Prevention of eczema

Prevalence of food allergen and aeroallergen sensitization among children in Sichuan province

Food allergen and aeroallergen sensitization are common allergic diseases worldwide, with widely varying estimates of prevalence in children. Our study investigated the characteristics of ingestion and inhalation allergy among children from Sichuan province in Southwest China, so as to get public awareness of these disorders.A total of 1722 children between 0 and 14 years' old were enrolled in this study. They were outpatients in the West China Second University Hospital during June 2019 to September 2019. Serum specific IgE specific to 10 types of food allergen and 10 types of aeroallergen were estimated. Nutrition indicators were tested by electrochemical luminescence.59.70% children were allergic to at least 1 allergen, comprising 24.90% to aeroallergen and 38.81% to food allergen, respectively, whereas 36.28% children were allergic to both aeroallergen and food allergen. Milk was the most common food allergen, and egg came in second place. With regard to aeroallergen, house dust mite held the maximum proportion (65.02%), whereas dust mite followed behind. Inhalation allergy was more commonly seen in boys than girls. Bronchitis was the most common symptom of both allergies. In addition, the highest incidence age for children to be sensitive to food allergen and aeroallergen were 0∼2 years' old and 3∼5 years' old, respectively. It is worth mentioning that there was no significant difference in nutritional status between children with or without allergic diseases.Our findings reveal that milk, egg, house dust mite, and dust mite are the most common allergens among children in Sichuan province. Boys are more susceptible to aeroallergen than girls. Furthermore, the prevalence of ingestion and inhalation allergy varies from different age groups, and has no correlation with nutritional status. In brief, the analysis of the pattern of food allergen and aeroallergen sensitization is invaluable to effective diagnosis and treatment of allergic diseases.

What are the risks associated with formula feeding? A re-analysis and review

BACKGROUND

Most infant feeding studies present infant formula use as "standard" practice, supporting perceptions of formula feeding as normative and hindering translation of current research into counseling messages supportive of exclusive breastfeeding. To promote optimal counseling, and to challenge researchers to use exclusive breastfeeding as the standard, we have reviewed the scientific literature on exclusive breastfeeding and converted reported odds ratios to allow discussion of the "risks" of any formula use.

METHODS

Studies indexed in PubMed that investigated the association between exclusive breastfeeding and otitis media, asthma, types 1 and 2 diabetes, atopic dermatitis, and infant hospitalization secondary to lower respiratory tract diseases were reviewed. Findings were reconstructed with exclusive breastfeeding as the standard, and levels of significance calculated.

RESULTS

When exclusive breastfeeding is set as the normative standard, the re-calculated odds ratios communicate the risks of any formula use. For example, any formula use in the first 6 months is significantly associated with increased incidence of otitis media (OR: 1.78, 95% CI: 1.19, 2.70 and OR: 4.55, 95% CI: 1.64, 12.50 in the available studies; pooled OR for any formula in the first 3 mo: 2.00, 95% CI: 1.40, 2.78). Only shorter durations of exclusive breastfeeding are available to use as standards for calculating the effect of "any formula use" for type 1 diabetes, asthma, atopic dermatitis, and hospitalization secondary to lower respiratory tract infections.

CONCLUSIONS

Exclusive breastfeeding is an optimal practice, compared with which other infant feeding practices carry risks. Further studies on the influence of presenting exclusive breastfeeding as the standard in research studies and counseling messages are recommended.

Exclusive breastfeeding and incident atopic dermatitis in childhood: a systematic review and meta-analysis of prospective cohort studies

BACKGROUND

Breastfeeding is undisputedly preferable to formula feeding for infant nutrition because of its nutritional, immunological and psychological benefits. However, studies on the association between breastfeeding and development of atopic dermatitis (AD) have shown inconsistent results.

OBJECTIVES

To examine the association between exclusive breastfeeding for at least 3 months after birth and the development of AD in childhood.

METHODS

An electronic literature search of MEDLINE (January 1966-May 2008) and EMBASE (1980-May 2008) was conducted. Prospective cohort studies that met the predetermined criteria were independently assessed by three reviewers. The pooled effect estimate was calculated by random effects model. Heterogeneity across the studies was investigated by meta-regression analysis.

