Background/Purpose: Sarcoidosis is a multisystem granulomatous disease that can affect the nervous system in about 5% of patients. Sarcoidosis associated small fiber neuropathy (SSFN) presents with neuropathic pain, numbness, and dysautonomia resulting from damage to thinly myelinated Aδ and unmyelinated C fibers. Recent studies, using variable screening instruments, have found that the prevalence of SSFN may in fact be as high as 32.8% -81%. This variability is due to the lack of gold standard diagnostic criteria. This study explores the diagnostic approach to peripheral neuropathy in sarcoidosis patients at VCU Health Systems (VCUHS).

Methods: We searched for patients that were coded for both sarcoidosis (at least 2 visits coded with ICD-10: D86) and polyneuropathy (ICD-10 codes: G62.9, G63, G62.89) at VCUHS . In total, 211 unique medical record numbers were generated. We retrospectively reviewed clinical notes, electromyography (EMG), skin biopsies, and labs of all 211 patients in Cerner electronic health records.

Results: 52 patients had a clinical presentation of peripheral neuropathy upon further review. 69% were female, and 62% were African American. 35% had concomitant diabetes mellitus and 6% had vitamin B12 deficiency. There was no systematic diagnostic approach for any of the patients. 50% of patients had no studies (skin biopsy proven SFN or EMG). 96% of patients with available diagnostic testing had an EMG of which 68% were normal. The rest were consistent with large fiber neuropathy. 4% had skin biopsy proven SFN, half of which had an EMG which was normal. (Figure 1)

Conclusion: The majority of patients with small fiber neuropathy were diagnosed by their clinical presentation, without specific diagnostic criteria. Patients with SFN normally present with a normal EMG, however one patient with an abnormal EMG had a skin biopsy proven SFN, further emphasizing the need for more standardized diagnostic criteria. A SFN screening list has been previously validated in diagnosis of SSFN3, however it hasn’t been correlated with other studies like skin biopsies. Given the debilitating effects of SSFN on physical functioning and ultimately the quality of life of patients with sarcoidosis, it is important to utilize a more standardized diagnostic approach to identify and manage these patients.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/diagnostic-approach-to-identifying-small-fiber-neuropathy-in-patients-with-sarcoidosis/