Clinically relevant differences between primary Raynaud's phenomenon and secondary to connective tissue disease

Raynaud's phenomenon (RP) is a symptom complex associated with digital vascular compromise. Our aim was to examine for clinically relevant differences between primary RP (PRP) and secondary RP (SRP) to connective tissue disease.

We report cross-sectional results from the Patient Survey of experiences of Raynaud's Phenomenon (PASRAP), which aimed to explore the broad-ranging impact of RP. The survey was widely distributed online including via social medial. Participation was voluntary and responses were anonymous.

1229 respondents completed PASRAP with self-reported RP: PRP 218 (17.7 %) and SRP 1011 (82.3 %) of which 903 (92.9 %) Systemic Sclerosis. The mean (SD) age was significantly lower in respondents with PRP (41.7 [11.8] vs 54.2 [12.4] years, P<0.0001). During attacks, more subjects with SRP reported cyanotic colour changes (92.2 % vs 86.5 %, P=0.0089). Patients with PRP experienced more pain (72.1 % vs 55.9 %, P<0.0001), numbness (80.3 % vs 69.4 %, P=0.0016), stinging/throbbing (93.4 % vs 80.8 %, P<0.0001), and tingling (84.0 % vs 77.5 %, P=0.0345). Only half of respondents' symptoms were adequately controlled by their current medication(s), more commonly in SRP (55.2 % vs 45.2 %, P=0.0084). There were important differences in the triggers, number, and seasonal variation of RP attacks.

There are clinically relevant differences between PRP and SRP concerning the multifaceted lived patient experience of RP. Neurosensory symptoms are more common in PRP. Patients with SRP are older and present with more colour changes, overrepresented by cyanosis, and with less complete resolution of symptoms between attacks. These data provide novel insights for future RP clinical trial design.