When a child keeps relapsing despite good treatment, the sinuses are one of the last places anyone looks — and one of the more common places pathogens hide.
The nasal passages and sinuses sit directly against the base of the brain and drain into the same lymphatic territory. Chronic colonization there provides a continuous antigen source — meaning the immune system never gets to stand down.
It is also a place standard workups simply do not look. Nobody swabs a nose that is not obviously infected.
Nasal treatment is generally sequenced: address exposure and drainage first, then targeted antimicrobial treatment if a culture supports it, then rebuild the local ecology — with the same care about die-off as anywhere else.
Simple supportive measures matter more than they sound: saline rinses, humidification, and treating allergies that keep the tissue inflamed.
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.