标准化屋尘螨变应原特异性免疫治疗对儿童变应性鼻炎合并哮喘的临床疗效

目的 评估标准化屋尘螨变应原特异性免疫治疗(specific immunotherapy,SIT)对儿童变应性鼻炎合并哮喘的临床疗效.方法 选择我院42例接受标准化屋尘螨SIT的变应性鼻炎合并哮喘儿童为研究对象.所有患儿治疗前、治疗1年后均进行变应原皮肤点刺试验、测定血清屋尘螨和粉尘螨特异性IgE水平、进行肺功能测定和自觉症状评分.结果 治疗1年后屋尘螨和粉尘螨的皮肤指数和自觉症状评分均较治疗前显著降低(P＜0.01,P＜0.05),而治疗前后屋尘螨和粉尘螨特异性IgE水平、肺功能(肺活量、第1秒用力呼气量、最大呼气中段流量)均无明显变化(P＞0.05).结论 变应性鼻炎合并哮喘儿童给予SIT1年后其皮肤敏感性显著改善,临床症状明显好转,但对气道炎症的影响有待于进一步的观察.     

屋尘螨皮下特异性免疫治疗的哮喘患儿肺功能及免疫学动态变化

目的：动态观察屋尘螨变应原皮下特异性免疫治疗对哮喘患儿的肺功能和免疫学影响。方法：屋尘螨过敏的轻中度哮喘患儿32例,分成治疗组(n=15)和对照组(n=17)。治疗组吸入糖皮质激素的同时加用屋尘螨变应原皮下特异性免疫治疗,对照组仅予吸入糖皮质激素治疗。检测治疗前、治疗后3月、6月、12月、18月、24月肺通气功能,观察治疗前、治疗后12月及24月哮喘发作次数并测定血清总IgE、屋尘螨特异性IgE、屋尘螨特异性IgG4、嗜酸细胞阳离子蛋白（ECP）、IL-10、IL-4及IFN-γ的变化。结果：治疗组患儿治疗后肺通气功能各项参数稳定在正常或接近正常水平;无哮喘急性发作病例的百分率治疗后高于治疗前,随治疗时间的延长而增加（P<0.05）;治疗后屋尘螨特异性IgG4高于治疗前,随着治疗时间延长而增加（P<0.01）;治疗后血清总IgE、屋尘螨特异性IgE、ECP、IL-10、IL-4、IFN-γ水平与治疗前比较,差异无统计学意义。对照组患儿治疗前后各项指标比较,差异均无统计学意义。结论：屋尘螨过敏的轻中度哮喘患儿经屋尘螨变应原皮下特异性免疫治疗2年后,肺通气功能保持正常或接近正常,无哮喘急性发作病例增加,可能与血清屋尘螨特异性IgG4浓度增高有关。［中国当代儿科杂志,2010,12（9）：715-719］     

Skin test and RAST in children allergic to common allergens

Ninety children with bronchial asthma were evaluated for the presence of house dust, house dust mite. Aspergillus fumigatus and milk allergy in vivo by prick test (skin test) and in vitro by RAST. Of the 20 children tested for house dust allergy 12 were positive by skin test and six by RAST. Only six were positive by both methods. Of 25 children tested for house dust mite, 16 were positive by skin test, 13 by RAST and 11 by both methods. Of 35 children tested for aspergillus fumigatus, 25 were positive by skin test, 19 by RAST and 11 were positive by both methods. In the case of 10 children under three years of age with known hypersensitivity to milk, all were negative by prick test and three were moderately positive by RAST method. The correlation of skin test with RAST was 65% for house dust, 72% for house dust mite, 37% for aspergillus fumigatus and 70% for milk. Overall correlation of skin test with RAST was 56·7%.     

Exposure to indoor allergens and development of allergy

House dust contains several indoor allergens which can elicit hypersensitivity and various atopic symptoms, especially in childhood. This review article focusses on house dust mite hypersensitivity to one of the most important species, Dermatophagoides , as a model. A clear dose-response relationship has been demonstrated between house dust mite allergen exposure in mattress dust samples and sensitization, i.e. serum IgE to Dermatophagoides and positive histamine release from basophil leukocytes to one of the major allergens from Dermatophagoides pteronyssinus, Der p I. 2 μg major allergen of Dermatophagoides /g of dust and 8 μg major allergen of cat/g of dust have been suggested to be threshold concentrations above which the risk of sensitization in genetically predisposed atopic children is significantly increased. Epidemiological studies showed house dust mite allergens to be one of the most important risk factors in the development of atopic airway disease. A relation between age at onset of the first wheezing episode and house dust mite allergen exposure at the age of 1 year has been observed. There are various factors influencing house dust mite growth, and many studies have been performed to reduce house dust mite allergen exposure. Until now, none of the approaches appeared to have achieved sufficient mite and mite allergen reduction.     

