NASHVILLE, TN — Nailfold capillaroscopy (NFC) is a crucial tool for assessing diagnostic microvascular abnormalities in patients with Raynaud’s phenomenon (RP). A recent study sought to determine whether skin pigmentation affects the interpretability of nailfold evaluation.
“While dermatoscopy is a widely accepted, cost-effective screening method for systemic sclerosis (SSc), its utility depends on optimal visibility for accurate interpretation,” according to researchers from Vanderbilt University Medical Center and the Nashville VAMC.
For the study published in Seminars in Arthritis and Rheumatism, images were captured using two devices: a 200X dermatoscope (smartphone focus) and a 250X Smart G-Scope (USB automatic focus). Two capillaroscopy experts independently classified each image for clarity and the overall pattern (scleroderma or non-scleroderma). Skin pigmentation was assessed using the Fitzpatrick classification (I-VI).1
Overall, 38 U.S. veterans with RP were assessed; 28% of those self-identified as African American. The results indicated that dermatoscopy analysis yielded blurry images in 63.6% (7/11) of patients with Fitzpatrick skin tones IV, V and VI, compared to 37% (10/31) in skin tones I, II and III. On the other hand, the USB-capillaroscope improved interpretability across the entire cohort, especially in skin tones IV, V and VI. “Notably, a Scleroderma (SD)-pattern was detected by the USB-capillaroscope in 4 of the 5 studies that had been uninterpretable with the dermatoscope,” according to the authors.
The researchers concluded that dermatoscopy resulted in a high rate of uninterpretable examinations in patients with RP, particularly among African-American veterans. “The USB-capillaroscope device significantly improved interpretability, underscoring that relying solely on dermatoscopy as a screening tool may lead to underdiagnosis of SSc,” they wrote.
To identify RP, microvascular abnormalities are found on capillaroscopic evaluation of the nailfold, which indicates underlying connective tissue diseases. Nailfold capillaroscopy (NFC) is a “non-invasive, cost effective, and essential tool for the evaluation of microvascular changes in patients with RP, playing a critical role in differentiating primary from secondary RP,” according to background information in the report.
“While dermatoscopy has gained acceptance as a screening method for nailfold microvascular assessment in systemic sclerosis (SSc) due to its accessibility and affordability, existing guidelines emphasize the importance of high-quality image acquisition for accurate interpretation,” the authors advised. “Previous studies have described a high percentage of unclassifiable images with dermatoscopy even in general population. Furthermore, anecdotal evidence and clinical observations suggests that skin pigmentation might interfere with clarity and interpretability of dermatoscopy images, potentially leading to diagnostic challenges in diverse patient populations.”
Those concerns led to the current study, they said.
- Maldonado G, Cutolo M, Frech T, Radic M, Snow M, Smith V. Dermatoscopy limitation and the critical role of capillaroscopy in the evaluation of systemic sclerosis and Raynaud’s phenomenon among African American Veterans. Semin Arthritis Rheum. 2026 Jun;78:152961. doi: 10.1016/j.semarthrit.2026.152961. Epub 2026 Mar 5. PMID: 41812319.
