Infant-onset juvenile idiopathic arthritis: a multicentre retrospective study

Area of Science:

• Pediatric Rheumatology
• Immunology
• Clinical Pediatrics

Background:

• Infant-onset juvenile idiopathic arthritis (JIA) is exceptionally rare, posing significant diagnostic challenges.
• Early diagnosis and intervention are critical for managing JIA and preventing long-term complications.

Purpose of the Study:

• To characterize JIA in infants, focusing on early symptoms, diagnostic delays, disease categories, and treatment outcomes.
• To compare the presentation and progression of infant-onset JIA with toddler-onset JIA.

Main Methods:

• Retrospective analysis of 90 infants diagnosed with JIA in Germany (2011-2020) from the National Pediatric Rheumatology Database (NPRD).
• Prospective follow-up data supplemented with a dedicated infant-onset JIA module.
• Matched comparison with JIA patients aged 1-6 years (toddler-onset JIA).

Main Results:

• Infants were more frequently diagnosed with systemic JIA compared to toddlers.
• The time from symptom onset to the first rheumatology consultation was significantly longer for infants (3.1 months) than toddlers (2.3 months).
• Despite similar initial disease activity, infants showed significantly higher disease activity at follow-up.

Conclusions:

• Late diagnosis of infant-onset JIA delays appropriate care, highlighting the need for increased awareness.
• Earlier recognition of non-infectious arthritis in infants is essential.
• Timely treatment initiation is vital to mitigate potential long-term consequences of JIA in infants.