title: Unclassified early arthritis is often spondyloarthritis.
authors.forename: Kalevi
authors.initials: K
authors.lastname: Kaarela
authors.forename: Juha K
authors.initials: JK
authors.lastname: Jantti
authors.forename: Kari
authors.initials: K
authors.lastname: Lehtinen
mesh_terms: D001168:Arthritis / Q000145:classification* / Q000175:diagnosis*; D006801:Humans; D025241:Spondylarthritis / Q000145:classification* / Q000175:diagnosis*