@umbra21 - Well, barring a situation where it's not an option, I would almost always go with the flea repellent that you squirt onto the animal that lasts for three months.
I mean, it doesn't matter if they are in the garden or the house or where ever, if the pet goes there, they will try to bite it and they will be killed. Absolutely the best way to get rid of them.
As for the bites and reactions, I would use a nappy rash cream on them. It's gentle and it'd really good at staving off an infection.
I'm not sure if taking an anti-allergy tablet might work as well. Obviously if you've got a more severe allergy, you should make sure you keep your medication on hand, because you'll never know when you might encounter a flea bite.
All it takes is one person with a dog at home who carries a flea to work in their wool sweater.