Clinicians and researchers have recently encountered conflicting views and increasing publicity regarding the diagnosis and treatment of a subset of children that present with symptoms of obsessive-compulsive disorder (OCD) and/or tic disorders as an immune response to a Group A Streptococcus (GAS) infection. Known as Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus (PANDAS), symptoms include an abrupt onset following a GAS infection (e.g., strep throat or scarlet fever), a relapsing-remitting course of illness, and include new onset psychiatric symptoms (e.g., irritability, sudden mood changes, and separation anxiety) in addition to motor/vocal tics and/or obsessions/compulsions (Swedo et al., 1998). The prevalence of PANDAS is currently unknown although some estimates suggest that 11% to 33% of patients with OCD/tics report onset associated with an infection (Giuliano et al., 2002; Singer, Giuliano, Zimmerman, & Walkup, 2000). Difficulties in identification of base-rates and probabilities for encountering the disorder will persist until definitive criteria are established and the validation of PANDAS occurs. This chapter reviews the history, potential etiology, clinical features and the currently accepted treatments for PANDAS. Controversies regarding this disorder are

discussed in an effort to encourage critical thought and discussion regarding the potential of infection-triggered OCD.