THE IMPACT OF PARASITIC INFESTATIONS ON THE DEVELOPMENT OF ALLERGIC DISEASES AND CHANGES IN IMMUNE REACTIVITY IN CHILDREN

Parasitic infestations remain an important pediatric problem because they may influence not only nutritional status and gastrointestinal function but also the maturation and regulation of the immune system. Helminths and several protozoal parasites can stimulate type 2 immune responses characterized by activation of T-helper 2 cells, increased production of interleukins 4, 5 and 13, eosinophilia, mast-cell activation and elevated immunoglobulin E. These mechanisms overlap substantially with the pathways involved in bronchial asthma, allergic rhinitis, atopic dermatitis and urticaria. At the same time, chronic helminth infection may activate regulatory T cells and anti-inflammatory mediators such as IL-10 and TGF-beta, which can suppress or modify allergic inflammation. This thesis summarizes the main mechanisms through which parasitic invasion can alter immune reactivity in children, reviews the clinical associations with allergic disease, and emphasizes the importance of integrated parasitological and allergological assessment in pediatric practice.