Colour changes in the feet: a sign of autonomic symptoms in systemic sclerosis

Abstract

Objectives: Patients with autonomic dysfunction, or dysautonomia, often report discolouration of their dependent extremities, which is thought to be from venous pooling or acrocyanosis. A subset of patients with SSc are affected by dysautonomia but may be challenging to identify. We sought to determine whether patients with SSc who report discolouration in their feet have a higher burden of autonomic symptoms, including orthostatic, gastrointestinal (GI), urinary, secretomotor and pupillomotor.

Methods: 167 patients with SSc completed the Composite Autonomic Symptom Score (COMPASS)-31 survey, which queries whether the patient experiences discolouration of the feet or hands. We compared the COMPASS-31 subdomain scores between SSc patients with and without foot discolouration. Seventy-nine patients with postural orthostatic tachycardia syndrome (POTS) also completed the COMPASS-31 questionnaire for comparison.

Results: We found that extremity discolouration is common in POTS and more often affects the feet, whereas in SSc, the hands are more frequently involved; 62% of SSc patients report colour changes in their feet. These patients are more likely to have other autonomic symptoms, including orthostatic (11.7 ± 10.6 vs 8.6 ± 9.9, P = 0.06), GI (11.3 ± 4.3 vs 8.8 ± 4.3, P = 0.0003), urinary (1.4 ± 1.5 vs 0.8 ± 1.3, P = 0.002) and secretomotor (7.0 ± 3.8 vs 5.9 ± 3.8, P = 0.06) symptoms. These associations persist in a multivariable model after adjusting for potential confounders.

Conclusion: Dependent extremity discolouration is common in dysautonomia. Patients with SSc who report colour changes in their feet are more likely to report other symptoms of autonomic dysfunction.

Keywords: COMPASS-31; Raynaud’s; SSc; acrocyanosis; dysautonomia; scleroderma.