Abstract

Clinical rheumatologists frequently get patients with Raynaud's phenomenon (discoloration of extremities upon exposure to cold or stress) referred. The challenge is to distinguish patients with a primary Raynaud's phenomenon (not connected to any connective tissue disease) from patients with a secondary Raynaud's phenomenon (due to a connective tissue disease).

A large 20-year follow-up study (Koenig Arthritis Rheum 2008) of patients presenting at baseline with merely the Raynaud's phenomenon and no sign of a connective tissue disease has taught the scientific community that if a CTD is to develop in such a population then it is systemic sclerosis. Subsequently it makes sense to screen for SSc in a Raynaud's phenomenon population.

In 1992 LeRoy and Medsger proposed criteria to distinguish primary from secondary Raynaud's phenomenon. Retrospective validation of these criteria allow correct classification of a patient in one clinical consultation in 89%. Amongst other criteria, a “normal” capillaroscopy is obligatory to be able to speak of a “primary” Raynaud's phenomenon. Conversely patients with a secondary RP due to SSc have the combination of a SSc-specific antibody and a scleroderma pattern on capillaroscopy.

These criteria have prospectively been validated. The triade of RP, SSc-specific antibody and scleroderma pattern on capillaroscopy has a high positive predictive value for the development of SSc, whilst the absence of SSc-specific antibodies and a scleroderma pattern has a high negative predictive value for the non-occurrence of SSc.