This is extremely old now, so you probably won't even see this, but I would guess that your wife is allergic to chiggers. I have the exact same reaction to chigger bites. The most effective thing I have found is to get them off as soon as possible: the longer they have to feed, the worse my reaction is to them. They aren't hard to get off, just wash with soap and water or even a damp cloth. I use baby wipes since I have them around right now. Every time I step on any kind of grass when it is above freezing, I go in and wipe down as soon as possible. As far as after-bite treatment, I wouldn't get your hopes up. I am usually still itchy months later, and then the scars from the worse bites are still around months or even years later :( Just dab some antibiotic cream on it to prevent secondary infection, cry a little, and wait it out. Hope this helps someone, even if the original poster doesn't see it.
Yeahhh, i get the same thing. I get really bad reactions to bug bites aswell they swell up and dont go away for weeks. You could try a really strong repelent, or after being biten apply cream (for insect bites) and take some antihistomean. While i was on camp this lady who new about environment and stuff showed me this plants sap which can help with insect bites