The contribution of capillaroscopy to the differential diagnosis of connective autoimmune diseases.

Raynaud's phenomenon (RP) is one of the earliest clinical hallmarks of microvascular involvement in several connective autoimmune rheumatic diseases. The direct observation of the microvasculature with nailfold videocapillaroscopy (NVC) is useful for an early diagnosis of connective autoimmune diseases (secondary RP) and differentiation from primary (unsymptomatic) RP. Generally, to detect early pathologic capillaroscopic changes, the following parameters are considered: presence of enlarged and giant capillaries, haemorrhages, disorganization of the vascular array, ramified/bushy capillaries and loss of capillaries. Careful capillaroscopic analysis of subjects affected by primary RP can detect the earliest signs of the transition to secondary RP and thus screening procedures for further differential diagnosis within connective autoimmune diseases can be undertaken. In systemic sclerosis, the recognition of clear and different NVC morphological patterns ("early", "active", "late") should suggest including this analysis in the classification criteria of the disease.