***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The natural history of allergic sensitization is complex and poorly understood . A prospect i ve nonr and omized study was carried out in a population of asthmatic children younger than 6 years of age whose only allergic sensitivity was to house dust mites ( HDMs ) . OBJECTIVES The study was design ed to determine whether specific immunotherapy ( SIT ) with st and ardized allergen extracts could prevent the development of new sensitizations over a 3-year follow-up survey . METHODS We studied 22 children monosensitized to HDM who were receiving SIT with st and ardized allergen extracts and 22 other age-matched control subjects who were monosensitized to HDM .  The initial investigation included a full clinical history , skin tests with a panel of st and ardized allergens , and the measurement of allergen-specific IgE , depending on the results of skin tests . Children were followed up on an annual basis for 3 years , and the development of new sensitizations in each group was recorded . RESULTS Ten of 22 children monosensitized to HDM who were receiving SIT did not have new sensitivities compared with zero of 22 children in the control group ( p = 0.001 , chi square test ) . CONCLUSIONS This study suggests that SIT in children monosensitized to HDM alters the natural course of allergy in preventing the development of new sensitizations BACKGROUND The prevalence of peanut allergy appears to have increased in recent decades . Other than a family history of peanut allergy and the presence of atopy , there are no known risk factors . METHODS We used data from the Avon Longitudinal Study of Parents and Children , a geographically defined cohort study of 13,971 preschool children , to identify those with a convincing history of peanut allergy and the subgroup that reacted to a double-blind peanut challenge .  We first prospect ively collected data on the whole cohort and then collected detailed information retrospectively by interview from the parents of children with peanut reactions and of children from two groups of controls ( a r and om sample from the cohort and a group of children whose mothers had a history of eczema and who had had eczema themselves in the first six months of life ) . RESULTS Forty-nine children had a history of peanut allergy ; peanut allergy was confirmed by peanut challenge in 23 of 36 children tested . There was no evidence of prenatal sensitization from the maternal diet , and peanut-specific IgE was not detectable in the cord blood . Peanut allergy was independently associated with intake of soy milk or soy formula  ( odds ratio , 2.6 ; 95 percent confidence interval , 1.3 to 5.2 ) , rash over joints and skin creases ( odds ratio , 2.6 ; 95 percent confidence interval , 1.4 to 5.0 ) , and oozing , crusted rash ( odds ratio , 5.2 ; 95 percent confidence interval , 2.7 to 10.2 ) . Analysis of interview data showed a significant independent relation of peanut allergy with the use of skin preparations containing peanut oil ( odds ratio , 6.8 ; 95 percent confidence interval , 1.4 to 32.9 ) . CONCLUSIONS Sensitization to peanut protein may occur in children through the application of peanut oil to inflamed skin . The association with soy protein could arise from cross-sensitization through common epitopes . Confirmation of these risk factors in future studies could lead to new strategies to prevent sensitization in infants who are at risk for subsequent peanut allergy Background The value of allergen elimination diets during pregnancy for primary prevention of infant allergy has been question ed . However , dietary compliance may influence effectiveness BACKGROUND Children with allergic rhinitis are likely to develop asthma . OBJECTIVE The purpose of this investigation was to determine whether specific immunotherapy can prevent the development of asthma and reduce bronchial hyperresponsiveness in children with seasonal allergic rhinoconjunctivitis . METHODS From 6 pediatric allergy centers , 205 children aged 6 to 14 years ( mean age , 10.7 years ) with grass and /or birch pollen allergy but without any other clinical ly important allergy were r and omized either to receive specific immunotherapy for 3 years or to an open control group . All subjects had moderate to severe hay fever symptoms , but at inclusion none reported asthma with need of daily treatment . Symptomatic treatment was limited to loratadine , levocabastine , sodium cromoglycate , and nasal budesonide .  Asthma was evaluated clinical ly and by peak flow . Methacholine bronchial provocation tests were carried out during the season(s ) and during the winter . RESULTS Before the start of immunotherapy , 20 % of the children had mild asthma symptoms during the pollen season(s ) . Among those without asthma , the actively treated children had significantly fewer asthma symptoms after 3 years as evaluated by clinical diagnosis ( odds ratio , 2.52 ; P < .05 ) . Methacholine bronchial provocation test results improved significant in the active group ( P < .05 ) . CONCLUSION Immunotherapy can reduce the development of asthma in children with seasonal rhinoconjunctivitis Background Characterization of fatal and non‐fatal reactions to food indicates that the majority of reactions are due to the ingestion of prepared foods rather than the non‐processed allergen . In an ongoing study that used a double‐blind placebo‐controlled food challenge to investigate peanut allergy and clinical symptoms , the observed reaction severity in four of the first six subjects was greater than anticipated . We hypothesized that this was due to differences in the composition of the challenge vehicle 
    Output:
    
Initially there were anecdotal reports from communities where peanut ingestion was high .
These population s had an extremely low incidence of peanut allergy .
This has been followed by a recent formal study of Jewish children in Israel where early peanut exposure is associated with an approximate 10-fold lower incidence of peanut allergy compared with their UK Jewish counterparts .
At present it is believed that there is a bellshaped curve underpinning the relationship between allergen dose during pregnancy and early infancy , and the development of clinical sensitisation .
Thus , at very low doses of allergen the threshold for sensitisation is not achieved and the adaptive immune system remains naive to the presence of the allergen .
As the allergen dose is raised , sensitisation occurs via Th2dependent mechanisms with the consequent development of clinical manifestations .
This is supported by murine studies showing that egg immunisation during pregnancy reduces the susceptibility of offspring to egg sensitisation .
However , not all studies have supported this concept as no difference was demonstrated in the development of asthma/rhinitis or skin prick test positivity to pollen allergens , between offspring whose mothers received immunotherapy compared with sibling controls .