PANDAS (Paediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infection)

This is a rare condition in which a young child (typically aged 6 or 7) develops a neuropsychiatric disorder (usually obsessive-compulsive disorder (OCD) or tics) following a Group A beta haemolytic streptococcal infection (GABHS). Although the acronym PANDAS was first cited in 1998,¹ the neurological sequelae of Streptococcal infection have been well recognised (e.g. Sydenham's chorea described by William Osler in 1894).²

This is usually dramatic, with the sudden development of psychiatric/behavioural problems such as emotional lability, anxiety, night-time fears, hyperactivity and oppositional behaviour with some cognitive deficits. There may be dyskinesias e.g. mild facial or vocal tics; although if overtly choreiform movements develop the child should be considered to have developed Sydenham's chorea and these children require antibiotic prophylaxis against subsequent GABHS infection.¹

The condition generally follows a relapsing and remitting course - with exacerbations commonly triggered by infections, both bacterial and viral.

This is mainly supportive, although the case has been made for looking for and treating active streptococcal infection (i.e. throat swabs and culture if children develop sore throat with pyrexia),¹ and some advocate tonsillectomy.³
OCD is treated in similar ways whatever the cause, e.g. with behavioural therapy.