Enthesitis-Related Arthritis in Children Save

Enthesitis-related arthritis (ERA) is an emerging subset of juvenile idiopathic arthritis (JIA) recognized for its distinctive clinical characteristics.  ILAR has defined criteria for ERA and Gmuca and colleagues have performed a cross-sectional, multicenter analysis of ERA patients seen between 1989 and 2012.

Inclusion criteria required ERA seen within 3 months of initial presentation to the rheumatology clinic.ILAR criteria required eitherA) arthritis and enthesitis; or  B) Arthritis or Enthesitis plus two or more of the following: 1) sacroiliac joint tenderness and/or inflammatory spinal pain; 2) HLA-B27 positivity; 3) arthritis in a male over 6 years of age; 4) family history in ankylosing spondylitis, ERA, sacroiliitis with IBD, reactive arthritis; or acute anterior uveitis; or 5) acute anterior uveitis

They performed a retrospective cohort study of patients taken from 5 pediatric rheumatology centers, from Philadelphia, Birmingham, Cincinnati, Dallas, and Florence Italy.

The data set included 234 ERA children with a mean age of 11.6 years, and 59% were HLA-B27-positive.

At diagnosis 69% had enthesitis and arthritis at the time of diagnosis and 78% had a pauciarticular onset. ANA positivity was seen in 23% and elevated ESR (46%) or CRP (27%) was seen in a minority of patients.

HLA-B27 positivity was associated with male sex, higher active joint count, sacroiliitis, and higher disease activity at onset.

NSAIDs were the most commonly used medication (81%), followed by DMARDs (32%), steroids (14.6%),and biologic agents (15.4%), with anti-TNF agents primarily being initiation for sacroiliitis.

The majority of children with ERA were older (> 9yrs) and had a pauciarticular onset. Interestingly only a minority of ERA patients were treated with DMARDs or biologics (TNF inhibitors).