It's official ... "seronegative late Lyme borreliosis" ... can exist ...
http://www.theyworkforyou.com/wrans/?id=2011-12-12a.213.3&s=%28lyme+disease%29+speaker%3A12904#g213.4
http://www.theyworkforyou.com/wrans/?id=2011-12-12a.213.3&s=%28lyme+disease%29+speaker%3A12904#g213.4