Foot peripheral sensory neuropathy: a frequent disabling manifestation in systemic sclerosis.

Abstract

OBJECTIVES Peripheral Sensory Neuropathy (PSN) is an under-recognized feature in systemic sclerosis (SSc). Moreover, SSc foot involvement is frequent but poorly investigated. We aimed to provide a detailed characterization of foot PSN in a large cohort of SSc patients, describing its associations with disease-specific features, physical disability, and Quality of Life (QoL). METHODS SSc patients and healthy controls (HC) comparable for age and gender, were enrolled in a cross-sectional observational case-control study. All subjects underwent a detailed quantitative sensory testing of feet evaluating touch, vibratory, thermal, and pain sensitivity; ultimately investigating the presence of large and small fiber neuropathy. Patient-reported outcomes (Scleroderma Health Assessment Questionnaire, Manchester Foot Pain and Disability Index, and Systemic Sclerosis Quality of Life Questionnaire) were administered to assess neuropathic symptoms, foot disability and QoL. RESULTS 109 SSc patients (88.1% female, median age 59.0 years) and 51 HC were enrolled. SSc patients presented with a significant impairment in each sensory parameter assessed (p≤ 0.01 for all). Foot PSN was present in 85.3% of the patients, with 80% having small fiber and 57% large fiber neuropathy; co-existing in 51.4% of the cases. PSN was associated with age, smoking, foot ulceration, disease duration and corticosteroids use. 80.6% subjects with PSN reported at least one neuropathic symptom. Patients with neuropathic symptoms reported worse physical function, worse foot disability, and more impaired QoL. CONCLUSION Foot PSN presents as a common and disabling manifestation in SSc patients, involving small and large fibres. Hence, foot PSN assessment should be included as a part of the SSc workup.