Cockroach allergy in a group of Turkish children with respiratory allergies

Exposure to cockroach may lead to exacerbations of bronchial asthma and/or allergic rhinitis in sensitized patients. Although there is a widespread belief that cockroach allergy is a common problem in patients with respiratory allergies, little is known in Turkish children. In order to investigate the prevalence and characteristics of cockroach allergy in respiratory allergic children, we performed a study in newly referred children with respiratory allergies. All patients underwent questionnaire-interview and skin prick tested with common inhalant allergens in addition to two cockroach allergens: Blatella germanica (Bg) and Periplaneta americana (Pa). A subgroup of patients was also serologically investigated for specific IgE against Bg and house dust mite. Three hundred- and thirty-seven children aged 2-16 years were recruited for the study and 77.7% of these were atopic, with the most common indoor and outdoor allergens of house dust mite (47.5%) and grass pollens (45.1%), respectively. According to the prick test results, allergies to Bg and Pa were 11.9% and 7.4%, respectively, and there was a weak correlation between size of the prick test and specific IgE levels for Bg allergen. Almost 30% of the cockroach-sensitive patients were allergic to both cockroach antigens. Seventy percent of cockroach-sensitive patients were also sensitive to house dust mite, and only 1% were monosensitive. Dwellings in the Middle Anatolia and Black Sea regions were less commonly infested by cockroach compared to the dwellings in other regions. In conclusion, our preliminary study showed that cockroach sensitization is common among children with respiratory allergies irrespective of infestation history, suggesting that addition of cockroach allergen to the routine allergy screening panel is critical.     

Influence of month of birth on house dust mite allergy

We determined the birth month of a sample of 208 patients with bronchial asthma or rhinitis and positive skin test to house dust mite. The majority of patients were born in the summer and autumn months. The increased incidence of house dust mite allergy in patients born in the months of July to September, when house dust mites are most abundant, corresponds to a relative risk of 1.43. It is important that exposure to house dust mites in early childhood is kept to a minimum as exposure to allergens may influence the development of allergic disease in later life.     

Vacuum cleaning decreases the levels of mite allergens in house dust

To investigate the capacity of chemical treatment of surfaces and the difference in capacity among common vacuum cleaners to reduce mite allergen content in house dust, we recruited 52 families with allergic children. Ten families used their central vacuum cleaners. Forty-two families were randomly divided into four groups with 10 or 11 families in each. These families used cither new vacuum cleaners with either HEPA (High Efficiency Paniculate Air) or micro-filters, or their own vacuum cleaners with either tannic acid or placebo. Dust samples were collected from carpets and upholstered furniture in the living rooms and from the mattresses of the children at Days 0, 7, 21, and 35. Der p I and Der f I allergens were determined by sandwich ELJSA, After one week, tannic acid reduced the concentration of mite allergens/g of dust and the total amount/sampling area by 30% and 34%, respectively (p < 0.05), but there was no significant decrease in relation to placebo. After 5 weeks, central, HEPA- and micro-filter vacuum cleaners decreased the mite allergen concentration by 10–50% (p < 0.05) and the total amount of mite allergen from the investigated areas by 50–85% (p < 0.01). In relation to the placebo group the decrease was significant for HEPA-and micro-filter vacuums (p < 0.05), The total amount of mite allergens/ sampling area was more significantly (p < 0.05) reduced than the con-centration/g of dust. We conclude, that tannic acid reduces mite allergen concentrations in dust and total amount/sampling area for a short period of time. Central, HEPA- or micro-filter vacuum cleaners reduce mite ellergen concentrations and still more the total amount of mite allergen in house dust when used regularly for long periods. Therefore, when the total house is thoroughly cleaned, tannic acid should be applied to car pets and upholstery and low mite allergen levels maintained by using modern vacuum cleaners.     

