my 9 yo's cough won't stop

[myopathymom]

My 9yo daughter has a myopathy that mainly affects her strength and stamina.  With PT and occasional wheelchair use, she does pretty well.  She was also dx with allergies (trees, grasses, weeds, cats, and dust) and reactive airway asthma when she was 4 and hospitalized in the spring.  She has been on aggressive allergie and asthma management which has worked great for 5 years.

She started coughing Oct 4 very badly and her nebulizer (pulmocort and albuterol) didn't help for the first time.  Oral steroids made her sleepless and crazy, so we stopped after 1 day (and sleepless night).  After 8 days, she was given Biaxin (sinus infection???) and Prilosec (GERD???) and got much better, but the cough never went away.  In the midst of this, she had normal PFTs, another normal spirometry, and her chest has sounded clear to a few docs.  She had some coughing each day for weeks and some nausea each day, too.  She had fever for one morning Nov 13 when her cough wasn't bad.

It got really bad again Nov 23.  Prilosec was increased and 21 days of Biaxin was prescribed, along with 3 days of Afrin and a lot of Nasonex (in addition to her regular meds and nebulizer).  It's been a week and she is no better.

I have a lot of good pediatric docs working with us, but I'm worried we are being too cautious and we are missing something.  The only other test was a milk scan which showed reflux, but no aspiration and gastric emptying was ok.  What are we missing?  She has NEVER coughed for 9 weeks.  I don't want to put her through testing unless we need to, but is there something else that we should do at this point?

[myopathymom]

She is still coughing.  She got a slight cold Dec 11 and started coughing very badly again (meaning at least once a minute all day and some coughing at night).  This was on day 14 of 21 days of Biaxin.  On Dec 14, she had normal spirometry, a normal chest xray, and a normal clinical exam for lung sounds and no sign of post-nasal drip.  Atrivent nebs were tried in the allergist office, but didn't seem to help.  

There just doesn't seem to be any mucus in her lungs to clear.  With the most recent flare, she has coughed and produced a little mucus, but it may have been more from her nose.

The allergist, GI, and pulmo suggest that endoscopy and bronchoscopy are the next step to visualize what's going on.  I am awaiting scheduling.

The neuro who follows her myopathy suggests she is not weak enough to really suggest microaspiration.  Her PFTs show normal force for breathing in and out, so I think her cough is probably effective.  He also raises the specter of habit cough, but I don't think it's likely based on the course, especially the latest flare with night time coughing.  

I suppose pertussis can't be diagnosed by lab tests after the fact (and after 2 rounds of Biaxin).  Would pertussis have shown up on PFTs, spirometry, chest xray, or would the doctor have heard anything with the stethescope suggesting pertussis over the course of this illness?

Would mycoplasma infection have shown anything residually on chest xray 2.5 months into this cough?

I am suspecting a GI cause more and more.  She is on 20mg of Prilosec morning and night.  We are limiting soda, chocolate, greasy foods, etc.  The head of her bed is lifted.  She reports that she can often feel her pills going down and it helps to eat bread when taking pills.  Nausea is better since the Prilosec, but still occurs.  

Any ideas about what the GI and pulmo might rule out and/or find on these scopes?  They will biopsy for eosiniphillic esophagitis, I know that much.

I am not willing to treat her empirically with any more medicine, especially oral steroids to which she reacted so badly, until we know what we are treating.  For almost three months empiric treatment hasn't worked, so as much as I hate the idea of sticking a tube down her throat, I guess it's time to get to the bottom of this.

[National Jewish Health]

Your daughter's cough could be due to gastric reflux, without actual aspiration, despite the Prilosec® (omeprazole).  Assessment of this, with a pH probe, might be helpful.  The treatment with Biaxin® (clarithromycin) may be for suspected Mycoplasma infection, this suspicion reinforced by her apparently good initial response.  Eradication of this organism can take weeks to months.

Another possibility would be whooping cough.  Finally, the cough could be due to sub-optimally controlled asthma, possibly triggered and sustained by a viral respiratory infection.

Her myopathy, to the extent that it interferes with effective coughing and mucus clearance could also prolong what otherwise might have been a more limited illness, whatever the cause.  Were this the case, chest percussion and drainage would facilitate clearance.