Background/Purpose: Postural Orthostatic Tachycardia Syndrome (POTS) is a dysautonomia associated with chronic autonomic and neuropathic symptoms, including pain in multiple body regions, paresthesia, fatigue, brain fog, tachycardia, dizziness, and syncope. Many have co-morbid symptoms of rheumatologic disease such as arthralgia and myalgia, with a number having a family history of autoimmune conditions or hypermobile Ehrler’s Danlos syndrome (JH). Small fiber autonomic neuropathy (SFAN) affects nociceptive nerve fibers and has been noted in Fibromyalgia. The purpose of this study is to define the occurrence and associations of small fiber neuropathy in children, adolescents, and young adults (CAYA) with POTS and marked compromised quality of life.

Methods: Patients with dysautonomia presenting with neuropathic symptoms to a pediatric clinic that diagnoses and treats autonomic disease were offered epidermal skin biopsy (ESB) to test for SFAN. Electronic medical records were reviewed for those tested from December 2020-April 2022. Data collected were ESB findings, laboratory blood studies, and subjective and objective recorded clinical variables.

Results: Sixty-two records reviewed: 87% female (n=54), mean age of 16 years (range 10-21), and 95% (n=59) Caucasian race. Sixty-eight % (n=42) were positive for SFAN by EBS, 45% (n=19) of ESB positive had an antecedent inflammatory event such as infection, surgery, or head concussion, and 64% (n=27) had JH with a Beighton score ³6/9. Chi Square test for independence demonstrated a significant association between JH and ESB (x² =4.71, p=0.03). Of those that completed serum testing, 45% of the total sample were ANA positive, which correlated with a history of an inflammatory event (r=0.27, p=0.02.) Thyroid antibodies were found in 14% of ESB positive and were absent in all ESB negative. ESR and CRP were each elevated in 4 patients, with 100% those elevated ESB positive. SFAN on ESB was associated with the presence of antibodies, and ESR or CRP elevations (x² =4.70, p=0.02).

Conclusion: SFAN and the presence of blood markers of inflammation are common in CAYA with POTS; those with JH potentially more often affected. These results may suggest a secondarily associated autoimmune processes triggered by the inflammatory event. Whether treatment with an anti-inflammatory agent might benefit POTS patients with SFN needs to be explored.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/postural-orthostatic-tachycardia-syndrome-small-fiber-neuropathy-and-systemic-inflammation-are-they-related/