Dust-free bedrooms in the treatment of asthmatic children with house dust or house dust mite allergy: a controlled trial

Twenty asthmatic children with prick tests positive for house dust or house dust mites were allocated to two groups that were matched for severity. One group was provided with zippered vinyl covers for pillows, mattresses, and box springs, and instructions for making the bedroom as easy to keep clean as a hospital ward; the other group was not. At the end of a 1-month study period, there was a marked and statistically significant difference in symptoms and signs of asthma between the two groups. Those with a dust-free bedroom had fewer days on which wheezing was observed, medication was given, or an abnormally low peak expiratory flow rate was recorded. Bronchial tolerance to aerosolized histamine significantly improved in the group whose bedrooms had been modified. A dust-free bedroom diminishes bronchial irritability and is a practical and effective method for decreasing asthma in children with house dust or house dust mite allergy.     

Allergic factors associated with the development of asthma and the influence of cetirizine in a double-blind, randomised, placebo-controlled trial: First results of ETA®

There is a common progression known as the allergic march from atopic dermatitis to allergic asthma. Cetirizine has several antiallergic properties that suggest a potential effect on the development of airway inflammation and asthma in infants with atopic dermatitis. Methods. Over a two year period, 817 infants aged one to two years who suffered from atopic dermatitis and with a history of atopic disease in a parent or sibling were included in the ETAC^® (Early Treatment of the Atopic Child) trial, a multi-country, double-blind, randomised, placebo-controlled trial. The infants were treated for 18 months with either cetirizine (0.25mg/ kg b.i.d.) or placebo. The number of infants who developed asthma was compared between the two groups. Clinical and biological assessments including analysis of total and specific IgE antibodies were performed. Results. In the placebo group, the relative risk (RR) for developing asthma was elevated in patients with a raised level of total IgE (≥ 30 kU/I) or specific IgE (≥ 0.35 kUA/I) for grass pollen, house dust mite or cat dander (RR between 1.4 and 1.7). Compared to placebo, cetirizine significantly reduced the incidence of asthma for patients sensitised to grass pollen (RR = 0.5) or to house dust mite (RR = 0.6). However, in the population that included all infants with normal and elevated total or specific IgE (intention-to-treat - ITT), there was no difference between the numbers of infants developing asthma while receiving cetirizine or placebo. The adverse events profile was similar in the two treatment groups. Discussion. Raised total IgE level and raised specific IgE levels to grass pollen, house dust mite or cat dander were predictive of subsequent asthma. Cetirizine halved the number of patients developing asthma in the subgroups sensitised to grass pollen or house dust mite (i.e. 20% of the study population). In view of the proven safety of the drug, we propose this treatment as a primary pharmacological intervention strategy to prevent the development of asthma in specifically sensitised infants with atopic dermatitis.     

尘螨标准化免疫治疗85例哮喘儿童疗效相关指标分析

目的 观察哮喘特异性免疫治疗(Specific immunotherapy,SIT)过程中变应原注射时间、变应原累积注射量及糖皮质激素吸入剂量、最高呼气流量、总IgE、螨特异性IgE等的变化.方法 根据纳入标准选择2005年2月-2008年6月我院哮喘免疫治疗中心就诊的过敏性哮喘患儿,进行同期对照回顾性分析,其中治疗组接受尘螨标准化变应原特异性免疫治疗,以每4次变应原注射为观察点,历时3.4年,观察治疗时间、变应原累积注射量、糖皮质激素吸入量、最高呼气流量变化、总IgE和螨特异性IgE变化,对照组仅行药物治疗,比较两组糖皮质激素吸入量及哮喘发作情况,并在SIT结束时评估疗效.结果 SIT组85例,男45例,女40例,年龄(7.6±1.4)岁,对照组病例50例,单纯药物治疗,男28例,女22例,年龄(7.7±1.5)岁.SIT第20次注射、治疗(38.7±2.4)周时,变应原累积注射量达(69.7±4.8)μg,糖皮质激素吸入量明显少于对照组(t=2.359,P＜0.05);SIT组最高呼气流量较治疗前升高,有统计学意义(F=7.874,P＜0.05);SIT前后总IgE变化无统计学意义(t=0.313,P＞0.05),螨特异性IgE变化无统计学意义(tDerp=0.517,tDerf=0.717,P＞0.05);SIT组疗程结束时患儿家长对病情主观评价:45.9%表示明显好转,36.5%表示中度好转,16.5%表示稍有好转,1.1%表示无改变;两组患儿在治疗结束时进行疗效评估,SIT组控制率达85.5%,对照组为62.0%,两组比较差异有统计学意义(x2=10.150,P＜0.01),提示SIT有效..结论 哮喘特异性免疫治疗第20次注射后,螨过敏性哮喘患儿糖皮质激素吸入剂量显著减少;85%以上患儿在SIT结束时哮喘得到控制;总IgE和螨特异性IgE变化无统计学意义.     

