The Clinical Features of Painful Small-Fiber Neuropathy Suggesting an Origin Linked to Primary Sjögren's Syndrome

Pain Pract. 2019 Apr;19(4):426-434. doi: 10.1111/papr.12763. Epub 2019 Feb 6.


Objective: We attempted to determine whether clinical features could differentiate painful small-fiber neuropathy related to primary Sj€ogren's syndrome (pSS-SFN) from idiopathic SFN (idio-SFN).

Methods: Validated clinical questionnaires and neurophysiological investigations specific for pain and SFN assessment were performed in 25 patients with pSS-SFN and 25 patients with idio-SFN.

Results: Patients with idio-SFN had more frequent severe burning sensations and higher mean anxiety scores and daily pain intensity compared to patients with pSSSFN. Conversely, patients with pSS-SFN had reduced electrochemical skin conductance measured by Sudoscan_, and almost half of them had the sensation of walking on cotton wool.

Conclusion: Our results suggest that idio-SFN more specifically involved small sensory fibers than pSS-SFN, in which subtle dysfunction of larger sensory fibers and damage of distal autonomic sudomotor innervation may occur. A practical algorithm is proposed to help to differentiate SFN associated with pSS from idio-SFN, based on information very easy to obtain by clinical interview.

Keywords: clinical neurophysiology; pain descriptors; questionnaire; restless leg syndrome; sicca syndrome; skin conductance; small-fiber neuropathy.

MeSH terms

  • Adult
  • Aged
  • Algorithms*
  • Diagnosis, Differential
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neuralgia / diagnosis*
  • Neuralgia / etiology
  • Sjogren's Syndrome / complications*
  • Small Fiber Neuropathy / diagnosis*
  • Small Fiber Neuropathy / etiology
  • Surveys and Questionnaires