1. Wolfe F, Smythe HA, Yunus MB, et al. The American College of Rheumatology 1990 criteria for the classification of fibromyalgia. Report of the Multicenter Criteria Committee. Arthritis Rheum 1990;33:160–172.

2. Wolfe F, Clauw DJ, Fitzcharles MA, et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis Care Res (Hoboken) 2010;62:600–610.

3. Macfarlane GJ, Kronisch C, Dean LE, et al. EULAR revised recommendations for the management of fibromyalgia. Ann Rheum Dis 2017;76:318–328.

4. Lauche R, Häuser W, Jung E, et al. Patient-related predictors of treatment satisfaction of patients with fibromyalgia syndrome: results of a cross-sectional survey. Clin Exp Rheumatol 2013;31(6 Suppl 79):S34–S40.

5. Raja SN, Carr DB, Cohen M, et al. The revised International Association for the Study of Pain definition of pain: concepts, challenges, and compromises. Pain 2020;161:1976–1982.

6. Pickering G, Achard A, Corriger A, et al. Electrochemical skin conductance and quantitative sensory testing on fibromyalgia. Pain Pract 2020;20:348–356.

7. Viceconti A, Geri T, De Luca S, et al. Neuropathic pain and symptoms of potential small-fiber neuropathy in fibromyalgic patients: a national on-line survey. Joint Bone Spine 2021;88:105153.

8. Üçeyler N, Zeller D, Kahn AK, et al. Small fibre pathology in patients with fibromyalgia syndrome. Brain 2013;136(Pt 6):1857–1867.

9. Chae CS, Park GY, Choi YM, et al. Rapid, objective and non-invasive diagnosis of sudomotor dysfunction in patients with lower extremity dysesthesia: a cross-sectional study. Ann Rehabil Med 2017;41:1028–1038.

10. Burgess J, Frank B, Marshall A, et al. Early detection of diabetic peripheral neuropathy: a focus on small nerve fibres. Diagnostics (Basel) 2021;11:165.

11. Bansevicius D, Westgaard RH, Stiles T. EMG activity and pain development in fibromyalgia patients exposed to mental stress of long duration. Scand J Rheumatol 2001;30:92–98.

12. Ersoz M. Nerve conduction tests in patients with fibromyalgia: comparison with normal controls. Rheumatol Int 2003;23:166–170.

13. Wolfe F, Clauw DJ, Fitzcharles MA, et al. 2016 Revisions to the 2010/2011 fibromyalgia diagnostic criteria. Semin Arthritis Rheum 2016;46:319–329.

14. Herdman M, Gudex C, Lloyd A, et al. Development and preliminary testing of the new five-level version of EQ-5D (EQ-5D-5L). Qual Life Res 2011;20:1727–1736.

15. Bril V, Perkins BA. Validation of the Toronto Clinical Scoring System for diabetic polyneuropathy. Diabetes Care 2002;25:2048–2052.

16. Burckhardt CS, Clark SR, Bennett RM. The fibromyalgia impact questionnaire: development and validation. J Rheumatol 1991;18:728–733.

17. Feldman EL, Callaghan BC, Pop-Busui R, et al. Diabetic neuropathy. Nat Rev Dis Primers 2019;5:41.

18. Dumolard A, Lefaucheur JP, Hodaj E, Liateni Z, Payen JF, Hodaj H. Central sensitization and small-fiber neuropathy are associated in patients with fibromyalgia. Clin J Pain 2023;39:8–14.

19. Oh J. Clinical spectrum and diagnosis of diabetic neuropathies. Korean J Intern Med 2020;35:1059–1069.

20. Bair MJ, Krebs EE. Fibromyalgia. Ann Intern Med 2020;172:ITC33–ITC48.

21. Kang JH, Choi SE, Park DJ, Lee SS. Disentangling diagnosis and management of fibromyalgia. J Rheum Dis 2022;29:4–13.

22. Nijs J, George SZ, Clauw DJ, et al. Central sensitisation in chronic pain conditions: latest discoveries and their potential for precision medicine. Lancet Rheumatol 2021;3:e383–e392.

23. Walitt B, Urrútia G, Nishishinya MB, Cantrell SE, Häuser W. Selective serotonin reuptake inhibitors for fibromyalgia syndrome. Cochrane Database Syst Rev 2015;2015:CD011735.

24. Häuser W, Urrútia G, Tort S, Uçeyler N, Walitt B. Serotonin and noradrenaline reuptake inhibitors (SNRIs) for fibromyalgia syndrome. Cochrane Database Syst Rev 2013;(1):CD010292. 25. Pál E, Fülöp K, Tóth P, et al. Small fiber neuropathy: clinicopathological correlations. Behav Neurol 2020;2020:8796519.

26. Hovaguimian A, Gibbons CH. Diagnosis and treatment of pain in small-fiber neuropathy. Curr Pain Headache Rep 2011;15:193–200.

27. Porubcin MG, Novak P. Diagnostic accuracy of electrochemical skin conductance in the detection of sudomotor fiber loss. Front Neurol 2020;11:273.

28. Novak P. Electrochemical skin conductance correlates with skin nerve fiber density. Front Aging Neurosci 2016;8:199.

29. Cascio MA, Mukhdomi T. Small fiber neuropathy. Treasure Island (FL): StatPearls, 2022. 30. Vecchio M, Chiaramonte R, Romano M, Pavone P, Musumeci G, Mauro GL. A systematic review of pharmacologic and rehabilitative treatment of small fiber neuropathies. Diagnostics (Basel) 2020;10:1022.

31. Cheng CW, Wong CS, Hui GK, Chung EK, Wong SH. Fibromyalgia: is it a neuropathic pain? Pain Manag 2018;8:377–388.

32. Latremoliere A, Woolf CJ. Central sensitization: a generator of pain hypersensitivity by central neural plasticity. J Pain 2009;10:895–926.

33. Seybold VS. The role of peptides in central sensitization. Handb Exp Pharmacol 2009;(194):451–491.

34. Chang CT, Jiang BY, Chen CC. Ion channels involved in substance P-mediated nociception and antinociception. Int J Mol Sci 2019;20:1596.

35. Paredes S, Cantillo S, Candido KD, Knezevic NN. An association of serotonin with pain disorders and its modulation by estrogens. Int J Mol Sci 2019;20:5729.

36. Stratz T, Fiebich B, Haus U, Müller W. Influence of tropisetron on the serum substance P levels in fibromyalgia patients. Scand J Rheumatol Suppl 2004;119:41–43.

37. Al-Nimer MSM, Mohammad TAM, Alsakeni RA. Serum levels of serotonin as a biomarker of newly diagnosed fibromyalgia in women: its relation to the platelet indices. J Res Med Sci 2018;23:71.

38. Platten M, Nollen EAA, Röhrig UF, Fallarino F, Opitz CA. Tryptophan metabolism as a common therapeutic target in cancer, neurodegeneration and beyond. Nat Rev Drug Discov 2019;18:379–401.

39. Kim H, Chen L, Lim G, et al. Brain indoleamine 2,3-dioxygenase contributes to the comorbidity of pain and depression. J Clin Invest 2012;122:2940–2954.

40. Wang Y, Li CM, Han R, et al. PCC0208009, an indirect IDO1 inhibitor, alleviates neuropathic pain and co-morbidities by regulating synaptic plasticity of ACC and amygdala. Biochem Pharmacol 2020;177:113926.