Hyposensitization with extracts of house dust and mites adsorbed on aluminium-hydroxyde (allpyral) in children with bronchial asthma (author's transl)]

Since the year 1971 the authors have treated 39 asthmatic patients with Allpyral house dust vaccins containing Dermatophagoides farinae extract. 16 of these children previously had similar treatment, but without mite extract, and this was changed because of the poor results. Patients allergic only to house dust and mites were selected according to the skin tests. Skin reaction to mite extract did not change even in symptomfree children in contrast to the decrease or disappearance of skin sensitivity to house dust. 23 out of 39 patients had no symptoms or only mild and short wheezing occasionaly in the last 3-6 months of treatment. There were six patients whose symptoms remained unchanged during the treatment. These children were all among the 16 asthmatics who previously had an unsuccessful house dust hyposensitization. So every patient whose treatment was started with the combined house dust-mite Allpyral has imporved, only 5 of the 23 still had yet a few asthmatic attacks.     

The effect of montelukast on allergen-induced cutaneous responses in house dust mite allergic children

The benefits of a leukotriene modifier on allergen-induced cutaneous responses have not been studied in children. We hypothesized that a leukotriene-receptor antagonist would provide protection against allergen-induced early and/or late phase cutaneous responses in susceptible children. In a randomized, double-blind, placebo-controlled, cross-over study in 6- to 15-year-old house dust mite allergic children, we compared the benefit of either montelukast or a matching placebo for 2 days on cutaneous responses induced by intradermal injection of house dust mite extract. Responses were measured as the mean of the longest diameter and its longest perpendicular of the induration response after 10, 20 min, 4 h and 6 h of the challenge. A total of 30 children were randomized to placebo or montelukast. The mean decline from baseline was significantly greater (p = 0.04) in the montelukast-treated children [−5.20 mm (−12.03–1.63)][median (95% CI)] than in the placebo-treated children [0.13 mm (−6.46–6.73] at 6th hour of the challenge, as was the mean diameter (p = 0.04), but did not differ in the remaining time points. We concluded that in house dust mite allergic children, montelukast 5 mg provided significant improvement in allergen-induced cutaneous late-phase responses, suggesting its contribution to allergic skin responses and its potential therapeutic value.     

Value of the basophil stimulation test in the diagnosis of juvenile bronchial asthma

The diagnostic value of histamine liberation from basophil granulocytes (BST) was investigated in asthmatic children with house dust, house dust mite or moulds allergy. BST corresponded at about 80% to skin prick test (PRICK) and radio-allergo-sorbens test (RAST) in 178 patients. The relevance of the results of BST, PRICK and RAST for the asthmatic symptoms was proved by bronchial provocation in 77 children. BST corresponded clearly better to the inhalation test than PRICK and RAST. Correspondence of BST in house dust mite allergy amounted to 94%, in house dust allergy to 100%, and in moulds allergy to 77%. Overall correspondence of BST was 92%. Even when RAST and PRICK showed different results correspondence of BST attained 91%. In cases with identical results of BST, PRICK and RAST the bronchial provocation test corresponded in 98%. It is concluded, that if history fits to BST, RAST and PRICK bronchial provocation is no longer essential for the diagnosis of relevant allergens in perennial childhood asthma. This seems to hold also in cases of house dust or house dust mite allergy, where the result of PRICK or RAST is different. Especially in childhood the use of BST in the diagnostic procedure provides the following advantages: risks of bronchial provocation and the necessary hospitalisation can be avoided, cooperation of the patient is not needed, and costs can be reduced.     

Mite Antigen in Kawasaki Disease

The relation between house dust mite antigen and Kawasaki disease (KD) wasexamined immunologically in 60 patients with KD.

• 1) In most patients, the serum IgE was significantly raised during the acute phase of the disease and fell gradually during convalescence. 2) Although anti-mite (Dermatophagoides pteronyssinus) specific IgE (RAST) values during the illness were significantly raised in only 15 patients (25%) when expressed as RAST scores, there was a correlation between serum IgE and anti-mite specific IgE (expressed as counts/min) (r=0.56; p<0.01). 3) An intradermal skin test on reactivity to mite antigen gave positive or false-positive in 34 of 60 patients (57%) transiently or persistently during the illness. 4) The serum levels of anti-mite (D.pteronyssinus) specific IgG were estimated by the IgG RAST method. In 15 of 20 patients (75%) RAST values were persistently or transiently high. 5) The presence of mite antigen in circulating immune complexes in the patients was examined by Raji cell assay and the direct fluorescein isothiocyanate labelled anti-mite rabbit gammaglobulin method. In three of eight patients specific fluorescence was seen on the surface of cells. 6) The proliferative responses of lymphocytes to mite ryltigen and phytohaemaglutinin (PHA) were examined in six patients. The response to mite antigen of lymphocytes from the patients was significantly higher than those of age-matched controls (p<0.0.1). 7) More mite (Dermatophagoides spp) were found in house dust collected from the homes of 12 patients than in that of dust from 10 control homes (p<0.0 1).