RESULTS

Twenty-one studies with 27 study populations were included for meta-analysis. The summary odds ratio (OR) for the effect of exclusive breastfeeding on the risk of AD was 0.89 (95% confidence interval, CI 0.76-1.04). Heterogeneity was found across the studies (chi(2) = 83.6, d.f. = 26; P < 0.001). Breastfeeding was associated with a decreased risk of AD (OR 0.70; 95% CI 0.50-0.99) when analysis was restricted to the studies comparing breastfeeding with conventional formula feeding. The pooled OR for study populations with atopic heredity was 0.78 (95% CI 0.58-1.05).

CONCLUSIONS

There is no strong evidence of a protective effect of exclusive breastfeeding for at least 3 months against AD, even among children with a positive family history.

Exclusive breastfeeding and risk of atopic dermatitis in some 8300 infants

Earlier studies on breastfeeding and atopy in infants have yielded contradictory results. We examined the relationship between exclusive breastfeeding and atopic dermatitis (AD) in a cohort of infants born between 1 October 1997 and 1 October 1999 in south-east Sweden. We evaluated the risk of AD 'at least once' or 'at least three times' during the first year of life in relation to duration of exclusive breastfeeding: <4 months (short exclusive breastfeeding; SEBF) vs. > or = 4 months. All data were obtained through questionnaires. Of 8346 infants with breastfeeding data, 1943 (23.3%) had suffered from AD during the first year of life. Duration of exclusive breastfeeding was not associated with lower risk of AD (p = 0.868). SEBF did not influence the risk of any AD (OR = 1.03; 95% CI OR = 0.91-1.17; p = 0.614) or AD at least three times (OR = 0.97; 95% CI OR = 0.81-1.16; p = 0.755) during the first year of life. Adjustment for confounders did not change these point estimates. Neither was there any link between SEBF and risk of AD among infants with a family history of atopy [adjusted odds ratio (AOR) = 1.16; 95% CI AOR = 0.90-1.48; p = 0.254]. Furred pets at home were linked to a lower risk of AD both among infants with a family history of atopy (AOR = 0.76; 95% CI AOR = 0.60-0.96; p = 0.021) and among infants with no such history (AOR = 0.79; 95% CI AOR = 0.69-0.90; p < 0.001). Infants with no family history of atopy were less prone to develop AD if parents smoked (AOR = 0.76; 95% CI AOR = 0.61-0.95; p = 0.016). This study indicates that exclusive breastfeeding does not influence the risk of AD during the first year of life, while presence of furred pets at home seems to be negatively associated with AD.

Isoflavones in soy infant formula: a review of evidence for endocrine and other activity in infants

Soy infant formulas are widely used, but few studies have evaluated long-term safety or examined specific forms of toxicity, such as to the endocrine or immune systems. This review focuses on newer experimental studies of the effects on estrogen activity, immune function, and thyroid economy of genistein and daidzein, two isoflavones in soy infant formula, and existing human studies of soy formula use. In order to judge the likelihood that an endpoint seen in laboratory studies might occur in soy-fed infants, we examined the doses and the resulting serum or plasma concentrations from the laboratory studies and compared them with doses and concentrations seen in soy-fed infants. We also summarized the estimates of the potency of the isoflavone compounds relative to estradiol. Given the scarcity and inconsistency of existing human data and the substantial laboratory evidence of hormonal and other activity at doses relevant to the soy-fed infant, we conclude that more clinical and epidemiological study is warranted.

Breast-feeding and the onset of atopic dermatitis in childhood: a systematic review and meta-analysis of prospective studies

BACKGROUND

Despite the numerous studies on the possible protective effect of breast-feeding against the onset of atopic dermatitis during childhood, this issue remains controversial.

OBJECTIVE

We conducted a systematic review with meta-analysis of prospective studies that evaluated the association between exclusive breast-feeding during the first 3 months after birth and atopic dermatitis.

