Table 2. Diagnostic criteria for PFAPA syndrome

Thomas criteria (1999) [26]	PRINTO criteria (2019) [30]
All of 5 criteria	At least 7 of 8 criteria
1. Periodic Fever in children < 5 years of age with history of ≥ 5 fever episodes1)	1. Presence of periodicity
	2. Presence of fever for 3–6 days
2. At least 1 of 3 essential symptoms in absence of URIs or UTIs1)
i) Aphthous stomatitis
ii) Pharyngitis	3. Presence of pharyngitis
iii) Adenitis, cervical	4. Presence of cervical (lymph-)adenitis
3. Exclusion of cyclic neutropenia and monogenic HRF1)	5. Absence of diarrhea
4. Asymptomatic interval between fever episodes	6. Absence of arthritis
5. Normal growth and development	7. Absence of skin rash
Therapeutic diagnosis through tonsillectomy1,2)	8. Absence of chest pain

The criteria were supplemented by Lantto et al. (2016) [15].
Patients who do not meet 5 criteria but have complete resolution of periodic fever after tonsillectomy should be diagnosed with PFAPA.
PFAPA: periodic fever, aphthous stomatitis, pharyngitis, and adenitis; PRINTO: Paediatric Rheumatology International Trials Organisation; URIs: upper respiratory tract infections; UTIs: urinary tract infections; HRF: hereditary recurrent fever.