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Background: A 3-year course of specific immunotherapy (SIT) in children with hay fever to grass and/or birch pollen significantly reduced the risk of developing asthma. To investigate the long-term preventive effect, we performed a follow up – 2 years after termination of immunotherapy. Methods: A total of 183 children, aged 6–14 years with grass and/or birch pollen allergy could be investigated 2 years after discontinuation of SIT or no treatment. Conjunctival provocation tests (CPTs) and methacholine bronchial provocation tests were carried out during the season and winter after 5 years. The development of asthma was assessed by clinical evaluation. Results: The significant improvement in hay fever and CPT results observed after 3 years of SIT persisted at the 5-year follow-up. No difference in bronchial responsiveness to methacholine was found after 5 years because of spontaneous improvement during the follow-up period in the control patients. The immunotherapy-treated children had significantly less asthma after 5 years as evaluated by clinical symptoms [odds ratio 2.68 (1.3–5.7)] in favor of SIT for prevention of development of asthma and significantly less patients reported an increase in asthma scores ( P < 0.01). Conclusion: Immunotherapy for 3 years with standardized allergen extracts of grass and/or birch shows long-term clinical effect and preventive effect on development of asthma in children with seasonal rhinoconjunctivitis. [ABSTRACT FROM AUTHOR]

In search of potential new indoor allergen sources, all mites in dust from homes of 55 asthmatic children living in three climatic regions in Sweden were counted and identified by light microscope. Antibodies of the IgE class against three house‐dust mites and three storage mites were measured in corresponding serum samples. Mites were found in all but two homes from the northernmost area, where levels also were lower than in the other regions. The highest mite densities were most often found in bedrooms (50%) and living rooms (40%). Mite density was increased in homes with high humidity and was higher in bungalows than in flats. House‐dust mites predominated in the south and storage mites in the east central area, particularly in kitchens and bathrooms. Mite‐density and IgE‐antibody levels against house‐dust mites were significantly associated. The same association applied to storage mites. Other species numbered around 100 mites/g dust in some homes. Microscopy helps to identify potentially important mites. Analysing home dust only for house‐dust mites will underestimate mite exposure. Storage mites may be as relevant to sensitivity as house‐dust mites. As other species occasionally were found in high numbers, their relevance should also be assessed. [ABSTRACT FROM AUTHOR]

Oral immunotherapy (IT) was evaluated in a pilot study in two centres in children aged 8-15 years with allergic rhinoconjunctivitis. High doses (up to 20 × 106 BU monthly) of a defined freeze-dried birch pollen extract administered in enteric-coated gelatine capsules were given either daily for seven consecutive days every month or once weekly. Symptom scores, as assessed by sneezing, dripping and blockage of the nose, and redness, itching and swelling of the eyes, were significantly lower in treated patients compared to untreated, or placebo treated controls after 3 to 5 months of therapy. In all the 16 treated, but only in three of eight untreated patients, the scores were lower during the pollen season 1982 than during the pollen season preceding the treatment period, despite comparable pollen counts during the two seasons. One year after beginning treatment the reactivity in conjunctiva! provocation tests was decreased about 10-fold (P < 0.001) in the patients receiving more than 2 × 105 BU monthly compared to about two-fold in patients receiving lower doses, or placebo. Increased levels of IgE antibodies directed against birch pollen were recorded in the serum and saliva of most patients after 3-4 months of active IT. In contrast, IgG antibody responses were poor in most of the patients. Side effects, particularly from the gastrointestinal tract, appeared in all treated children. In one of them a systemic reaction occurred during IT. The study indicates that properly performed oral IT with a potent birch allergen extract in enteric-coated capsules may be effective. [ABSTRACT FROM AUTHOR]

Twenty-four children with rhinoconjunctivitis due to birch pollinosis were treated in a double-blind manner with enteric-coated capsules containing either a high dose of a birch pollen preparation (n = 11) or placebo (n = 13). The permeability of the small intestine was analysed at three different occasions with a mixture of differently sized polyethyleneglycols (PEG 400 and PEG 1000), before the start of oral immunotherapy (OIT), at the moment of maximum allergen dose, and after 3 months of therapy which was at the beginning of the pollen season. The actively treated children did not significantly change their permeability characteristics as determined from PEG recovery in the urine. By contrast, in the control group of patients the recovery of larger PEG molecules was decreased after 3 months of therapy, possibly due to the commencing pollen season. In addition, small bowel biopsies were taken at the time of maximum allergen dose from two children openly treated with OIT. Both specimens were normal. [ABSTRACT FROM AUTHOR]

