Rheumatologists Find Nailfold Capillaroscopy an Increasingly Useful Diagnostic Tool

In 2013, the ACR and EULAR published a new system of classification for SSc. For the first time, abnormal nailfold capillaries were included as part of the scoring.¹⁵ Dr. Herrick believes this change has provided a huge incentive for rheumatologists to start using the technique. “This is because abnormal nailfold capillaries score 2 out of the 9 points required to fulfill the criteria. In consequence, this behooves anyone whose clinical practice involves diagnosing systemic sclerosis-spectrum disorders to be familiar with the technique.”

The new classification criteria have increased sensitivity compared with earlier scoring systems, increasing the number of early and mild cases of SSc, which can be successfully recognized.¹⁶

Dr. Herrick views lack of familiarity with the technique as a major barrier making nailfold capillaroscopy an underutilized method in clinical practice. However, she explains that this is changing because of increasing numbers of publications in rheumatology journals relating to nailfold capillaroscopy, posters and oral presentations on capillaroscopy at all the main rheumatology meetings and training courses on capillaroscopy.

Dr. Herrick

Cost is another perceived barrier to use. “High-magnification videocapillaroscopy systems (which are considered the gold standard) can be costly, although these are now relatively less expensive than previously with some videocapillaroscopy systems being in the order of £8,000–10,000 [roughly $10,000–13,000 USD],” Dr. Herrick notes. “However, for routine practice, other options are much less expensive. Definite abnormalities can often be seen using simple handheld systems, such as a dermatoscope and low-cost USB microscope.”

What Technique to Use?

A rheumatologist looking to incorporate a method of viewing nailfold capillaries may wonder which method makes the most sense. The answer probably depends on the needs of the specific practitioner.

Ongoing studies are comparing videocapillaroscopy (high magnification, usually 200X) with dermoscopy (low magnification, usually approximately 10X).⁶ Dr. Herrick notes, “The evidence available so far suggests that dermoscopy is likely to be slightly less sensitive (but more specific) than videocapillaroscopy in detecting scleroderma-pattern abnormalities.”

Dermatoscopes provide an easy method of evaluation for nail capillary pathology, but rheumatologists do not use them as commonly. This may be because rheumatologists are not as familiar with dermatoscopes and their diagnostic abilities in this setting.⁶

“In my opinion, a dermatoscope or low-cost USB microscope is likely to be the best option for a general rheumatologist, because these allow a very rapid look at the nailfolds in a busy outpatient clinic,” recommends Dr. Herrick.

However, she cautions that subtle abnormalities can be missed with this method. “For someone who is referred a large number of patients with systemic sclerosis, then a videocapillaroscopy system has the advantage of giving a more detailed view of the capillaries and allows measurement of capillary density.” She also notes that a videocapillaroscopy system is the best option for clinical researchers, who often wish to quantify abnormality, something not currently possible with low-magnification systems.