Background: Suggested criteria for the identification of primary Raynaud phenomenon (RP) include symmetric attacks, absence of tissue ulceration, absence of an underline disease, absence of antinuclear antibodies, normal blood findings, and normal nailfold capillaries (1). Nailfold capillaroscopy (NC) is a tool that allows to distinguish between primary RP (PRP) and secondary RP (SRP) through the identification of the “early” scleroderma-pattern of microangiopathy (2). However, patients initially diagnosed as having PRP may shift to SRP during the follow-up (3).
Objectives: The aim of this study was to evaluate the transition from PRP to SRP in an Italian cohort of patients during their follow-up.
Methods: From subjects initially referred to our outpatient Unit for nailfold videocapillaroscopy (NVC) 129 patients with PRP were identified and followed-up for 27±21 months (mean age 46±18 months, mean RP duration 7±9 years). The diagnosis of PRP was achieved as specified above. The NVC diagnosis of scleroderma-pattern was based on the presence of specific “early” capillary abnormalities (i.e. giant capillaries, microhaemorrhages, and/or slight reduction of capillary density) (1,2). Patients performed the NVC every six months. The same operator performed the NVC examination in all the patients by recording also clinical and laboratory data.
Results: Based on the identification of the “early” scleroderma-pattern by NVC (2), 14.6% of patients changed from PRP to SRP during the follow-up. Interestingly, 4.6% of these patients showed at baseline a fully normal NVC pattern (transition from normal to scleroderma NVC pattern in 34±27 months), and 10% showed at baseline slight and not-specific nailfold capillary abnormalities (i.e. dystrophic capillaries and/or enlarged capillaries) (transition to scleroderma NVC pattern in 25±15 months). The duration of RP from the beginning up to the transition to secondary RP was 58±10 and 29±10 months, respectively for the two different groups.

Conclusion: Following a careful NVC analysis, we showed the progression from PRP to SRP in 14.6% of the analyzed patients. Interestingly, a recent study found that the annual incidence of transition from PRP to secondary RP was 1% when identified by diagnosis of an associated disease (3). We suggest the capillaroscopic analysis twice a year in presence of PRP, in order to early detect the transition to SRP in patients showing at the beginning a normal pattern or not-specific nailfold capillary abnormalities, as assessed by NC.
References: 1. LeRoy EC, et al. Clin Exp Rheumatol 1992;10:485–8.
2. Cutolo M, et al. Rheumatology 2004; 43: 719-26.
3. Hirschl M, et al. Arthritis Rheum 2006; 54: 1974-81.