The effect of a new breath actuated dry powder inhaler, the Turbuhaler*, was found to be reduced at inhalations slower than 28 I/minute. This flow rate could be generated by virtually all children aged >6 years, by 42 of 57 children <6 years (74%), and by six of 15 preschool children with acute wheeze (40%).Many children with asthma cannot use a pressurised aerosol correctly and therefore gain little benefit from inhalation treatment with this device. In such cases dry powder inhalers may be a valuable treatment alternative. However, powder inhalers require a certain minimum inspiratory flow rate from the patient to work effectively.' 2 This limits the use of powder inhalers in children, whose inspiratory flow rate varies, both with age and expiratory pulmonary function.Dry powder inhalers are designed in different ways and vary substantially in resistance to air flow. It is important, therefore, for physicians prescribing inhalation treatment for children to know in detail the peak inspiratory flow rate (PIFR) that various age groups can generate through an inhaler as well as the lowest inspiratory flow rate at which the inhaler will work effectively.We conducted the present studies to answer these questions with regard to a new multidose powder inhaler, terbutaline Turbuhaler (Astra), which delivers pure freeze dried drug without any carrier substance or additives.

In a multicenter study conducted at four Danish hospital pediatric departments, the parents of 472 consecutive children were informed of this project to determine the incidence of intolerance of food additives among children referred to an allergy clinic with symptoms of asthma, atopic dermatitis, rhinitis, or urticaria. After a 2-week period on an additive-free diet, the children were challenged with the eliminated additives. The food additives investigated were coloring agents, preservatives, citric acid, and flavoring agents. Carbonated "lemonade" containing the dissolved additives was used for the open challenge. Two doses were used: a low dose and a 10-fold higher dose. Gelatin capsules were used for a double-blind challenge. The children were 4-15 years old, and they were attending an outpatient pediatric clinic for the first time. Of the 379 patients who entered the study, 44 were excluded and 335 were subjected to open challenge. A total of 23 children developed positive reactions after the open challenge. Sixteen of these patients accepted the double-blind challenge, and six showed a positive reaction to preservatives (atopic dermatitis, asthma, rhinitis), coloring agents (atopic dermatitis, asthma, urticaria, gastrointestinal symptoms), and citric acid (atopic dermatitis, gastrointestinal symptoms). The incidence of intolerance of food additives was 2% (6/335), as based on the double-blind challenge, and 7% (23/335), as based on the open challenge with lemonade. Children with atopic skin symptoms had a statistically increased risk of a positive reaction. This may have consequences for the future clinical investigation of children with atopic cutaneous symptoms.

The prevalence of intolerance to food additives was assessed in a group of unselected school children aged 5-16 years. A study group of 271 children was selected on the basis of the results of a questionnaire on atopic disease answered by 4,274 (86%) school children in the municipality of Viborg, Denmark. The children in the study group followed an elimination diet for two weeks before they were challenged with a mixture of food preservatives, colourings and flavours. The challenge was open and the additives were prepared as a fizzy lemonade. If the open challenge was positive, a double-blind placebo controlled challenge with gelatine capsules was performed. The study included 281 children, 10 were excluded, and the remaining 271 children were given the open challenge (98 healthy controls and 173 with atopic symptoms). The open challenge was negative in all 98 healthy control children who had not reported any atopic symptoms. Of the 173 children reporting present or previous atopic disease 17 had a positive open challenge. Of these 17 children 1 experienced gastrointestinal symptoms, 13 reacted with aggravation of atopic eczema, and 3 with urticaria. Twelve of these 17 children went through the double-blind challenge which was positive in 6 cases. Five of these 6 children had positive reactions to synthetic colourings and 1 to citric acid. No serious reactions were seen. Based upon calculations of the results from this study and an earlier multi-center study in children referred to hospital clinics, the prevalence of intolerance to food additives in school children is estimated to be 1-2%.

No abstract

As a result of a 1990 survey by questionnaire, the symptoms of atopy among all 4,952 school children aged 5 to 16 years in the municipal district of Viborg, Denmark, were registered. Random checks, made among children who were recorded as having symptoms, and others who were recorded as having none, accorded well with the information supplied by the parents about symptoms and the clinical diagnosis of a specialist; 10.5% of all school children had rhinitis, 7% had atopic eczema, 3.2% had urticaria and 4.5% had asthma; 1/4 of all those questioned had shown symptoms within the last year, and a further 13% of all the children were reported as having had atopic symptoms that had disappeared more than a year previously. Of the children showing symptoms within the last year before the survey, 2/3 had gone to a doctor. Of the children with present symptoms, largely asthma, 1/4 had been referred to a hospital allergy clinic. For 1/3 of the children with present symptoms, these had led to no contact with a doctor. Of the cases with present symptoms, 6.5% had had contact with natural healers or chiropractors. Rhinitis and asthma were most frequent among boys, while atopic eczema was most frequent among girls. For both sexes, the frequency of rhinitis increased during their years at school, while the frequency of skin symptoms fell.