How much does a round of antibiotics affect strep titers?

[colleenrn]

My son finished 15 days of Zithromax a week ago. We treated him even though his culture was negative b/c of behaviors I saw. Now I am KICKING myself that I did not do titers on him to prove to my slightly skeptical doctor that he definitely had strep. Is it too late to do the titers now? His behaviors have returned as well as his dark circles and slight rash on cheeks and I am considering taking him in this afternoon or at the latest Monday morning. I know you can have strep and still show low or normal titers, but if he does have strep again will the Zith he was on make it look like he does not have strep?

Thanks. I am so confused...

Colleen

[P_Mom]

Colleen,

I'd say, no... it is not too late...well, depending on when you suspect your child had strep. ASO peaks 3-6 weeks after strep...antiDNAaseB titer peaks 6-8 weeks post strep. If you think your child had strep before then.....then, yes, it could be too late.

 

The fact that your childs behaviors have returned after antibiotics have been discontinued indicates it is LIKELY (not definite) your child may still have high titers....if elevated, they have the potential, especially antiDNAaseB, to stay elevated for a VERY long time. I'd get them checked regardless....then you will at least have a reference to go by.

But as always...don't automatically rule out PANDAS if his levels are normal.

 

Zith stays in your system for atleast 5 days after last dose..so, I would say it is possible for the Zith to mask the strep and/or give false negatives on cultures and rapid tests. (not necessarily titers, IF they happen to be elevated...antibiotics do not bring titers/antibodies down...they kill the bacteria...however, being on antibiotics already when strep is contracted can result in blunting of titers...meaning, the antibiotics keep the titers from shooting up to a dangerous level by destroying the bacteria ASAP...keeping the need for the antibodies down.)

 

Take care!

 

 

Kelly

 

P.S. How excited are all you Moms who have kids avoiding artificial stuff that it is Halloween??!!

I have already confiscated my younger sons first round of stash today...he can, thankfully, have most of the chocolate stuff. We let the kids turn in the candy they can't have towards a toy or something, so...it really isn't too bad to deal with.

[peglem]

I don't know the answer to your titer question. But, before my daughter was on prophilactic antibiotics she would test positive for strep(rapid test) every time the behaviors came back, which was always 3-5 days after finishing a course of antibiotics. But, it took a little longer for it to come back after a course of zith, usually @ 5 days. My daughter's titers never tested high and though you still may get high titers on an ASO test, Sometimes PANDAS kids do not get high titers and well, if your doc is skeptical...you may end up pushing the doc in the wrong direction if you don't get the high titers.

[colleenrn]

Thank you for your replies! I think what may be happening is the same thing that occured with my two older children prior to having their tonsils and adenoids removed. When he is on antibiotics, the antibiotics kill enough of the strep to make his behavioral symptoms decrease and eventually go away, BUT as soon as he is not on antibiotics, the "left over" strep, hiding in his very large and probably cryptic tonsils, recolonize within days of stopping the antibiotics and all his behaviors return. Does that make sense to anyone or am I heading in the wrong direction? In light of my "theory", I would think his titers would be high, but I am afraid if they are "normal" it will be one more reason for my doc to say he does not have strep. He had a positive culture on July 7th., so about 4 months ago. His beginning of Oct. culture was negative, but I know he must have had strep based on how well he responded to the Zithromax.

Colleen

[Dedee]

Colleen,

 

I agree with the above post. What I would worry about with a skeptical doc is that if the titers were not high you would get the "I told you so" speech and end up with nothing. Of course we all know that PANDAS kids do not all have high titers. In our case, we didn't have titers checked until about four months after tonsils were removed (and the last strep infection). We got them at the request of Dr. Murphy prior to our visit. He had been on antibiotics for many weeks and his titers were still through the roof. I would have to look up the ASO, but I remember the AntiDNAse was almost 3,000. My pediatrician was VERY shocked. Dr. Murphy just said it was very typical in cases like this. I would really like to know what his are now since he has been on amoxicillin for well over a year. I just haven't gotten around to asking the ped for a order for them.

 

Is there anyway to find a doctor who agrees with the PANDAS issue to be of more help for you? It sounds like your son would do so much better with them. If you do go forward with titers please post and let us know what they were. Good luck!

 

Dedee

[EAMom]

The answer would vary with the individual child and the strain of strep. Some PANDAS children don't get high titers (the "normal" response). How fast titers drop is also variable.

 

The absence of specific biological markers for PANDAS complicates diagnosis. Many lay people and even physicians are under the mistaken impression that elevated Anti Streptolysin O or Anti Strep DNAse B titers are markers for PANDAS. All these antibodies indicate however is that a child has had a strep infection and mounted a normal immunological response. (from http://www.scielo.br/pdf/rbp/v26n4/en_a04v26n4.pdf )

 

So, yes, titers could offer evidence of a strep infection. If your child is one of those that doesn't have high titers (like mine was) though, don't let them use that as "proof" that your child doesn't have PANDAS.