Our pediatrician gave us a cryptic warning when she called with our son's positive Lyme test results - it "may" get worse before it gets better. No specific details of what exactly this entailed were given other than it will probably take weeks or months for the knee swelling to decrease and a second round of antibiotics may be necessary. We soon learned why the hard way, as I suspect most parents of kids with Lyme do unless they've already battled Lyme before. We had only dealt with the short courses of antibiotics for Lyme that caught in the first days after the tick bite on an adult which meant at most flu-like symptoms of short duration.
I think parents of kids with late stage Lyme (any infection more than 1 month old) must be warned that the floodgates are probably going to open and a torrent of new symptoms will flow out along with a worsening of the current ones. I also think most medical professionals have no real knowledge of this aspect of the treatment nor of co-infections. Patients and families are left on their own to discover they have not one, but multiple, hard to resolve infections.
Most people with late stage Lyme actually have developed multiple tick infections as the cesspool from the tick entered the body and over time other bacteria and protozoas, not just Lyme bacteria, have taken over. These various infections co-exist in a symbiotic way as they multiply unknown in the body over months and years before the diagnosis occurs if borellia bacteria was initially missed.
The regimen of daily antibiotics seemed to push down the load of Lyme bacteria as it is supposed to which then allowed new infections to rise up and make themselves known. This can cause a lot of herxing as the body tries to shed the the dead remnants. For more information on what to expect, be sure to check out TiredofLyme.com's The Good Days and the Bad Days article.
If you are pretty sure that your child's infection is over 1 month old, the fallout from the treatment means that you will probably have to focus on the following in the days immediately after beginning antibiotics:
Working wife and mom to two, including a teen son who was diagnosed with Lyme and other co-infections from an unseen tick bite with no bulls-eye.
Touched by Lyme-Leland
Lyme Disease Challenge Blog
Tired of Lyme
Lyme MD-Dr. Jaller
All Things Lyme-Cameron Blog
Better Health Guy
Abounding in Hope blog-Christian family of 6 w/Lyme
Lyme-Debug Your Health