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Glossary

Nailfold capillaroscopy

A close-up look at the tiny blood vessels at the base of your fingernail. It takes minutes, it doesn't hurt, and it's better at ruling a disease out than ruling one in.

A magnifier on your fingernail bed and about ten minutes is the whole of this test. It reads the smallest blood vessels in your body. What it finds there says a good deal about what comes next, and it says more when it comes back normal than when it doesn't.

Quick answerNailfold capillaroscopy is a close-up look at the tiny vessels at the base of your nail. The whole thing takes minutes and it doesn't hurt at all. In one study of 759 people with Raynaud's, a normal result ruled out the scleroderma pattern correctly 88 percent of the time.
This test reassures better than it diagnoses, which is the opposite of how most tests work. In that study the absence of a scleroderma pattern had a negative predictive value of 88 percent, while its positive predictive values were low. So a normal result is real reassurance and an abnormal one starts a conversation rather than ending it. One reason is that the scleroderma pattern turns up in several illnesses, showing in 88 percent of people with systemic sclerosis and in 13 percent of people with rheumatoid arthritis.

What the test is

Nailfold capillaroscopy is a close-up look at the tiny blood vessels at the base of your fingernail. A drop of oil goes on the skin, and then a magnifier or a small video camera looks at it. That is genuinely the whole of the test, start to finish.

Several of your fingers get checked, and the whole thing is over in minutes. Nothing goes into you, nothing gets cut, and people are usually surprised by how little there is to it. The vessels being looked at are called capillaries, and they're the smallest in your body, where blood finally reaches the tissue it feeds.

What an abnormal result is worth

Less on its own, because the scleroderma pattern isn't confined to scleroderma. It turns up across several illnesses, and that study is where the numbers for it come from. It found the pattern in 88 percent of those with systemic sclerosis, 71 percent with mixed connective tissue disease, 33 percent with primary Sjogren's syndrome, 17 percent with lupus, and 13 percent with rheumatoid arthritis.

So an abnormal result cuts the field down without settling it. That's why the next step is a conversation rather than a conclusion. An abnormal capillaroscopy is not a diagnosis, and the people who order it don't read it that way either.

Two other studies show how far the pattern spreads. One followed 190 people with antisynthetase syndrome, a scleroderma pattern showed in 35.3 percent of them, and of those only 47 percent had Raynaud's at all. One followed 41 young people with childhood-onset lupus, small vessel damage showed in 68.3 percent, and a scleroderma pattern showed in 7 who had no scleroderma symptoms whatsoever.

What the stage predicts

This is where the test earns its place, and several studies point in one direction. Read the ranges as well as the numbers, because some of the ranges here are very wide. One study followed 94 people with systemic sclerosis for three years.

An active pattern at the start predicted a combined bad outcome at an odds ratio of 3.305, at P equals 0.043. A late pattern predicted it at 6.900, at P equals 0.023. That outcome meant lung function falling, skin score worsening, a first finger ulcer, or death.

One study followed 86 people, where a late pattern predicted finger ulcers at an odds ratio of 6.03 from 1.52 to 23.86. It predicted calcium deposits in the tissues at 27.22 from 5.56 to 133.33, and after adjusting for disease duration and sex that figure came out at 42.89 from 5.53 to 332.85. Read the range, not the number there, because 5.53 and 332.85 are very far apart.

One study followed 36 people for five years. Of those, 19 developed new finger ulcers, and a late pattern predicted that at a hazard ratio of 7.087 from 1.989 to 25.246. That interval is narrower than most on this page, which makes it one of the firmer findings here.

One study followed 387 people, where having two or more finger ulcers was associated with the late and active patterns at odds ratios around 2 to 2.6. A skin thickening score above 15 was associated with them far more strongly, at 32.007 and 18.390. That's a much bigger effect than the ulcer counts showed.

Watching it change

The test gets repeated over time, and the change between one look and the next holds its own information. That makes a second look considerably more than a repeat of the first. One study re-examined 34 people with early systemic sclerosis after three years, and 8 of them, or 23.5 percent, had progressed to definite disease.

The capillaroscopy measures had worsened in 55.9 percent of the group overall. Two specific changes separated those who progressed from those who didn't. More giant vessels came in at P equals 0.02, and a worsening loss score at P equals 0.002.

On multivariate analysis, one thing independently predicted going on to definite disease, and that was an active or late pattern at the start. The odds ratio was 30.0, with the true value somewhere from 2.1 to 421.1. That range is vast, which is what 34 people gives you, though the direction has since been found repeatedly.

One more study makes a quieter point that's worth having. When infusions were interrupted during a pandemic quarantine, lower capillary density predicted whose Raynaud's got worse. Each one-unit rise in density was associated with a 44 percent fall in the odds of worsening, at 0.56 from 0.36 to 0.97.

Common misconceptions.

Myth. An abnormal result means I have scleroderma.

Reality. It doesn't, because the scleroderma pattern turns up in other illnesses too. One study of 759 people found it in 88 percent of those with systemic sclerosis and in 71 percent of those with mixed connective tissue disease. It also showed in 33 percent with Sjogren's, 17 percent with lupus, and 13 percent with rheumatoid arthritis, and its positive predictive values were low.

Myth. A normal result doesn't tell you much.

