[Evidence-based use of methotrexate in children with rheumatic disorders. Consensus statement of the Working Group for Children and Adolescents with Rheumatic Diseases in Germany (AGKJR) and the Working Group Pediatric Rheumatology Austria].

Juvenile idiopathic arthritis (JIA) is the most common diagnosis in children and adolescents with rheumatic disorders. In many children and adolescents, JIA is successfully treated with nonsteroidal antiinflammatory drugs (NSAR) and physiotherapy. Still, in a significant number of cases the disease is resistant to this therapy and treatment with "second line" disease modifying antirheumatic drugs (DMARDs) is required. Methotrexate (MTX) is frequently referred to as "first choice second line agent" for the treatment of JIA. However, there are considerable differences among pediatric rheumatologists on how and when to use MTX. To increase drug safety, the Working Group for Children and Adolescents with Rheumatic Diseases in Germany (AGKJR) and the Working Group Pediatric Rheumatology Austria have initiated the formulation of evidence-based recommendations. Evidence is based on consensus expert meetings, a MEDLINE search with the key words "Methotrexate" and "juvenile arthritis" limited to age 0-18 years, standard textbooks and review articles, data from the central registry of the German Research Center for Rheumatic Diseases (Deutsches Rheumaforschungszentrum Berlin), experience with MTX in adults with rheumatoid arthritis (RA) and recommendations of the German Society of Rheumatology (DGRh). Based on these data, evidence and recommendations are graded and evidence-based recommendations for the use of MTX in children and adolescents with rheumatic disease are presented.