Periodic fevers are defined as uniform periods of fever that recur regularly in individuals who are healthy between attacks. Parents may organize life eg holidays around expected attacks and don’t have any concerns otherwise cf child with recurrent respiratory and gastrointestinal infections after starting nursery who “always has something”.

Recurrent bacterial infections esp recurrent/chronic pneumonia or otitis media may indicate a humoral immune defect. Similarly, recurrent documented viral or fungal infections may indicate a cell mediated immune defect.