Predictive value of nailfold capillaroscopy in the diagnosis of connective tissue diseases

We revised the clinical files of 326 patients who underwent nailfold capillaroscopy, These patients could be subdivided into 4 groups:I:patients with clinical suspicion of connective tissue disease, II:patients with isolated Raynaud's phenomenon, III:patients with existing connective tissue disease, IV:patients with acrocyanosis, chronic pernio or related disorders. The presence of megacapillaries was noted, The sensitivity of their presence for the various categories of connective tissue disease was as follows:systemic sclerosis (n = 11):100%, CREST (n = 15):73%, MCTD (n = 9):56%, dermatomyositis (n = 7):86%. Ninteen patients with megacapillaries had no final diagnosis of connective tissue disease (specificity 93.3%). The positive predictive value of the presence of megacapillaries for a scleroderma spectrum disorder (SSD) was 63.5% and the negative predictive value of a normal capillaroscopy 96.7%. We conclude that nailfold capillaroscopy can be advised to rule out SSD's.