Hello Allison!
Springtails can be be a major bother when they gather in large numbers.
Regarding your comment on using pest control to manage them, if you employed the help of chemicals, it may have been in vain. Springtails have shown an incredible hardiness to most chemical concoctions seeing as they are a hexapod that have been around for an estimated 400 million years and have had a lot of time to build a tolerance to most pesticides.
Springtails thrive in well fertilized, wet/moist conditions, especially if there is fungus or mold in the area. My best guess would be the ground cover of dead leaves etc. made for perfect conditions to repopulate and inhabit as there may have been a brew of fungus growing underneath in the damp environment so when it was disturbed, they went looking for new residency.
I would suggest you invest in diatomaceous earth as well as beneficial nematodes and spread them over your lawn, as well as any spots in your house with concentrated numbers. You can find more information on both products on our website. Their numbers can be greatly effected if the area they are inhabiting is kept very dry. So, if you can shy away from watering, that could be your last method of defense.
As far as your allergies, springtails might be a pointer of something more sinister lurking in your house seeing as there is little to no concrete evidence of them causing allergic reactions. If there are any leaking pipes or otherwise damp, dark places in your house, you may want to look into an inspector to check for various molds. There are an array that can cause your symptoms such as black mold.
Here is a link to our springtail information page that will shed a bit more light on the situation, as well as offer alternatives – https://www.planetnatural.com/pest-problem-solver/houseplant-pests/springtail-control/.
Hope it helps!