Table 1. Clinical manifestations of PFAPA syndrome

	Unite States (n = 94) [26] (%)	Europe (n = 301) [27] (%)	Japan (n = 100) [5] (%)	Korea (n = 17) [10] (%)
Essential features
Periodic fever	100	100	100	100
Aphthous stomatitis	67	57	49	18
Pharyngitis	65	90	89	100
Adenitis, cervical	77	78	50	88
Additional features
Abdominal pain ± diarrhea	45	59	31	30
Headache	65	29	10	23
Rash	15	13	-	6
Arthralgia or arthritis	-	39	-	6
Lips or tongue changes	-	-	-	12
Conjunctivitis	-	5	-	-
Chest pain or cough	20	-	-	-

PFAPA: periodic fever, aphthous stomatitis, pharyngitis, and adenitis.