Streptococcal infection in children is usually benign and self-limited. In a 
small percentage of children, prominent neurologic and/or psychiatric sequelae 
can occur. Sydenham chorea is the best defined and best recognized. PANDAS 
(pediatric autoimmune neuropsychiatric disorders associated with streptococcal 
infection) is a well-defined syndrome in which tics (motor and/or vocal) and/or 
obsessive-compulsive disorder consistently exacerbate in temporal correlation to 
a group A beta-hemolytic streptococcal infection. PANDAS constitutes a subset of 
children with tics, Tourette syndrome, and obsessive-compulsive disorder. In 
addition to strictly defined PANDAS, we and others have recognized several 
PANDAS variants, including adult-onset variant, a dystonic variant, a myoclonic 
variant, and a "chronic" PANDAS variant. The nosology and classification of 
these entities are rapidly evolving. The recognition that some pediatric 
neurobehavioral syndromes have infectious and/or immunologic triggers points to 
important new avenues of disease treatment. In this review, we summarize this 
complex and rapidly evolving area of clinical research.