Laboratory parameters of the 1st order – obligatory laboratory tests.
- Small blood count
- Inflammatory parameters – CRP (C-reactive protein).
- Joint puncture/spot examination (without delay!) – if bacterial arthritis is suspected.
Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.
- Differential blood picture
- Uric acid in serum/joint punctate
- Infectious serological tests (e.g., Yersinia, Salmonella, Shigella and Campylobacter, for posturethritic arthritides Chlamydia, less frequently Gonococcus, possibly also Mycoplasma and Ureaplasma; furthermore, exclusion of infections such as measles, rubella, chickenpox; cat scratch disease; Bang’s disease (Malta fever); HIV.
- Rheumatological examinations:
- Rheumatoid factor
- Streptococcal serology, including antistreptolysin titer.
- Autoantibody diagnostics: ANA, ENA, CCP-AK (for VD on rheumatoid arthritis).
- Detection of the HLA-B27 gene [ankylosing spondylitis: positive in 90-95% of cases].
- Aspiration of synovial fluid; if necessary, detection of.
- Coagulation parameters (factor VIII, IX) – if hemophilia (hemophilia) is suspected.
- Urine status
- Kidney parameters – urea, creatinine
- Creatinine kinase – if skeletal muscle disease is suspected (e.g. polymyositis).
