Capillaroscopy and rheumatic diseases
The analysis of skin microcirculation in the management of rheumatic diseases
Nailfold capillaroscopy represents the best method to analyse microvascular abnormalities in autoimmune rheumatic diseases. Architectural disorganization, giant capillaries, haemorrhages, loss of capillaries, angiogenesis and avascular areas characterize >95% of patients with overt scleroderma.
Since microvascular damage and dysfunction represent early markers of systemic sclerosis and are clinically mirrored by secondary Raynaud phenomenon, the diagnostic, prognostic and therapeutic implications of microvessel morphological analysis by nailfold capillaroscopy enables the best clinical management.
Reduced capillary density on nailfold capillaroscopy predict and correlates with a high risk of developing digital skin ulcers and the presence of pulmonary arterial hypertension, and can therefore be used as a marker of systemic sclerosis severity and progression, as well as to monitorize the therapeutical effects.
The capillaroscopic aspects observed in dermatomyositis and in the undifferentiated connective tissue disease are generally reported as ‘SSc-like pattern’. The term ‘SSc pattern’ includes, all together, these sequential capillaroscopic changes typical to the microvascular involvement in systemic sclerosis.
In addition, interesting capillaroscopic changes have been observed in systemic lupus erythematosus, anti-phospholipid syndrome and Sjogren’s syndrome.
The presence of megacapillaries and a decreased capillary density are the hallmarks of the systemic sclerosis capillary pattern, which can be detected by nailfold capillaromicroscopy. Scleroderma pattern is often present in systemic sclerosis and dermato/polymyositis.
In normal conditions or in primary Raynaud phenomenon, the nailfold capillaroscopic pattern shows regular disposition of capillary loops along the nail-fold bed and no abnormal enlargements or capillary loss.
In patients with Raynaud phenomenon, however, one or more abnormal capillaroscopic findings should alert the physician to the possibility of secondary Raynaud phenomenon, owing to the presence of a previously undetected connective autoimmune disease. Morphological markers of microvascular damage include giant capillaries, micro-hemorrhages, loss of capillaries, the presence of avascular areas and angiogenesis; these features characterize more than 95% of patients with overt SSc even if they are not observed concomitantly.
A defined pattern has been reported in patients affected by dermatomyositis. This pattern, often associated with aspects of the scleroderma pattern, includes the presence of two or more of the following findings in at least two nail folds: enlargement of capillary loops, loss of capillaries, disorganization of the normal distribution of capillaries, ‘budding’ (‘bushy’) capillaries, twisted enlarged capillaries and capillary haemorrhages.
Systemic lupus erythematosus
Characteristic SLE pattern includes morphological alterations of capillary loops, venular visibility and sludging of blood with variability of capillary loop length.
Capillaroscopic changes have been observed also in primary SS. Capillaroscopic abnormalities in SS range from non-specific findings (crossed capillaries) to more specific findings (confluent haemorrhages and pericapillary haemorrhages) or SSc-type findings. The majority of SS patients with ACA (80%) present SSc-type findings. Nailfold capillaroscopy can be used as a simple non-invasive method to evaluate the microvascular abnormalities in SS patients, especially in those with RP and with ACA.