Objectives: To establish the prevalence of the associated secondary diseases in patients with Raynaud's phenomenon (RP) attending a rheumatology specialty centre and to determine the frequency with which a secondary illness develops in those having RP, in absence of a well-defined secondary cause.
Methods: 118 consecutive patients were evaluated. Medical history, physical and laboratory investigations entered into a database. Patients with primary RP and patients with RP who did not fulfil any diagnostic criteria for inclusion in a secondary form were followed up over a three-year period.
Results: 63 RP patients were found with related conditions. 35 patients met criteria for inclusion in a primary RP group, 20 patients had 'unclassifiable' RP, of which two (10%) developed a well-defined disease. None of the primary RP patients developed a secondary disease.
Conclusions: This study shows that less than 50% of patients with RP attending a rheumatology specialty centre have a connective tissue disease. Patients with isolated RP appear to have a benign disease, since primary RP remains as such, and only a small percentage of patients with 'unclassifiable' RP evolve into a well-defined CTD.