To the Editor:
Rheumatoid arthritis (RA) is commonly cited as a cause of secondary Raynaud’s phenomenon (RP). Yet there are few studies estimating the prevalence of RP in RA, and those found very different prevalences, ranging from 2.7%1 to 17.2%2. Therefore RP may be no more common in patients with RA than in the general population, in whom reported prevalence also varies but is probably in the order of 4.6%3 to 19%4. Differences in the definition of RP and in the populations studied will contribute to this wide range. Irrespective of whether RP is overrepresented in patients with RA, there is no doubt that a proportion of patients with RA have RP; there are reasons why RP might be more severe in patients with RA: a procoagulant tendency5, endothelial injury/activation5, and reduced vasodilation6 are all thought to occur in RA, and all have been implicated in the pathogenesis of RP7.
In patients with systemic sclerosis, RP is associated with significant functional disability8 …