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when things get worse first

Is this die-off, or is this bad?

You increase a dose and two days later your child is raging, sleepless and refusing food. Is the treatment working, or hurting? Here is how to read it.

What a Herx looks like

A Herxheimer reaction is the body reacting to what dying organisms release. In a PANS child it usually shows up as an exaggeration of that child’s own existing symptoms — more rage, more OCD, more foot pain, more fatigue, less appetite.

  • Timing: typically within a day or two of a dose increase
  • Character: their familiar symptoms turned up, not brand-new ones
  • Course: peaks, then eases over days
  • Reproducible: happens again at the same step, less each time

What is probably not a Herx

  • New symptoms unlike anything they have had — especially rash, breathing difficulty, swelling
  • Anything with fever, or a child who seems genuinely ill rather than dysregulated
  • A reaction that keeps escalating instead of peaking and easing
  • A reaction with no dose change to explain it — that is more likely a flare or a new exposure

Anything that looks like an allergic reaction, or a child who is unwell rather than agitated, is a call to the doctor, not a dose adjustment.

What to actually do

  1. Drop back one step — not to zero. You lose the progress if you stop entirely.
  2. Hold there until calm for a full week, then step up again.
  3. Support the exit: fluids, bowels moving, epsom baths, rest.
  4. Do not push through. Pushing through a Herx in a child buys a setback, not speed.
A Herx is not failure. It is evidence the treatment is reaching something — and tolerance grows. A dose that caused a reaction six weeks ago is often fine later.

The rule that prevents most of this

One change at a time, held five to seven days. If you raise two things in the same week and your child crashes, you have lost the ability to know which one did it — and you will probably drop both, including the one that was working.

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.

Start a free synthesis
Keep reading
Open the exit before you increase the kill
Why starting antimicrobials in a constipated, under-hydrated child backfires — and the order that actually works: water, bowels, binders, then herbs.
The Bartonella signature
The behavioral fingerprint that points toward Bartonella in a PANS child, why standard testing misses it, and what treatment realistically looks like.
What a flare actually is
The signs a PANS child is flaring rather than regressing, what typically triggers one, and what to do in the first 48 hours.

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.