As I understood it the reason why some parasites can have beneficial impact on some autoimmune disorders is because they have evolved the ability to suppress the immune system, not because they overwork the immune system. But I've really only heard of this being a thing with IBS.
I was seeing the allergist for my eczema and he asked me if I experienced symptom relief when traveling abroad, which I did in Honduras. He thought I may have been exposed to a parasite there that diverted my overactive immune response. go figure.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3149054/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856386/