Reality. It tells you more than an abnormal one does, which is the unusual part of this test. In that study the absence of a scleroderma pattern was correct 88 percent of the time, and that's the direction this test is strong in. If you've been sent for it because of cold, color-changing fingers, a normal result is the most reassuring thing it can give you.

Myth. All the features they look at count alike.

Reality. They don't, and one study ranked them against each other. Capillary loss separated the groups best at 0.905, with widened vessels next at 0.863 and giant vessels at 0.835. Tiny bleeds managed 0.720 and branching vessels 0.604, which is close to useless, so how many vessels have gone counts for more than how odd the survivors look.

Myth. It's just a snapshot of today.

Reality. It predicts things, and one study followed 34 people with early disease for three years to show it. An active or late pattern at the start predicted going on to definite systemic sclerosis, at an odds ratio of 30.0 from 2.1 to 421.1. That range is enormous, which is what 34 people buys you, though the direction has been found repeatedly.

Myth. It's only useful in systemic sclerosis.

Reality. It turns up in other illnesses too, and one study looked in an unexpected place. It followed 41 young people with childhood-onset lupus, and small vessel damage showed in 68.3 percent of them, with a scleroderma pattern in 7. Not one of those 7 had any scleroderma symptoms, and large bleeds were associated with disease activity scores and with kidney involvement.

Related terms.

References.

  1. van Roon AM; Huisman CC; van Roon AM et al. Abnormal Nailfold Capillaroscopy Is Common in Patients with Connective Tissue Disease and Associated with Abnormal Pulmonary Function Tests. J Rheumatol. 2019;46:1109-1116. 10.3899/jrheum.180615Journal Article
  2. Bournia VK; Kottas K; Panopoulos S et al. Differential performance of nailfold video capillaroscopic parameters in the diagnosis and prognosis of systemic sclerosis. Clin Exp Rheumatol. 2020;38 Suppl 125:29-39. PMID 31969216Cross-sectional diagnostic study with follow-up
  3. Zumstein Camargo C; Kayser C. Capillaroscopy changes are associated with disease progression in patients with early systemic sclerosis: A prospective study. Int J Rheum Dis. 2019;22:1319-1326. 10.1111/1756-185X.13592Prospective study of 44 patients with early systemic sclerosis by LeRoy and Medsger 2001 criteria
  4. Martins A; Pimenta S; Oliveira D et al. Can microvascular damage predict disease severity in patients with systemic sclerosis?. Reumatol Clin (Engl Ed). 2024;20:366-371. 10.1016/j.reumae.2024.07.006Retrospective study of 86 patients with systemic sclerosis who had nailfold videocapillaroscopy within 6 months of diagnosis
  5. Boulon C; Aiouaz S; Blaise S et al. Correlation between capillaroscopic classifications and severity in systemic sclerosis: results from SCLEROCAP study at inclusion. Clin Exp Rheumatol. 2019;37 Suppl 119:63-68. PMID 31172926Multicentre prospective study
  6. Colalillo A; Vaiarello V; Pellicano C et al. Color Doppler Ultrasonography of digital arteries and digital ulcers development in systemic sclerosis. Microvasc Res. 2021;138:104210. 10.1016/j.mvr.2021.104210Comparative study of 36 patients with systemic sclerosis examined by both nailfold videocapillaroscopy and colour Doppler ultrasound of the proper palmar digital arteries
  7. Schonenberg-Meinema D; Bergkamp SC; Nassar-Sheikh Rashid A et al. Nailfold capillary abnormalities in childhood-onset systemic lupus erythematosus: a cross-sectional study compared with healthy controls. Lupus. 2021;30:818-827. 10.1177/0961203321998750Cross-sectional study of 41 patients with childhood-onset systemic lupus erythematosus against 41 healthy controls matched for ethnic background
  8. Sebastiani M; Triantafyllias K; Manfredi A et al. Nailfold Capillaroscopy Characteristics of Antisynthetase Syndrome and Possible Clinical Associations: Results of a Multicenter International Study. J Rheumatol. 2019;46:279-284. 10.3899/jrheum.180355Multicentre international retrospective study of nailfold videocapillaroscopy images from 190 patients with antisynthetase syndrome
  9. Binda M; Moccaldi B; Tirelli F et al. Nailfold videocapillaroscopy in the assessment of juvenile connective tissue diseases. Clin Exp Rheumatol. 2026;44:582-588. 10.55563/clinexprheumatol/6bz7okNailfold videocapillaroscopy in children followed at one paediatric rheumatology unit
  10. De Lorenzis E; Natalello G; Verardi L et al. Sudden winter iloprost withdrawal in scleroderma patients during COVID-19 pandemic. Microvasc Res. 2022;144:104404. 10.1016/j.mvr.2022.104404Survey of 50 systemic sclerosis patients who stopped intravenous iloprost infusions during COVID-19 quarantine

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This page gathers the published research on this subject into one place. The studies behind it were published between 1989 and 2026, and every figure links to the paper it came from. Those studies were peer reviewed. This summary of them was not. Dr. Sarah Luebker is reviewing these pages one at a time and has not reached this one yet, so it carries no medical review date and nothing here is her opinion or her advice to you. Each page gets updated as she reaches it. It is here in the meantime because the science is worth having in one organized place that is easy to find and easy to read. Talk to your own clinician before acting on any of it.