METHODS

A comprehensive search of the 1966-2000 MEDLINE database and review of the reference lists of relevant articles identified 18 prospective studies that met the predefined inclusion criteria. By means of a standardized approach, 2 of the investigators independently assessed the methodologic quality of the studies, duration and exclusivity of breast-feeding, outcome measures, and control for potential confounding factors. The same approach was applied during data abstraction and evaluation of the estimates of association. Summary measures of association were then calculated.

RESULTS

The summary odds ratio (OR) for the protective effect of breast-feeding in the studies analyzed was 0.68 (95% confidence interval [CI], 0.52-0.88). This effect estimate was higher in the group of studies wherein children with a family history of atopy were investigated separately (OR = 0.58; CI, 0.41-0.92) than in those of combined populations (OR = 0.84; CI, 0.59-1.19). A small subset of studies of children without a history of atopy in first-degree relatives showed no association between breast-feeding and the onset of atopic dermatitis (OR = 1.43; CI, 0.72-2.86).

CONCLUSION

Exclusive breast-feeding during the first 3 months of life is associated with lower incidence rates of atopic dermatitis during childhood in children with a family history of atopy. This effect is lessened in the general population and negligible in children without first-order atopic relatives. Breast-feeding should be strongly recommended to mothers of infants with a family history of atopy, as a possible means of preventing atopic eczema.

Effectiveness of laundry washing agents and conditions in the removal of cat and dust mite allergen from bedding dust

BACKGROUND

There is limited information about the removal of allergens by laundry washing.

OBJECTIVE

The purpose of this investigation was to determine the dynamics of the removal of mite allergen (Der p 1) and cat allergen (Fel d 1) from bed dust during simulated laundry processes.

METHODS

Three studies were performed. The first compared combinations of 4 laundry agents (water alone, soap, detergent with enzymes, and detergent without enzymes), 4 temperatures (15 degrees, 25 degrees, 45 degrees, and 60 degrees C), and 3 extraction times (5, 20, and 60 minutes). The second study examined allergen extraction by 11 common brands of detergents at 25 degrees and 45 degrees C for 5 minutes. The third study compared 4 detergents containing enzymes before and after the denaturation of their enzymes. To measure the quantity of allergens extracted, each study used an ELISA assay as well as a more sensitive but semiquantitative Halogen immunoassay to detect any allergens remaining after the simulated laundry extraction.

RESULTS

Study 1 showed that detergents extracted more of both Fel d 1 and Der p 1 than either soap or water alone and that almost all allergens were extracted within 5 minutes at 25 degrees. However, washing at 60 degrees C extracted slightly more Fel d 1 and denatured Der p 1, resulting in lower residual amounts of both allergens. Study 2 showed that all of the commercial detergents performed similarly. Study 3 showed that the presence of enzymes in detergent formulations did not produce a significant effect on the extraction of allergens.

CONCLUSION

Using detergent solutions at 25 degrees for at least 5 minutes was sufficient to extract most mite and cat allergen from dust of bedding.

Breast feeding and later psychosocial adjustment

The relationship between the duration of breast feeding and psychosocial outcomes measured between the ages of 15 and 18 years was examined in a birth cohort of 999 New Zealand children. During the period from birth to 1 year, information was collected on maternal breast-feeding practices. Between the ages of 15 and 18 years, sample members were assessed using a range of psychosocial measures, including measures of the quality of parent-child relationships, juvenile delinquency, substance abuse and mental health. Children who were breast fed for a longer duration were more likely to report higher levels of parental attachment and tended to perceive their mothers as being more caring and less overprotective towards them compared with bottle-fed children. No association was found between the extent of breast feeding and subsequent rates of juvenile offending, substance use and mental health in later life. Mothers who elected to breast feed were also more likely to be older, better educated, living with a partner, less likely to smoke during pregnancy, and to come from advantaged socio-economic backgrounds characterised by better living standards and a higher family income. Rates of breast feeding were also greater among mothers who gave birth to a first-born child of higher birthweight. After adjustment for these maternal and perinatal factors, the duration of breast feeding remained significantly associated with adolescent perceptions of maternal care, with increasing duration of breast feeding being associated with higher levels of perceived maternal care during childhood. It is concluded that: (a) it is unlikely that breast feeding is associated with reduced risks of psychiatric disorder in later life; (b) breast feeding may lead to closer parent-child relationships; and (c) it is unlikely that the association between breast feeding and cognitive development is mediated by intervening processes relating to improved psychosocial adjustment in breast-fed children.

