Inflammatory myopathies in childhood: correlation between nailfold capillaroscopy findings and clinical and laboratory data.

OBJECTIVE Nailfold capillaroscopy is an important tool for the diagnosis and follow-up of patients with rheumatic diseases, in particular dermatomyositis and scleroderma. A relationship has been observed in adults between improved capillaroscopic findings and reduced disease activity. Our aim was to correlate disease activity (clinical and laboratory data) and nailfold capillaroscopy findings in 18 patients with inflammatory myopathies. METHODS This prospective study included 13 juvenile dermatomyositis patients (Bohan and Peter criteria) (mean age of 8.8 years) and five patients with overlap syndrome (mean age of 15.7 years). We evaluated disease activity (skin abnormalities and muscle weakness, muscle enzymes and acute phase reactants) and its correlation with nailfold capillaroscopy findings (dilatation of isolated loops, dropout of surrounding vessels and giant capillary loops). We used a microscope with special light and magnification of 10 to 16X. RESULTS Eighteen patients underwent a total of 26 capillaroscopic examinations, seven of them on two or more occasions (13 were performed during the active disease phase and 13 during remission). Twelve of the 13 examinations performed during the active phase exhibited scleroderma pattern and 8 of the 13 examinations performed during remission were normal. Therefore, in 20 of the 26 examinations clinical and laboratory data and nailfold capillaroscopy findings correlated (p = 0.01). CONCLUSIONS Nailfold capillaroscopy is a non-invasive examination that offers satisfactory correlation with disease activity and could be a useful tool for the diagnosis and follow-up of inflammatory myopathies.