Thirty children with rhinoconjunctivitis due to birch pollinosis were treated in a double blind manner for 10 months with enteric-coated capsules containing either a bitch pollen preparation (n = 14) with doses up to 1.4 × 106 biologic units per day or placebo (n = 16). Compared with the placebo group the actively treated children had less symptoms during the birch pollen season alter 3 months of therapy (P = 0.035). Skin prick reactions decreased significantly more in the active group than in the placebo group after 10 months (P = 0.01). Conjunctival sensitivity was lower in the active group than in the placebo group alter 3 months of treatment (P = 0.01) but not after 10 months. Compared with the placebo group the treated children more often increased their levels of IgG (P = 0.007) and pre-seasonal IgE (P = 0.001) against birch. There was a seasonal increase of IgE antibody level against birch in the placebo but not in the treatment group (P < 0.001). None of the treated children developed asthma, compared with five of the untreated children. No general reactions occurred and few side effects were seen during the treatment period. We conclude that in children with birch pollinosis oral immunotherapy with high doses of a biologically potent preparation in enteric-coated capsules is effective, easy to perform, economic and safe. [ABSTRACT FROM AUTHOR]

We investigated the levels of mite (Der p I and Der f I) allergen in dust from bedrooms, living rooms, kitchens, and bathrooms from 130 homes of asthmatic children in three climatic zones of Sweden. Bedroom dust samples included the child's mattress, carpets, floors, and other plain surfaces. Living-room dust samples were taken from sofas and Other furniture, carpets, floors, and other plain surfaces. The allergen levels were related to home characteristics, including absolute indoor humidity (AIH), relative humidity (RH), and air changes per hour (ach). Mite allergen was detected in 62% of the homes. Levels of Der p I varied between <16 ng and 50 μg/g dust, and Der f I between.. <16 ng and 73 μg/g dust. Because we have designed a composite type of dust collection in our study, the allergen levels found tend to average down the results. Mite allergen levels were higher in homes with dampness problems, in homes with a smoker, and in homes without a basement Homes with high absolute humidity (≥ 7 g/kg) or relative humidity (> 45%) and poor ventilation (<0.5 ach) contained higher levels of mite allergens than homes, with lower humidity and better ventilation, However, the number of ach measurements in homes was not high, and few homes had > 0.5 ach. Sensitization to house-dust mites was more common in southern than in northern and central Sweden. "High levels of house-dust mite allergen in a temperate. climate where mites are not ubiquitous are thus associated with dampness problems in homes and with tobacco smoking. Our data confirm and extend previous findings that high AIH and RH and poor ventilation increase the risk of mite infestation in homes. It seems to be important and necessary to control indoor humidity and ventilation levels, to avoid high mite allergen exposure in a temnperate climate, because 34% of mite-sensitized asthmatic children were exposed to levels of mite allergen <2 μg/g dust in their homes. The study also shows that mite allergen levels below the suggested threshold level (2 μg/g dust) are associated with mite sensitivity in children with perennial symptoms of asthma. [ABSTRACT FROM AUTHOR]

The new antiallergic drug oxatomide was evaluated in 40 schoolchildren suffering from severe allergic seasonal rhinoconjunctivitis. Antihistamine drugs had earlier given insufficient symptomatic relief. Double-blind technique was used. There was no significant difference in effect between oxatomide, the antihistamine cinnarizine in combination with phenylpropanolamine and placebo. The results do not support the hypothesis that oxatomide is superior to antihistamine drugs in the treatment of severe seasonal rhinoconjunctivitis.

In a study of immunotherapy 41 children with seasonal rhinoconjunctivitis due to deciduous tree pollen allergy were monitored by means of symptom scoring, patient self-evaluation, conjunctival provocation tests and lymphocyte proliferation in vitro to the allergen. The lymphocyte responsiveness to birch pollen decreased significantly during the first year of immunotherapy. However, neither the lymphocyte responsiveness before treatment nor changes in lymphocyte reactivity during the immunotherapy correlated with the clinical efficacy of the therapy as evaluated by changes in symptom scores, self-evaluation or conjunctival provocation test changes in the individual patients. The results indicate that lymphocyte responsiveness to an allergen cannot be used to select patients for immunotherapy, i.e. to predict whether a patient would benefit from immunotherapy or not, or to evaluate the effects of immunotherapy after beginning the treatment. However, lymphocyte proliferation response to an allergen indicates clinical sensitivity.

Repeated conjunctival provocation tests (CPT) were done in 20 children with rhino-conjunctivitis due to birch pollen allergy. Compared with the first open challenge, three successive blinded CPTs were reproducible within an allergen strength difference of one 10-potency in 92% of the tests. Based on the data, a power function was constructed, making it possible to determine the number of patients needed to discriminate CPT sensitivity of a given magnitude between two populations. During the study period specific serum-IgE increased in only three of 19 patients, indicating that stimulation of IgE antibody production is not a common consequence of repeated tests. We conclude that CPT is useful in clinical research. When indicated in clinical routine, CPT is a safe and easy test with good precision.