Table 3. Comparison of PFAPA, SURF, monogenic HRF (i.e., FMF, TRAPS, CAPS, and MKD), and cyclic neutropenia [12,19,35,38]

Disease	Gene	Pathogenesis	Fever pattern	Features other than fever	Inheritance
PFAPA	- (polygenic)	-	Periodic (28 days) for 2–7 days	Aphthous stomatitis, pharyngitis, adenitis, Abdominal pain, headache, rash, arthralgia	- (some AD)
SURF	-	-	Irregular for 3–5 days	Oral ulcers, pharyngitis, adenitis, abdominal pain, arthralgia, fatigue, eye manifestations	-
Monogenic HRF
FMF	MEFV	IL-1 and inflammasomopathy	Irregular and short (< 3 days)	Arthralgia, erysipelas-like rash, chest pain, serositis, amyloidosis, early childhood-onset	AR (1/3 AD)
TRAPS	TNFRSF1A	ER stress	Irregular and prolonged (> 7 days)	Abdominal pain, chest pain, splenomegaly, serositis, periorbital edema, conjunctivitis, rash with myalgia, arthritis, infancy-onset	AD
CAPS	NLRP3	IL-1 and inflammasomopathy	Irregular and short (< 3 days)	Rash, conjunctivitis, deafness, NOMID, Muckle-Wells syndrome, neonatal-onset	AD
MKD (formerly, HIDS)	MVK	IL-1 and inflammasomopathy	Periodic (2–8 weeks) for 3–7 days	Rash, oral ulcer, pharyngitis, adenopathy, abdominal pain, serositis, infancy-onset	AR
Cyclic neutropenia	ELANE	- (ER stress)	Periodic (21 days) for 3–5 days	Stomatitis, oral ulcers, pharyngitis, malaise, abdominal pain, neutropenia (blood tests)	AD

PFAPA: periodic fever, aphthous stomatitis, pharyngitis, and adenitis; SURF: syndrome of undifferentiated recurrent fever; HRF: hereditary recurrent fever; FMF: familial Mediterranean fever; TRAPS: tumor necrosis factor receptor-associated periodic syndrome; CAPS: cryopyrin-associated periodic syndrome; MKD: mevalonate kinase deficiency; HIDS: hyperimmunoglobulin D syndrome; ER: endoplasmic reticulum; AD: autosomal dominant; AR: autosomal recessive; NOMID: neonatal onset multisystem inflammatory disease.