The sensitization profiles to common allergens in the SEMAIS in Kuala Kubu Baru and urban Malays in Tanjung Malim: a comparative study

Abstract

BACKGROUND: Type I hypersensitivity is characterized by the production uf IgE antibodies against allergens. Hypersensitivity reaction comprises a group of syndromes that includes asthma, atopic dermatitis and rhinitis which tends to oxcur in a familial clustcr. OBJECnVK~: The primary objective of the research is to study the prevalence of sensitization in the Orang Asli respondents (OAR) and urban respondents (URR). The secondary objectives comprise of, to compare the prevalence of sensiti;<.ation between the OAR and URR; to analyze the rdationship between sensitization and the environmental factors of the OAR; to analyze the relil1ionship betw«n sensitization to house: dust mites, Blomia /ropicaJis or Periplaneta americana and sensitization to crustaceans amnngst the OAR; and lastly to analp.e the relationship between sensitiution and kinship (father, mother and siblings) amongst the OAR. MATERIALS AND METHODS: This i$ a descriptive and analytical cross-sectional study where two different populations wert: studied. The respondents were selected on the basis of purposive and convenience sampling. In all, 97 OAR and 71 URR were studied. The tools used were a self-reporting questionnaire and skin prick test ($pn. RESULTS AND CONCLUSIONS: The prevalence of general sensiti7.ation in We OAR was 33.0% compared to 38.0"10 in URR. There was no significant difference in we prevalence of general sensitization in the two study population viz OAR and URR (x~.457, p---Q.499). In We OAR the wee most common factors in the environments to elicit hypersensitivity symptoms were daily exposure to pets and domestic animals (100"10), living in dusty homes (87.5%) and liviog in homes infested wiW cockroaches (81.3"0). In all, 24."/. of the OAR were sensili~.ed to either Dermalophagoide.f sp, B. Impicalis or P. americana. From this subgroup, 12.5% were sensitized to onc of the crustacean allergens. This was not a significant association (1.,2..1.330, F=0.359). In the kinship analysis, 28.6% of the OAR children who were sensitized and had a positive family history of sensitization. There was no significant association between positive familial sensitization and general sensitization in all children. However, in food allergen sensitization, there was a significant assoxiation between sibling food allergen sensitization history and the index child food allergen sensitization status (Xt..9.374, FE().OII).