SKIN MANIFESTATIONS AND IMMUNOLOGICAL PARAMETERS IN CHILDHOOD FOOD ALLERGY

According to Hansen's contact rule, the digestive system should be con sidered as the main shock organ, yet in food allergy, this is not the case. Very often specific food triggers clinical manifestations not in volving the digestive system; that is, reactions are manifested either in the respiratory system, as asthma or rhinitis, or in the skin. In these cases the BALT (broncho-alveolar lymphoid tissue) and GALT (gast rointestinal lymphoid tissue) units play a basic role in the sensitiza tions. The purpose of this study was to determine the most frequent sk in manifestations of food allergy among children, and the most frequen tly involved foods. We also thought it interesting to evaluate the dia gnostic reliability of the different standard immunological parameters utilized by the study team in food allergy. All patients underwent in tracutaneous tests with 12 groups of the most frequent food allergens, as well as serum IgE, antigen-specific IgE against foods, and antigen -specific histamine release tests. Antigen-specific lgG4 determination was performed in some cases. The results obtained confirmed previous studies, the most common manifestations being: angioedema (48%), follo wed by urticaria (31%) and atopic dermatitis (21%). Regarding the freq uency of sensitization to different food allergens, in mono- or polise nsitization, fish and egg stand out in our environment. Certain food a llergens are more frequently responsible for specific skin manifestati ons. Thus, for fish sensitization the most frequent skin manifestation is atopic dermatitis (50%); for egg sensitization, angioedema is the most frequent skin manifestation (50%); and for milk, urticaria (50%). Finally, and in agreement with previous works regarding the diagnosti c reliability of in vitro techniques, we found that the histamine rele ase test offered the highest percentage of diagnostic reliability. Onl y for sensitization to milk proteins did antigen-specific IgE demonstr ate higher reliability. Once again, we stress that our main problem is the lower reliability of skin tests against food allergens than again st inhalant allergens. We emphasize the importance of food as a major factor in the etiopathogenesis of atopic dermatitis, as well as the ne ed to complement the study, when possible, by means of the in vitro te chniques described.