Q. My child has had strep. throat before, and he has tics and/or OCD. Does that mean he has PANDAS?
A. No. Many children have OCD and/or tics, and almost all school aged children get strep. throat at some point in their lives. In fact, the average grade-school student will have 2 – 3 strep. throat infections each year. PANDAS is considered when there is a very close relationship between the abrupt onset or worsening or OCD and/or tics, and a preceding strep. infection. If strep. is found in conjunction with two or three episodes of OCD/tics, then it may be that the child has PANDAS.
Q. Could an adult have PANDAS?
A.No. By definition, PANDAS is a pediatric disorder. It is possible that adolescents and adults may have immune mediated OCD, but this is not known. The research studies at the NIMH are restricted to children
Q.My child has PANDAS. Should he have his tonsils removed?A.
The NIH does not recommend tonsillectomies for children with PANDAS, as there is no evidence that they are helpful. If a tonsillectomy is recommended because of frequent episodes of tonsillitis, it would be useful to discuss the pros and cons of the procedure with your child’s doctor, because of the role that the tonsils play in fighting strep. infections.
Q. What exactly is an anti-streptococcal antibody titer?A.
The anti-streptococcal antibody titer determines whether there is immunologic evidence of a previous strep. infection. Two different strep. tests are commercially available: the antistrepolysin O (ASO) titer, which rises 3-6 weeks after a strep. infection, and the antistreptococcal DNAase B (AntiDNAse-B) titer, which rises 6-8 weeks after a strep. infection.
Q. What does an elevated anti-streptococcal antibody titer mean? Is this bad for my child?A.
An elevated anti-strep. titer (such as ASO or AntiDNAse-B) means the child has had a strep. infection sometime within the past few months, and his body created antibodies to fight the strep. bacteria. Some children create lots of antibodies and have very high titers (up to 2,000), while others have more modest elevations. The height of the titer elevation doesn’t matter. Further, elevated titers are not a bad thing. They are measuring a normal, healthy response – the production of antibodies to fight off an infection. The antibodies stay in the body for some time after the infection is gone, but the amount of time that the antibodies persist varies greatly between different individuals. Some children have "positive" antibody titers for many months after a single infection.
Q. When is a strep. titer considered to be abnormal, or “elevated”?A.
The lab at NIH considers strep. titers between 0-400 to be normal. Other labs set the upper limit at 150 or 200. Since each lab measures titers in different ways, it is important to know the range used by the laboratory where the test was done – just ask where they draw the line between negative or positive titers.
It is important to note that some grade-school aged children have chronically “elevated” titers. These may actually be in the normal range for that child, as there is a lot of individual variability in titer values. Because of this variability, doctors will often draw a titer when the child is sick, or shortly thereafter, and then draw another titer several weeks later to see if the titer is “rising” – if so, this is strong evidence that the illness was due to strep. (Of course, a less expensive way to make this determination is to take a throat culture at the time that the child is ill.)