Childhood-onset obsessive-compulsive disorder and tic disorders: case report and literature review.

A subgroup of childhood-onset obsessive-compulsive disorder (OCD) and tic disorders has been found to have a postinfectious autoimmune-mediated etiology. Clinical observations and systematic investigations have shown that a subgroup of children with OCD and/or tic disorders have the onset and subsequent exacerbations of their symptoms following infections with group A beta-hemolytic streptococci (GABHS). This subgroup has been designated by the acronym PANDAS: pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. Five clinical characteristics define the PANDAS subgroup: presence of OCD and/or tic disorder, prepubertal symptom onset, sudden onset or abrupt exacerbations, association with neurological abnormalities during exacerbations (adventitious movements or motoric hyperactivity), and the temporal association between symptom exacerbations and GABHS infections. The proposed poststreptococcal inflammatory etiology provides a unique opportunity for treatment and prevention, including immunomodulatory therapies such as plasma exchange and intravenous immunoglobulin. A placebo-controlled trial revealed that both intravenous immunoglobulin and plasma exchange were effective in reducing neuropsychiatric symptom severity (40 and 55% reductions, respectively) for a group of severely ill children in the PANDAS subgroup. Further research is required to determine why the treatments are helpful and to ascertain whether or not antibiotic prophylaxis can help prevent poststreptococcal symptom exacerbations.