Laboratory diagnostics depends on the extent and localization of pain or the underlying disease.
2nd order laboratory parameters – depending on the results of the history, physical examination – for differential diagnostic clarification.
- Small blood count
- Differential blood count
- CRP (C-reactive protein)
- Borrelia antibodies (IgG, cerebrospinal fluid/serum)
- Yersinia antibodies (IgA, IgG, IgM)
- Calcium (e.g., due tohypercalcemia (calcium excess)).
- Auto-Ak (IgG) against cell nuclear antigens (synonyms: ANA, ANF, antinuclear factors).
- Auto-Ak against smooth muscle ( synonyms: SMA, ASMA, actin).
- Creatinine kinase (CK)
- CCP-Ak (cyclic citrullinated peptide).
- Rheumatoid factor (RF)
- Skin biopsy (tissue sampling from the skin) – for diagnosis of neuropathic pain and small-fiber neuropathies (special form of sensitive polyneuropathies in which mainly the thin “C-fibers” not surrounded by “medullary sheaths” are affected), if conventional electrophysiological methods do not show abnormalities and/or small-fiber neuropathy is suspected.
