This study confirms that allergy to egg is frequent in a child population.

A substantial number of parents perceive that their children have adverse reactions to food, but it is well documented that objective assessments agree with only one-quarter to one-half of parentally reported reactions. In order to prevent wrong diagnoses and curtail unnecessary or inadequate diets, primary health care providers need to deal with the parental perception of adverse reactions to food. A description of the prevalence and pattern of parentally perceived adverse reactions to food in children is needed to meet this challenge. The aim of the present study was to estimate the prevalence, incidence and cumulative incidences of parentally perceived adverse reactions to food in children younger than 2 years of age, and to study the duration of the reactions. A population-based cohort of 3623 children born in Norway was followed from birth until the age of two. At 6-month intervals, the parents completed questionnaires regarding the occurrence and type of any reaction to food. Information was available on the outcome measure at all age points for 77.4% of the families and these were used in the analyses; 3.8% of the cohort were entirely lost to follow-up. The cumulative incidence of adverse reactions to food was 35% by age two. Fruits, milk and vegetables accounted for nearly two-thirds of all reported reactions. Milk was the single food item most commonly incriminated, the cumulative incidence being 11.6%. The cumulative incidences of reported reactions to fruits and vegetables were 20.4% and 7.3%, respectively, with citrus fruits, strawberry and tomatoes as the most common food items in these groups. The cumulative incidences were less for food reactions associated with eggs (4.4%), fish (3%), nuts (2.1%) and cereals (1.4%). The duration of the reactions was short - approximately two-thirds of the reactions were not reported again 6 months later. However, the probability of remission depended on the food item concerned, the age at onset of reactions, and whether the reaction had been reported previously or not. Adverse reactions to food are reported by the parents of one-third of children in Norway before the age of two. The most striking feature of this study is the short duration of the food reactions, as approximately two-thirds of the reactions are not reported again 6 months later. Nevertheless, the high frequency of reactions attributable to milk is of concern. Milk is an important part of the Norwegian diet for children, and if removed from the diet its nutritional value is not easily replaced. Further studies are needed to assess the degree to which parents alter the diet of their children based upon perceived reactions to food.

SummaryA method for biological equilibration (BE) of allergen reference preparations using the skin‐prick test (SPT) method and histamine HCl 10 mg/ml as reference substance (reference method), was evaluated. The precision was low for weals less than 10 mm2. The slope (log weal area/log concentration) of allergen and histamine did not vary significantly between investigators and allergens. The median slopes were 0.39 (n= 384) and 0.34 (n= 397), for allergen and histamine, respectively (P < 0.01). The concentration of allergen eliciting a weal of the same size as that of histamine HCl 1 mg/ml (Chl) in the median sensitive patient, 1000 Biological Units/ml (BU/ml), did not vary significantly between clinics/geographical regions (grasses, mites and moulds). As BE is repeatable between regions. BUs estimated by this method are generally valid. A high correlation (r= 0.91, P < 0.001) was found between the median Chl as estimated with histamine 1 and 10 mg/ml as reference substance, respectively. Thus, this reference method for BE is valid. The precision of the SPT method with histamine HCl 1 mg/ml is not as good as with 10 mg/ml, which is therefore recommended as the reference concentration.

The present study confirms previous findings that parents overestimate milk as a cause of symptoms in their children; however, it also indicates that unrecognized reactions may be a problem as well.

Aim: To study the age when symptoms of adverse reactions to milk occur, in premature and term children, the debut of various symptoms, immunoglobulin E (IgE)-and non-IgE-mediated reactions and the frequency of tolerance at 1 year.Methods: Six hundred and eight children, 193 premature and 416 term infants, were followed. Symptomatic children were invited to a clinical examination. The criteria for the diagnosis were:histories of suspected cow's milk allergy (CMA) and proven IgE-mediated reactions to cow's milk or positive elimination/challenge tests.Results: Twenty-seven out of 555 (4.9%) were diagnosed with adverse reactions to cow's milk. All had symptoms before 6 months of age. The main symptoms were: pain behaviour (13), gastrointestinal symptoms (7), respiratory symptoms, (6) and atopic dermatitis (1). One child had proven IgE to cow's milk. Premature and term infants displayed the same symptoms and age of debut. Thirteen children were tolerant to cow's milk at 1 year.Conclusion: Adverse reactions to milk start early in life, with pain behaviour, gastrointestinal, and respiratory symptoms being the most common, and rarely atopic dermatitis. Non-IgE-mediated reactions were the most frequent. Symptoms and age of debut were the same in premature and term infants. Half of the children tolerated cow's milk at age 1.