Dermatoscopy limitation and the critical role of capillaroscopy in the evaluation of systemic sclerosis and Raynaud's phenomenon among African American Veterans.

INTRODUCTION

Nailfold capillaroscopy (NFC) is a crucial tool for assessing diagnostic microvascular abnormalities in patients with Raynaud's phenomenon (RP). While dermatoscopy is a widely accepted, cost-effective screening method for systemic sclerosis (SSc), its utility depends on optimal visibility for accurate interpretation. The objective of this study was to determine if skin pigmentation affects the interpretability of nailfold evaluation.

METHODS

In an Institutional Review Board-approved study at the TVHS Hospital, patients undergoing evaluation for CTD-related RP were enrolled. 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).

RESULTS

A total of 38 United States (US) Veterans with RP were assessed; 28% (n = 11) were self-identified as African American. 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. 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.

CONCLUSIONS

In conclusion, 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.