These results support the hypotheses that mite antigen may invade the body via the upper respiratory tract and act as a respiratory allergen and form circulating immune complexes, resulting in an immune copledx disease such as vasculitis.     

Sensitization of Children in the Stockholm Area to House Dust Mites

ABSTRACT. Atopic sensitization of children in the Stockholm area to house dust mites (HDM) was investigated in a case-control study. Sixty children with and 60 without positive skin prick tests for HDM were matched for age and sex. HDM-sensitized children had previously more often lived in other areas known to be mite infested than the control children. Sensitization to mites was related to dampness in the homes, but no significant relationship was found to the type of residence, frequent visits to a summer house in the archipelago or parental smoking. Dust samples from mattresses of the children with the strongest positive reactions to miles in skin prick tests and the respective controls were subjected to an enzyme immunoassay, to measure the content of the major allergens of the Dermatophagoides ( D. ) species D. pterinyssinus, D. farinae and D. microceras. Mattress dust samples from the beds of HDM-sensitized children contained significantly higher HDM antigen concentrations than those from the beds of controls. Private houses contained significantly more HDM antigens than flats and 10 of 11 homes in which a dampness problem was recognized contained mite antigens. It is postulated that mite infestation is increasing in the area, energy-saving measures creating improved conditions for HDM survival.     

Sensitization of children in the Stockholm area to house dust mites

Atopic sensitization of children in the Stockholm area to house dust mites (HDM) was investigated in a case-control study. Sixty children with and 60 without positive skin prick tests for HDM were matched for age and sex. HDM-sensitized children had previously more often lived in other areas known to be mite infested than the control children. Sensitization to mites was related to dampness in the homes, but no significant relationship was found to the type of residence, frequent visits to a summer house in the archipelago or parental smoking. Dust samples from mattresses of the children with the strongest positive reactions to mites in skin prick tests and the respective controls were subjected to an enzyme immunoassay, to measure the content of the major allergens of the Dermatophagoides (D.) species D. pterinyssinus, D. farinae and D. microceras. Mattress dust samples from the beds of HDM-sensitized children contained significantly higher HDM antigen concentrations than those from the beds of controls. Private houses contained significantly more HDM antigens than flats and 10 of 11 homes in which a dampness problem was recognized contained mite antigens. It is postulated that mite infestation is increasing in the area, energy-saving measures creating improved conditions for HDM survival.     

儿童血清过敏原与哮喘发生关系的探讨

目的探讨儿童血清特异性Ig E(s Ig E)过敏原与哮喘发生的关系。方法采用免疫印迹法对2004年12月至2013年4月就诊的2 239例1~14岁单纯哮喘患儿(n=1 415)和非过敏性疾病患儿(n=824)的血清s Ig E过敏原进行检测,分别建立所有样本、不同年龄及不同性别单纯哮喘与非过敏性疾病的病例对照模型,采用多因素logistic回归分析探讨过敏原与哮喘发生的关系。结果 2 239例患儿中,血清s Ig E阳性者1 028例(45.91%),过敏原阳性率居于前三位的为户尘螨(15.68%)、屋尘(14.29%)和霉菌类(13.40%)。病例对照研究结果显示,户尘螨、霉菌类、屋尘、腰果/花生/黄豆是哮喘发病的危险因素(P0.05);不同年龄组与哮喘发生相关的过敏原有所不同,1岁~组儿童仅屋尘与哮喘的发生有关,户尘螨和屋尘是3~14岁儿童哮喘发生的危险因素,而霉菌类是6~14岁儿童哮喘发生的危险因素(P0.05);户尘螨和屋尘是男、女儿童哮喘发生的危险因素(P0.05),而腰果/花生/黄豆和霉菌类仅是男性儿童哮喘发生的危险因素(P0.05)。结论户尘螨、屋尘、霉菌类为哮喘患儿最常见过敏原,且与哮喘发生关系极为密切。     

