Parasites and Allergy

Book excerpt: The inverse correlation between allergic diseases and helminth infections has been debated for over 30 years. It was initially assumed that the underlying mechanism is an imbalance between Th1 and Th2 responses that, as a result of reduced exposure to Th1-inducing infectious pathogens, has tipped to allergic Th2 responses. It has only recently been clearly demonstrated that helminth infections have negative effects on allergic disease manifestation. This was shown to be consistent with the activity of regulatory cell populations, which control the effector mechanisms of both Th1 and Th2. In th.