Psychosis exacerbation following group A Streptococcal pharyngitis: An immune-mediated phenomenon? A case report

According to some theories that postulate an immune involvement in the pathogenesis of Schizophrenia (SCZ), autoimmunity and infections are risk factors for SCZ. We report the case of a 20-year-old female patient who received a diagnosis of SCZ at the age of 15, in concomitance with having contracted a streptococcal pharyngitis. Interestingly, since then, the patient repeated a number of Group A streptococcal (GAS) infections that, in each case, preceded recurrent significant psychotic exacerbation. GAS infections are a well-known cause of post-infectious immune-mediated conditions such as Syndeham's corea and PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections), in which a prominent SCZ-like symptomatology has been occasionally reported. The neurobiological basis of the emergence of psychotic symptoms in these cases remains largely elusive. We speculate in this article that psychotic exacerbations following GAS infections are linked to the pathophysiology of the streptococcal pharyngitis.