The effect of high-efficiency and standard vacuum-cleaners on mite, cat and dog allergen levels and clinical progress

The major triggers for allergic asthma are exposure to allergens of the house dust mite, Dermatophagoides pteronyssinus , and of pets. Unfortunately studies of techniques designed to reduce house dust mite and pet allergens have had mixed results. However, new so-called 'improved' products continue to appear on the market and require subjective evaluation. The homes of 60 house dust mite-allergic patients were studied to compare the effects of high-efficiency and standard vacuum-cleaners on allergen concentration. Der p 1 (house dust mite), Fel d 1 (cat) and Can f 1 (dog) allergens were measured in four separate locations in each home. Clinical analysis was by lung function, bronchodilator usage and histamine challenge techniques. There was a significant reduction in Fel d 1 (ng/m²) in dust samples from the living-room carpet (p = 0.046), bedroom carpet (p = 0.003) and mattress (p = 0.013) and living-room sofa (p = 0.005) after 12 months of using the high-efficiency cleaners, but only in the mattress sample using the standard cleaners (p = 0.014). Can f 1 (ng/g dust) was reduced in the mattress sample after using the high-efficiency vacuum-cleaners (p = 0.028), but not at other sites. Der p 1 levels were not significantly changed over this period. Clinically, patients in the high-efficiency group showed improvements in peak expiratory flow rate (PEFR) (p = 0.004), FEV₁ (p = 0.026) and bronchodilator usage (p = 0.005) after 12 months. When the cat-sensitive patients were analyzed separately, improvements in histamine PC₂₀ (p = 0.039) were also seen. Reducing Fel d 1 concentrations, in the absence of any change in Der p 1 concentrations, can produce significant improvements in the lung function of atopic, asthmatic patients. This effect was primarily achieved in those patients with cat sensitivity, but who did not possess a cat themselves.     

Prenatal exposure to mite and pet allergens and total serum IgE at birth in high-risk children

To examine the relationship between prenatal exposure to mite, cat and dog allergens and total serum IgE at birth in newborns at high risk of asthma. In the homes of 221 newborns with at least one first-degree relative with asthma, concentrations (ng/g dust) of allergens of house dust mite (mite), cat and dog were measured at the fourth to sixth month of pregnancy in dust samples from the maternal mattress and living room. At day 3-5 after birth, total IgE was measured in capillary heel blood. A total number of 174 blood samples were available (11 mothers refused newborn's blood sampling, and in 36 cases the blood sample was too small for analysis). In 24% of the newborns, total IgE was elevated (cut-off value 0.5 IU/ml). A significant dose response relationship was found between increasing mite allergen levels [divided in quartiles ng/g dust (qrt)] and the percentage of elevated IgE: first qrt (0-85 ng/g) 13%; second qrt (86-381) 19%; third qrt (382-2371) 26%; fourth qrt (> or =2372) 42%, respectively, p=0.01. This relationship remained significant after adjusting for passive smoking, maternal and paternal mite allergy, socio-demographic factors, birth characteristics and (breast) feeding practice in the first week of life. In high-risk newborns, prenatal exposure to mite allergens, but not to cat and dog allergens from dust of the living room and of the maternal mattress was associated with total serum IgE at birth.     

Bronchial asthma after early childhood wheezing: a follow-up until 4.5–6 years of age

Over a period of 12 months from 1981 to 1982, 83 patients aged less than 2 years were treated in hospital for acute bronchiolitis. The children were followed-up prospectively; 68 (83%) completed the study until 4.5–6.0 years of age. At this age, 17 (25%) of the 68 children with bronchiolitis still suffered from wheezing attacks. These 17 asthmatics suffered from both atopic dermatitis (29 versus 6%) and allergic rhinitis (29 versus 8%) more frequently than non-asthmatic children. In contrast, positive results in the skin prick tests were almost equally common (29 and 20%) in asthmatic and non-asthmatic children. In these tests, allergies to birch pollen, timothy grass pollen and house dust mite were most common; asthma was particularly associated with house dust mite allergy. The presence of atopic dermatitis, elevated immunoglobulin E values and repeated wheezing episodes between I and 2 years of age were significant risk factors for later asthma. In conclusion, the risk for later asthma is increased after early childhood bronchiolitis; the frequency of asthma was 25% in the present study. Our results confirm that atopics are at a greater risk of developing asthma later in childhood than non-atopics; the risk was significant from 1 year of age onwards.