Periodic Fever with Thrush, Pharyngitis and Cervical Adenitis Syndrome (PFAPA) is the most common cause of recurrent fever in children. It was first described in 1987 by Marshall, and although its exact etiology is unknown, it is believed to be a non-genetic autoinflammatory disease.
It is characterized by recurrent episodes of high fever, accompanied by oral thrush, pharyngitis and/or cervical adenitis, which recur with a fairly regular periodicity (generally every 3-6 weeks) and last 3-7 days. Between episodes, the child is completely asymptomatic and has normal growth and development.