Soy allergy is not common in atopic children: a multicenter study

The aim of the present study was to evaluate the prevalence of soy allergy (positive skin test and positive challenge test) in a large cohort of atopic children, many of them soy fed early in life for several months. In order to investigate the prevalence of soy allergy, two groups of children were enrolled into the study. The first group comprised a cohort of 505 children with personal history suggestive of food allergy. The second group included 243 children born of atopic parents, who had been soy protein formula fed for the first six months of life for the prevention of cow's milk allergy and who had been prospectively followed up, from birth to 5 years. As regards the prevalence of soy allergy in the cohort of children suffering from allergic disease: 31/505 children (6%) had positive skin prick test to soy, however only six of the 31 children with positive skin prick test to soy had positive challenge test to soy. With regard to the prevalence of soy allergy in the children who had been soy protein formula fed in the first six months of life (second group): 14/243 children (6%) had positive skin prick test to soy, but the double blind placebo control oral food challenge to soy was positive in only one of these 14 children. In conclusion documented soy allergy is not common in atopic children.

Early solid food diet and eczema in childhood: a 10-year longitudinal study

The relationship between early solid feeding in the first four months and risks of eczema in childhood was examined in a birth cohort of 1265 children studied to the age of 10 years. The major findings of this analysis were: 1) children exposed to a diverse solid food diet during their first four months had risks of eczema in early childhood which were about 1.6 times those of children who were not introduced to solid food by age four months. These associations persisted when a range of confounding factors (including family history of atopic disease, infant milk diet (breast/bottle) and family social background factors) were taken into account. 2) Similar associations between early infant diet and risks of chronic and recurrent eczema up to the age of ten years were also found. It was estimated that after adjustment for confounding factors, children exposed to an early diverse solid food diet had risks of eczema which were over 2.5 times those of children not introduced to solid feeding. These results are generally consistent with the hypothesis that early exposure to a diverse solid food diet may increase risks of eczema in children who are susceptible to this condition.

Allergenicity and nutritional adequacy of soy protein formulas

Soy protein formulas are used for different conditions, including cow milk protein allergy, lactose and galactose intolerance, and severe gastroenteritis. Feeding soy protein formulas to normal term infants is associated with normal growth, normal protein nutritional status, and normal bone mineralization. Recent studies of infants fed soy protein formulas exclusively during the first months of life revealed no immunologic abnormality; however, the use of such formulas for management of cow milk protein allergy and for prevention of atopy is controversial. Although in the past decade many studies have stressed soy allergenicity, soy allergenicity has been confirmed by the challenge test in only a few studies. In this article we review the studies dealing with the allergenicity of soy protein formulas. We also present our own data on their use in the prevention and management of cow milk protein allergy.

Higher risk of infantile atopic dermatitis from maternal atopy than from paternal atopy

The risk of infantile atopic dermatitis (AD) posed by maternal atopy and paternal atopy, respectively, were compared in the infants from a birth cohort in whom one of the parents had been designated atopic by skin prick testing. Nineteen with atopic mothers were compared with 20 with atopic fathers. AD, other atopic manifestations and potentially influential factors such as breast-feeding were documented prospectively during the first year in all infants. At 3, 6 and 12 month assessments skin prick sensitivity and total serum IgE concentration were determined. Nine of 19 infants with atopic mothers and two of 20 with atopic fathers had AD (P = 0.023) giving a relative risk of 4.7 (95% confidence interval 2.5 to 9.0). Seven of 19 with atopic mothers and none with atopic fathers had AD with onset before 6 months (P = 0.007). When all types of disease evidence (AD, recurrent wheeze and food reactions) were analysed together no significant difference was apparent between the groups. The two groups were found to be well matched with regard to breast-feeding, time of starting cow's milk, solids and egg, sex, month of birth, parental AD and smoking, race, household pets and neonatal IgE concentration. IgE concentrations at each age and the prevalence of skin prick positivity were similar between the groups. Maternal atopy poses a higher risk for infantile AD and paternal atopy. Whether this may be due to genetic or congenital factors or both is uncertain, but clearly the finding is of relevance in the prediction of allergy in childhood.

