Skin prick test reactivity to common aeroallergens in relation to total IgE, respiratory symptoms, and smoking in a general population sample of northern Italy

Abstract

Skin prick test reactivity to common aeroallergens in relation to total IgE, respiratory symptoms, and smoking in a general population sample of northern Italy.Skin prick test (SPT) reactivity to common airborne allergens and its relationships to sex, age, smoking habits, and respiratory symptoms/ diseases were evaluated in a general population sample (12 =2841, 8-75 years of age) living in the Po delta area (northern Italy). Subjects completed a standardized questionnaire and underwent prick tests ( 12 local allergens, a negative and a positive control) and determination of total serum IgE. Atopy was evaluated by measuring the maximal diameter for each allergen, after subtracting that of the negative control. Thirty-one percent of subjects showed a positive skin response at a 3-mm threshold. Pollens, Derinutophugoides pteronyssinus, and D. firrinlrcl caused the highest frequencies of reactions. Young people and those who had never smoked had higher prevalence rates of SPT reactivity. Asthma, asthma symptoms, and rhinitis were significantly associated with SPT reactivity in both sexes (cough only in females) and with the number of positive reactions. IgE values were also significantly associated with SPT reactivity. In conclusion, our findings indicate that almost one-third of the general population of an Italian rural area is skin test positive, emphasizing the importance of assessing atopy in respiratory epidemiologic surveys.A series of respiratory epidemiologic studies in general population samples was carried out over the last years to improve our knowledge of the natural history of airways obstructive disease (AOD) (1, 2). These studies aimed at evaluating the frequency of AOD in different geographic areas and the role of risk factors such as cigarette smoking, occupational exposure to bronchoirritant agents, familial predisposition t o AOD, childhood respiratory illnesses, outdoor and indoor pollution, and atopy ( 3 , 4).In particular, atopy, as assessed by skin test reactivity, is considered a risk factor for asthma and for bronchial hyperresponsiveness, which is regarded as the main functional characteristic of asthma ( 5 , 6).Beside the standard evaluations by respiratory questionnaire and lung function, additional tests to assess the immunologic status of subjects were

Allergy markers in respiratory epidemiology

“…Later, the proportion of reactors begins to increase. The maximum of the reactivity curve has been seen among the young adults in various populations [9]. However, a decrease of the reactivity, differing according to the sex in individuals >50 yrs, was seen at the age of 14 yrs in Denmark [102].…”

“…The prevalence of respiratory symptoms was higher in the urban area compared with the rural area. Conversely, no difference between the rural and urban areas was evident when comparing skin reactivity prevalence as a marker of atopy: 31% in the rural area compared to 32% in the urban area [9,28]. Table 1 shows the prevalence of skin test reactivity in different studies and populations: random samples of communities, subjects free of allergic symptoms or allergic populations.…”

“…With regard to speci®c skin responses, epidemiological studies indicate that Dermatophagoides, Parietaria, and Graminaceae are the allergens which most frequently give positive reactions in Italy [9,38].…”

“…In fact, atopy, as assessed by skin test reactivity, is considered a risk factor for asthma and for bronchial hyperresponsiveness, which is considered the main functional characteristic of asthma [9]. However, atopic predisposition, as assessed by prick test reactions, seems to be related not only to classical allergic conditions and symptoms, but also to other respiratory problems.…”

Allergic Rhinitis and its Impact on Asthma (ARIA) 2008*

“…Asymptomatic-sensitized subjects. The occurrence of positive responses to skin tests or the presence of specific IgE (1348) does not necessarily imply that the IgE-mediated allergy is related to symptoms, as skin prick tests are positive in up to 43% of symptom-free individuals depending on the allergen, the skin test method, the area and the population studied (patients or general population; [1349][1350][1351][1352][1353][1354][1355]. Using passive transfer tests, it was shown that these antibodies were functional (1349,1350).…”