Juvenile Idiopathic Arthritis

Letter to the editor Hip Pain in Children Dr. med. Ayla Yagdiran, PD Dr. med. Kourosh Zarghooni, PD Dr. med. Jörg Oliver Semler, Prof. Dr. med. Peer Eysel in Heft 5/2020

The consensus based term for a rheumatic joint disorder in childhood is “juvenile idiopathic arthritis (JIA)”, and not “juvenile rheumatic coxitis.” [note: the author points out a mistake in the German-language version of the article]. It is classified according to ILAR criteria (1). Crucial to our understanding is the definition of JIA, for which the following criteria have to be met:

• Objective confirmation of arthritis/enthesitis
• <16^th year of life
• Duration longer than 6 weeks
• Other causes have been ruled out.

Rheumatoid arthritis in adults has to be differentiated from JIA. Differentiating between peri/post-infectious arthritis, which is very common in children and is often harmless, and rare, reactive arthritis requiring treatment is crucial. Both types have an infectious cause in the widest sense. To say that an infectious cause is a compulsory reason for diagnostic arthrocentesis to be carried out seems misleading. Septic arthritis is an orthopedic emergency and should be referred for arthrocentesis and joint irrigation. Peri/post-infectious arthritis does not constitute an indication for diagnostic arthrocentesis (2). Reactive arthritis often develops within a few weeks after a bout of gastroenteritis has been overcome. It is one of the spondyloarthropathies and should be treated according to the therapeutic principles of JIA. The mentioned laboratory tests to rule out infectious pathogens, including Borrelia and viruses, should be based on a well founded clinical suspicion. Measuring HLA B27 (“human leukocyte antigen”), rheumatoid factors, antinuclear antibodies (ANA) do not enable a diagnosis but merely help in classifying JIA.

The article (3) did not include details on the effectiveness and safety of intra-articular therapy using triamcinolone-hexa-acetonide. It is also important that JIA is often easily treated and has a good prognosis. Furthermore, the article (3) did not make any mention of interdisciplinary care of children with joint pain, which might help avoid unnecessary diagnostic evaluation and therapy. Much of all this is detailed in the recently revised published German consensus-based (S2k) guideline for the treatment of JIA (4).

DOI: 10.3238/arztebl.2020.0599b

Dr. med. Gregor Dückers

Zentrum für Kinder- und Jugendmedizin

HELIOS Klinik Krefeld

Conflict of interest statement

The author declares that no conflict of interest exists.

References

1. Petty RE, Southwood TR, Manners P, et al.: International league of associations for rheumatology classification of juvenile idiopathic arthritis: second revision, Edmonton, 2001. J Rheumatol 2004; 31: 390–2.

2. Mayatepek E (ed.): Pädiatrie. Grundlagen, Klinik und Praxis. Stuttgart: Urban & Fischer/Elsevier 2019; p. 389.

3. Yagdiran A, Zarghooni K, Semler JO, Eysel P: Hip pain in children. Dtsch Arztebl Int 2020; 117: 72–82

4. Gesellschaft für Kinder- und Jugendrheumatologie (GKJR) und Deutsche Gesellschaft für Kinder- und Jugendmedizin e.V. (DGKJ) (eds.): Leitlinie: Therapie der juvenilen idiopathischen Arthritis. https://www.awmf.org/leitlinien/detail/ll/027-020.html (last accessed on 15 May 2020).