Allergic symptoms up to 4-6 years of age in children given cow milk neonatally. A prospective study

In a previously published prospective study, we followed the development of allergic symptoms in term infants with a slightly reduced birthweight (-1 SD to -2 SD). These children received, according to local routine, early feeding with cow milk formula in order to diminish such neonatal problems as hypoglycemia and hyperbilirubinemia. Of 216 infants 207 were observed for allergic symptoms up to 18 months of age. One group (F) received cow milk formula during the first days of life before the mother's breastmilk production started and was then breastfed; the other (B) was not given any formula before normal breastfeeding started. Unexpectedly, we found fewer allergic symptoms, in particular allergic skin problems, in the group fed cow milk, the difference being concentrated to children with a family history of allergic symptoms. At 5 years of age 183 of the 207 children have been reinvestigated. Mild symptoms of allergy (suspected and obvious) were found in 22% (F) and 27% (B) respectively (NS). Moderate and severe symptoms of allergy (obvious) were found in 4.2% (F) and 4.5% (B). In the subgroup with a double family history of allergic symptoms, 28% (7/25, F) and 59% (10/17, B) had symptoms of allergy (p less than 0.05). This difference was even more pronounced when laboratory tests in favour of atopic diagnosis were included, 14% (F) and 53% (B) respectively (p less than 0.05). Thus at 5 years we still find a significantly lower frequency of allergic symptoms in the subgroup fed cow milk formula early with a family history of allergic symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Neonatal IgE: a poor screen for atopic disease

Screening for atopic disease using neonatal serum IgE has been advocated on the basis of the predictive value of elevated levels. However, this is only one measure of validity. The test was validated fully in 92 infants with a bi-parental history of atopy using 0.7 IU/ml as the cut-off. All infants were assessed prospectively for evidence of atopic disease (eczema, recurrent wheezing or food reactions) and skin-prick test positivity in the first year. Total serum IgE was measured by ultrasensitive ELISA on 61 cord blood samples and 92 samples taken at 7 days. All cord samples were re-analysed by PRIST and the first 33 by ultrasensitive RIA giving, respectively, 82% and 94% concordance (regarding undetectable, detectable and elevated levels) with ELISA. Maternal contamination was indicated in 7% of cord samples by high serum IgA. Ninety-five per cent of cord/7-day IgE pairs showed no change or minor rises at 7 days. Forty-nine per cent of the infants had evidence of atopic disease. Only 5% had elevated 7-day IgE. The positive and negative predictive values of the 7-day test were 60% and 52%, respectively, and specificity 96% but the sensitivity was only 7%. High levels did not distinguish the infants with the most unequivocal evidence of disease, i.e. eczema with a positive skin test. In conclusion IgE at 7 days is comparable to and more reliable than cord IgE. However, neonatal IgE screening is too insensitive to have clinical application.

The IgE and IgG subclass antibody response to foods in babies during the first year of life and their relationship to feeding regimen and the development of food allergy

This follow-up study of 191 babies investigated the development of food allergy in an unselected population and its relationship to total and antigen-specific IgE and IgG subclass levels. Sensitization to egg, as indicated by a positive skin test or RAST, was found in 5% of 1-year-old babies, but none of the babies in this series fulfilled the clinical criteria for immediate-type milk allergy. For both bovine casein (CAS) and egg albumin, the IgG response was largely restricted to IgG1 in contrast to the predominant IgG4 response to these antigens that is found in adults. The level of IgG4, but not IgG1, antibody to CAS and ovalbumin (OV) was lower in some of the babies compared with that of their mothers (N = 166; p less than 0.05, Student's paired t test). However, there was no difference in the total serum IgG subclass levels between mothers and babies. These results demonstrate that, in the population of babies studied, (1) type I hypersensitivity to egg occurred in 5% of 1-year-old babies, (2) the predominant IgG subclass of antibodies to CAS and OV in babies is IgG1, and (3) in the 22% of babies, there was substantially (greater than 1000-fold) less IgG4 antibody to CAS and OV than in their mothers, suggesting specific exclusion of some IgG4 antibodies.

