Assessment of foot impairment in systemic sclerosis: a cross-sectional study

Objectives To assess foot function in SSc and its association with socio-demographic and clinical factors. To evaluate mobility, foot alterations, foot pain, and foot care in these patients. Methods Consecutive SSc patients underwent structured interviews and physical examinations. Disability was assessed using the HAQ disability index (HAQ-DI) and the Scleroderma HAQ (SHAQ). Foot function was measured using the Foot Function Index (FFI), foot pain using a numeric pain scale (NPS), and mobility using the Timed-Up-and-Go test (TUG). Results A total of 101 patients were included. Forefoot pain was observed in 50.5%, hindfoot pain in 31.7%, foot ulcers in 6.9%, foot plantar callosities in 38.6%, foot arthritis in 2.97%, hallux valgus in 9.9%, claw toes in 5%, and valgus ankle in 3% of patients. The mean FFI was 3.54 (2.6), the mean NPS was 6.08 (+/- 3.58), and the mean TUG test result was 10.52 (+/- 6.5) seconds. Higher FFI scores, increased NPS, and prolonged TUG were associated with RP severity, SHAQ and HAQ-DI. Of the 101 patients, 36.6% of patients reported never having had their feet examined, and only 32.7% had had their feet examined within the past year. Conclusion Foot dysfunction and pain are common in SSc. Higher FFI scores, increased pain, and prolonged TUG duration were linked to disability (HAQ-DI and SHAQ). These analyses should be considered exploratory and require confirmation in external cohorts. Routine foot examinations were lacking in clinical practice. Improved attention for evaluating and caring for the feet in SSc patients is needed.