4]), maternal allergy to dog dander (OR=9.7, 95% CI=[1.2, 98.8], maternal total serum IgE>100 IU/mL (OR=5.1, 95% CI=[2.2, 12.8]), maternal regularly/mostly/often self-reported nervousness (OR=4.0, 95% CI=[1.3, 12.8]), family income 11,574-17 361 US dollars/year (OR=3.7, 95% CI=[1.3, 11.5]), incense burning (OR=4.0, 95% CI=[1.4, 13.3]), and atopy in maternal grandparents (OR=4.8, 95% CI=[1.7, 14.0]). By principle component analysis and logistic regression, psychosocial stress (beta +/- standard error=0.26+/-0.13, P=0.04) was associated with increased cIgE.

CONCLUSION

Psychosocial factors are potentially important risk factors for elevated cIgE.

Immune and airway effects of house dust mite aeroallergen exposures during postnatal development of the infant rhesus monkey

BACKGROUND

The effect of chronic environmental aeroallergen exposure on the immune system and airways has not been experimentally defined in very young children.

OBJECTIVE

The purpose of this study was to determine the immunophenotype of peripheral blood and airway leucocytes in the newborn rhesus macaque monkey, following recurrent aerosol exposure to house dust mite (HDM) (Dermatophagoides farinae).

METHODS

A regimen of HDM aerosolization was initiated for 2 h per day, three times per week, starting when rhesus macaque monkeys were 1 week of age. All monkeys were inoculated with diptheria, tetanus, and acellular pertussis vaccine at 5 weeks of age to simulate human infant vaccination schedules.

RESULTS

Following 8 weeks of HDM aeroallergen exposure, infant monkeys exhibited a significant reduction in the total peripheral blood lymphocyte numbers and a decreased frequency of peripheral blood CD4+ T lymphocytes with a CD45RA-'memory' immunophenotype. Lavage CD4+ T lymphocytes from HDM-exposed monkeys showed elevated expression of CD25, as well as an increase in CD45RA-/CD62L-/CD11ahigh immunophenotype. Eosinophils were more abundant within airways of HDM-exposed monkeys, accumulating maximally within the trachea.

CONCLUSION

These data demonstrate the development of immunological responses following chronic inhalation of a common environmental allergen during postnatal maturation in the non-human primate.

Early sensitisation and development of allergic airway disease - risk factors and predictors

The development and phenotypic expression of allergic airway disease depends on a complex interaction between genetic and several environmental factors, such as exposure to food, inhalant allergens and non-specific adjuvant factors (e.g. tobacco smoke, air pollution and infections). The first months of life seem to be a particularly vulnerable period and there is evidence that sensitisation is related to the level of allergen exposure during early life. At present, the combination of atopic heredity and elevated cord-blood IgE seems to result in the best predictive discrimination as regards development of allergic disease at birth. Early sensitisation, cow's milk allergy and atopic eczema are predictors for later development of allergic airway disease. Exposure to indoor allergens, especially house dust mite allergens, is a risk factor for sensitisation and development of asthma later in childhood in high-risk infants and infants with early atopic manifestations.

Therapeutic modalities for cow's milk allergy

OBJECTIVE

To discuss current therapeutic modalities for cow's milk allergy and its prevention.

DATA SOURCES AND STUDY SELECTION

The sources of data include original clinical studies carried out at Ste. Justine Hospital, as well as a systematic search of the published English and French language scientific literature restricted to human subjects using computerized searches (National Public Library of Medicine, Cochrane Database Systems Review) from 1997 to 2002. Search terms for article retrieval included food allergy, milk allergy, therapy, and prevention.

CONCLUSIONS

The therapy of food allergies depends upon an accurate diagnosis, which remains a challenge in non--IgE-mediated cases. Dietary exclusion remains the mainstay of therapy, with medications reserved for exceptional patients. Preliminary evidence suggests that pancreatic enzyme supplementation may be of benefit for cases with multiple food allergies and severe eczema. Hydrolysate formula use is currently recommended for dietary allergy prevention in infants at an increased risk when maternal milk is insufficient or unavailable. The use of partially hydrolyzed formulas to prevent allergic disorders, including atopic dermatitis, is supported by clinical studies, but cannot be used in the already sensitized, milk-allergic child. Probiotics show enormous potential in preventing food allergic disorders as well.

Heredity, pet ownership, and confounding control in a population-based birth cohort

BACKGROUND

The association between pet ownership in childhood and subsequent allergic disease is controversial. Bias related to selection of pet exposure has been suggested as a reason for contradictory study results.

OBJECTIVE

The purpose of this investigation was to elucidate how pet exposure depends on family history of allergic disease, smoking, and socioeconomic factors in a prospective birth cohort.

METHODS

Parents of 4089 two-month-old children answered a questionnaire that included detailed questions about family history of asthma (maternal, paternal, and sibling), rhinoconjunctivitis, atopic eczema/dermatitis syndrome, pollen and pet allergy, smoking habits, parental occupation, and family pet ownership (cat and dog). Dust samples collected from the mothers' beds were analyzed for Fel d 1 and Can f 1 in a subgroup of the cohort.

RESULTS

Cats were less frequently kept in families with parental asthma, rhinoconjunctivitis, or pet or pollen allergy (3.5% to 5.8%) than in families without parental allergic disease (10.8% to 11.8%). Dogs were less common in families with (3.3%) than in families without (5.9%) parental atopic eczema/dermatitis syndrome. Families with smoking mothers and those with low socioeconomic index kept cats and dogs more frequently. Cat allergen levels were lower in homes with than in homes without maternal pet allergy, and this tended to hold true even for homes without a cat. Cat ownership decreased from birth to 2 years of age, especially in families with parental history of allergic diseases.

CONCLUSION

There seems to be a selection of pet exposure based on parental history of allergy, maternal smoking, and socioeconomic factors. This has to be taken into consideration in evaluations of risk associations between pet exposure and allergic disease in childhood.

Food allergies

Adverse reactions to foods are commonly implicated in the causation of ill health. However, foreign antigens, including food proteins and commensal microbes encountered in the gastrointestinal tract, are usually well tolerated. True food allergies, implying immune-mediated adverse responses to food antigens, do exist, however, and are especially common in infants and young children. Allergic reactions to food manifest clinically in a variety of presentations involving the gastrointestinal, cutaneous, and respiratory systems and in generalized reactions such as anaphylaxis. Both IgE-mediated and non-IgE-mediated immune mechanisms are recognized. Important advances in the clinical features underlying specific food hypersensitivity disorders are reviewed.

Childhood risk factors for atopy and the importance of early intervention

The increasing prevalence of atopic diseases, particularly atopy-associated asthma, has become a major challenge for allergists and public health authorities in many countries. The understanding of the natural history of the atopic march, including the determinants that are modifiable and might become candidates for preventive intervention, is still very limited. Information provided by cross-sectional studies can only generate hypotheses, which need to be supported by prospective, longitudinal, cohort studies. Ultimately, it will depend on the results of well-controlled intervention studies to identify which nutritional, environmental, or lifestyle-related factors should be considered for early intervention and might be useful to reverse the epidemiologic trend.