I suspect my son has pandas. Is it harmful to give him yoghurt with streptococcus thermophilus added to it?

Probably ok... I would agree with dr. Lurie. At this time, it appears to only be related to a certain type of strep, group a beta hemolytic streptococcus (gabhs). The link with other types of strep has not yet been made, but if a concern and looking for a good probiotic for children, i would recommend lactobacillus gg as more than 400 studies to date have proven its efficacy and safety. Hope this helps!
Not advised. Strep strains in probiotics of my patients with pandas have repeatedly trigger pandas symptoms; therefore, I do not use probiotics with strep containing strains. I would also avoid it in yogurt. Due to the relapsing nature of pandas it is best to minimize any possible sensitizing trigger - pandas is an autoimmune illness, so immune sensitization is the issue.
Unsure. Pandas or pediatric autoimmune neuropsychiatric disorder associated with streptococcus is a sudden onset of obsessive/compulsive behaviors or tics with a positive throat culture for strep and/or positive blood test markers for a recent strep infection. The disorder is not well classified, but appears to respond well to antibiotics such as Augmentin (amoxicillin and clavulanate) or zithromax. Talk to your doctor.