Asthma, allergic rhinitis and atopic eczema in Finnish children and adolescents

The parents of 3649 Finnish children and adolescents were interviewed in 1980 to evaluate the prevalence of bronchial asthma, allergic rhinitis and atopic dermatitis. The same group was interviewed 6 years later to determine the incidence of new cases of bronchial asthma in the 1980s. Age- and sex-matched samples were taken from three areas, southern, eastern and northern Finland to allow assessment of possible regional differences in prevalences and incidences. The prevalences of atopic eczema, allergic rhinitis and asthma were 1.7%, 6.0% and 4.3%, respectively. These figures are similar to those found in previous studies in Scandinavia and Finland over 10 years ago. The prevalence of atopy was highest (6.4%) in southern Finland, which is the most urbanized area of our country. The prevalence of asthma was highest (3.3%) in northern Finland. This is still low when compared with the incidences in other European countries. THe prevalences of asthma and atopy were lowest in eastern Finland which is the most agrarian area. The incidence of asthma was 1.5 cases/1000 individuals/year, but regional differences were shown.

Atopy in children with and without a family history of atopy. I. Clinical manifestations, with special reference to diet in infancy

The influence of a family history of atopy on atopic morbidity, and relationships between diet in infancy and allergic manifestations at the ages of one and five years were prospectively studied in 91 children. A control group consisted of 72 children with no family history of atopy. At the age of one year, atopic manifestations were found in 19% of 163 children, in 23% of those with a family history of atopy and in 14% of those with no such history. Skin problems were more common in children with a family history of atopy (43%) than in the control children (19%). Of the children with a family history of atopy, 23% had prolonged rhinorrhoea during infancy. The corresponding figure in children with no family history of atopy was 10%. Prolonged rhinorrhoea during infancy correlated with parental smoking only in children with a family history of atopy (47% vs. 18%). At the age of five years, atopic disease was found in 17% of 128 children, 24% of those with a family history of atopy and 9% of those with no such history. Atopic eczema was more common in children with a family history of atopy, irrespective of the diet consumed during infancy. Atopic signs were found in about half of all the children with a family history of atopy. If atopy had been present in the family, the child usually exhibited the same manifestation. Onset of atopic manifestations was not prevented or delayed.

Influence of maternal diet during lactation and use of formula feeds on development of atopic eczema in high risk infants

OBJECTIVE

To examine the effects of maternal diet during lactation and the use of formula feeds on the development of atopic eczema in infants at risk.

DESIGN

Mothers who planned to breast feed exclusively were randomly allocated to either a restricted diet (avoiding milk and other dairy products, eggs, fish, peanuts, and soybeans) or a diet without restrictions. Mothers who did not plan to breast feed were randomly allocated to using one of three formula feeds.

SETTING

Child health centre in Canada.

SUBJECTS

97 Mothers who chose to breast feed and 124 mothers who did not.

INTERVENTIONS

Restricted diet for 49 mothers who breast fed. Casein hydrolysate formula, soy milk formula, or cows' milk formula for infants not breast fed.

MAIN OUTCOME MEASURE

Development of eczema in babies.

RESULTS

Infants were followed up over 18 months and examined for eczema. Eczema was less common and milder in babies who were breast fed and whose mothers were on a restricted diet (11/49 (22%) v 21/48 (48%)). In infants fed casein hydrolysate, soy milk, or cows' milk 9/43 (21%), 26/41 (63%), and 28/40 (70%), respectively, developed atopic eczema.

CONCLUSIONS

In families with a history of atopic disease [corrected] mothers who breast feed should avoid common allergenic foods during lactation. If they choose not to breast feed a hydrolysate formula should be used.

