Some infections have a behavioral fingerprint. Bartonella’s is distinctive enough that it is worth knowing by heart.
The foot pain is the one families most often fail to mention, because nobody asked and it seems unrelated. Ask.
Bartonella is intracellular and lives in the lining of blood vessels. It replicates slowly and forms biofilm, and standard serology misses it often enough that a negative result should not close the question when the clinical picture fits.
In our own data, Bartonella was tested in fewer than half the children — and over half of those tested came back positive. It is one of the highest-yield, least-ordered tests in the whole workup.
Months, not weeks. Typical courses run six months or longer, and the most common mistake is stopping when symptoms improve — well before the organism is cleared.
Serology does not track treatment well, so you judge by symptoms. Standard practice is to continue past symptom resolution, want a sustained symptom-free stretch before tapering, and then taper rather than stop.
If a treatment reliably provokes the foot pain, you have an unusually useful marker: a shrinking reaction over time is real evidence of clearing.
Bartonella treatment produces die-off. Increasing antimicrobials in a child who is constipated and under-hydrated buys you a miserable week and a setback. Open the exit before you increase the kill.
Want this answered for your own child? A Plan B synthesis reads every lab and note you have — together — and tells you what is driving the picture, what has never been checked, and what to ask for next.
The first one is free, and you keep the list either way. Phone photos of labs are fine.
Plan B for PANS is written by a parent, not a physician. Nothing here is medical advice or a substitute for your child's clinicians — it is meant to make you the best-informed person in the room when you talk to them.