How can you get treated for Lyme disease early when it's so hard to diagnose?

Not hard to diagnose. Most patients with lyme disease display the characteristic rash and associated symptoms, which makes presumptive diagnosis easy. If one tries to diagnose it using antibody testing you might wait too long to treat effectively. If you are in an area where this is common, have symptoms compatible with lyme you should be treated presumptively. May cause your antibody reactions to remain negative.