The Christchurch Child Development Study: a review of epidemiological findings

The Christchurch Child Development Study is a longitudinal study of a birth cohort of 1265 New Zealand children who have been studied over an 11-year period using data from multiple sources including parental interview, medical records, teacher questionnaires and direct testing of children. The article provides a review of the major lines of epidemiological research examined in the Study. These include: breast feeding and child health; parental smoking and child health; the effects of low level lead exposure; childhood asthma; nocturnal bladder control; the effects of early hospital admission; the distribution of child health services; and the consequences of private medical insurance. In addition a number of general topics (sample attrition, measurement error, individual differences and causal inference) relating to longitudinal designs are discussed briefly. It is concluded that the longitudinal design is a powerful and cost-effective method of gathering data for general paediatric epidemiological purposes but that research in this area would benefit from an increased use of emerging methods of statistical modelling.

Allergic diseases in Swedish school children

The occurrence of allergic diseases in children was studied on the basis of a questionnaire sent to the parents of 20,000 school children, 7, 10 and 14 years of age, in 3 parts of Sweden with different climatic conditions. The prevalence of asthma was 2.4%, allergic rhinoconjunctivitis 7.4%, eczema 7.8% and total allergic diseases 16.9%. The prevalence of all diseases was significantly higher in the northern part of the country than in the southern parts. This geographic variation was not related to heredity, infant feeding pattern or known exposure variables other than the cold and dry climate. Parental history of allergic diseases increased the incidence in the offspring 2-9 times, with a pattern of symptom specificity and a cumulative effect of double parental history. Breast-feeding postponed the onset of allergic disease only in children with double parental history.

Milk whey-specific immune complexes in allergic and non-allergic subjects

We developed an antigen- and isotype-specific ELISA for the rapid detection of native serum immune complexes (IC). It is a sandwich assay, in which a solid phase antigen-specific capture antibody selectively binds the antigen-specific IC via the antigen. The isotype of the bound IC is then identified using an enzyme-labelled indicator antibody. Using this sensitive assay system, we were able to detect native serum milk whey-specific immune complexes (SMIC) of the IgG, IgE and IgA isotypes. Detectable amounts of native serum SMIC of all three isotypes were found in sera of the majority of both atopic and non-atopic subjects. The ELISA was then used to compare the levels of native IgE SMIC in sera of milk RAST positive atopic patients with those found in milk RAST negative atopic patient sera. Milk RAST positive patient sera were found to have significantly higher mean levels (P less than or equal to 0.005) of native IgE SMIC than milk RAST negative sera. Sera of other atopic individuals were also found to contain significantly higher mean levels (P less than or equal to 0.005) of native IgG and IgA SMIC than non-atopic donors. IgE IC may specifically be involved in adverse symptoms seen in milk allergic patients.

An epidemiological study of atopy in children

A sample of 930 children, between 9 years and 15 years old from six Italian towns, were studied. Their family history of allergy, personal allergy and medical history, current allergy symptoms, exposure to environmental allergens, feeding as infants, and their parents' occupations were recorded. They were skin-prick tested (SPT) with a range of common allergens. A subject was defined as atopic if at least one SPT caused a weal greater than 3 mm diameter. The association between the recorded information and atopy was investigated by logistic multiple regression. Atopy was positively associated with: high density housing; medium or high exposure to environmental allergens; a history of rhinitis, asthma or atopic eczema; male gender; and a history of breastfeeding. It was independent of infectious diseases, vaccinations and operations, social class and family history. Thus, there was no evidence of a genetic factor in atopy, other than sex.

