Objective: To determine the consequences of disregarding first-degree relatives with psoriasis (FRP) as a classification criterion in juvenile idiopathic arthritis (JIA).
Methods: Criteria were examined in children from a prospective cohort with unclassified and psoriatic JIA.
Results: FRP was the most common reason children were unclassified (57/85, 67%); all 57 children could be classified if FRP were disregarded as an exclusion criterion. FRP was a necessary inclusion criterion to classify 11/77 (14.3%) children with psoriatic JIA.
Conclusion: Eliminating FRP as an exclusion criterion, but keeping it as an inclusion criterion in psoriatic JIA simplifies classification, though it is unclear whether the resulting classification would be better.
Keywords: CLASSIFICATION PSORIASIS; JUVENILE IDIOPATHIC ARTHRITIS; JUVENILE PSORIATIC ARTHRITIS; UNDIFFERENTIATED JUVENILE IDIOPATHIC ARTHRITIS.