Role of Inhalant and Food Allergens in Child Sensitization: A Prospective Study in 176 Children

Background: The origin of atopic disease is poly factorial and the de velop ment of atopic manifestations appears to be linked to interactions be tween genetic and environmental factors.Such data seem to focus attention on the ris ing prevalence rates of atopic dermatitis, a common debilitating skin con dition in infants and young children.They also often have asthma and/or al lergic rhinitis. Patients and Methods:The aim of the present study was to evaluate the rate of SPT (skin prick tests) and RAST response to Der p in ato p ic children with AD.We have prospectively studied 176 children (93 mal es and 83 fe ma les) aged from 6 months to 7 years, and divided into four differ ent groups, including controls.We studied also their family history in the ac companying parents Results.The data of the present study show that a signific antly higher prop ortion of children with AD have positive SPTs to Der p than the controls, while RAST was positive in a lower proportion of babies.A significant part of the parents had a positive atopic history. Con clu sion:The early on set of such disorders in different parts of the world, and the strict connec tion between cutaneous and respiratory atopy appear of primary importance.Consequent ly, there is the clinical imperative that ef fec tive strate gies should be adopted to amplify and improve preven tati ve mea sures in at highrisk (HR) babies.neously with 0.2 ml of serum from a ragweed allergic patient and 0.2 ml of serum from a non-atopic control.Twenty-four hours later ragweed pollen was sprayed into both nostrils of the tested subjects.Interestingly, within 14-31 minutes (mean: 20 minutes), all study subjects devel oped a wheal-and-flare response appeared at the injection site but not the control site., thereby demonstrating that aller gens, even if inhaled, reach the skin rapidly and then bind to IgE antibodies, thus trigger ing reactions of local anaphylaxis.In the early 1950's, Tuft et al. [11,12], carried out an interesting set of exper i ments attempting to establish the pathogenic role of inhaled pollens in AD.The authors postulated that inhalation of pollen led to perspiration, which was linked to the development of itching and subsequent eczematous lesions.Subjects were dusted with a corn starch-iodine powder prior to inhaling a very small dose of dry ragweed pollen.After several minutes, a bluish colour change (showing that sweating had occurred) was noted about the neck and in the antecubital and popliteal fosse.The eczematous changes which devel oped persisted for several days [11].Subsequent ly, Nilzen [13], reported the onset of eczematous changes in 4 out of 8 AD patients following inhalation of an Alternaria spray.Hopkins et al. [14], observed a patient in whom the inha lation of a spray containing Alternaria spores was able to induce asthma and flares of eczema.Utilizing studies, similar to those previously described by Cohen et al. for ragweed [10], Tuft et al. performed inhalation studies with Alternaria.Similarly to previous studies utilizing ragweed pollen, sweat ing and pruritus developed within minutes, and over 12-24 hours eczema tous lesions developed in sensitized sites, which persisted for 4-5 days [15].