Cord serum IgE in relation to family history and as predictor of atopic disease in early infancy

Cord serum IgE was assayed by particle counting immunoassay (PACIA) in an unselected series of European newborns (n = 190; geom mean = 0.37 IU/ml) and a cut-off limit established (greater than or equal to 1.20 IU/ml) for prediction of atopy. At control follow-up by questionnaire 18 months after birth, 38 infants (20.0%) had developed definite (9.5%) or probable (10.5%) atopy with a significant predominance of boys (P less than 0.03). Infants with a positive immediate family history (IFH) had a higher risk of developing atopy (P less than 0.0025) and also had a higher incidence of elevated cord IgE (P less than 0.02) than infants with a negative IFH. Maternal atopy influenced cord IgE levels significantly (P less than 0.00005), whereas paternal atopy did not (P = 0.23). No fetal IgE antibodies against five common allergens could be demonstrated in 36 cord sera tested. Breast-feeding for 3 months was not sufficient to prevent atopic symptoms. The predictive value of cord IgE was high since 26 of 36 newborns (positive predictive value = 72.2%) with elevated cord IgE had developed atopic symptoms before follow-up. Of the 38 infants who developed atopic symptoms, 26 had elevated cord IgE (sensitivity = 68.4%) compared to only 10 (6.6%) of the 152 atopy-free infants (P less than 0.00005). The data indicate that elevated cord IgE as determined by PACIA is a good predictor of early-onset atopy, better than family history (P less than 0.008), and that primarily maternal atopy seems to affect fetal IgE synthesis.

Xenogeneic antibodies and atopic disease

Xenogeneic antibodies can survive food processing procedures with their biological activity intact and even enhanced. These antibodies can be absorbed from the human gut, and will function both as antigens and antibodies in the human immune system. Antibodies to bovine gamma globulins (BGG) have been detected in human sera and the family of anti-BGG antibodies must include anti-idiotypic antibodies, very low doses of which can influence the immune response. The hypothesis is that the human immune system may be primed by low-level exposure to xenogeneic antibodies specific for those human allergens which are ubiquitous in the farm environment, such as pollens, mites, and moulds, the result being a deleterious and inappropriate response on subsequent exposure to these allergens. Dairy products are the most important source of xenogeneic antibodies in the western diet, and the hypothesis may partly explain the association between cow's milk and allergies to substances other than milk proteins.

Atopic eczema and preterm birth

In a group of 443 children with atopic eczema there was a significant lack of subjects born before 37 weeks' gestation. It is possible that preterm birth reduces the chances of the subsequent development of severe atopic disease.

Does breast feeding help protect against atopic disease? Biology, methodology, and a golden jubilee of controversy

To help shed some light on the 50-year-old controversy concerning the possible protective effect of breast feeding on subsequent atopic disease, I developed 12 standards pertaining to both biologic and methodologic aspects of exposure (infant feeding), outcome (atopic conditions), and statistical analysis for studies of atopic eczema, asthma, allergic rhinitis, cow milk allergy, and other food allergy. Among the published studies on atopic eczema, the nine claiming a protective benefit of breast feeding performed less well than the 12 not making such a claim on "methodologic" standards relating to strict diagnostic criteria and blind ascertainment of outcome. The positive studies were somewhat stronger, however, on the "biologic" standards bearing on sufficient duration and exclusivity of breast feeding and on separate analysis of children at high risk. For the other atopic conditions, there were no important differences between positive and negative studies. In few negative or positive studies was there adequate control for confounding variables or examination of potential benefits relating to the severity or age at onset of atopic disease. To avoid another 50 years of unresolved controversy, future studies should improve both the biologic and methodologic aspects of their design and analysis.

Development of atopic disease after early administration of cow milk formula

We prospectively studied the incidence of atopic disease in healthy term infants with a birth weight between -1 and -2 SD who were fed a cow milk formula during the first few days of life. A total of 216 infants were randomized to receive either early feeding with formula before normal breastfeeding was started (n = 112) or "normal feeding" with breastmilk (n = 104). Symptoms of allergy developed in 18% of the infants before 18 months of age in the formula fed group, as compared to 33% in the breastfed group (P less than 0.05). The difference was confined to the group of infants with a history of allergy in two family members. Thus, 11% of the formula-fed infants developed allergy symptoms, as compared to 61% of the control infants (P less than 0.01). Our study implies that early feeding during the first days of life with a cow milk formula, before the introduction of breastmilk, may reduce the incidence of allergy symptoms before 18 months of age in infants with a family history of allergy.