Daoudi K, Kersten BE, van den Ende CHM, et al. - Researchers assumed that photoacoustics and high-frequency ultrasound can identify (early) systemic sclerosis (SSc) patients from individuals with primary Raynaud’s phenomenon (PRP) by assessing oxygenation of the fingertip and skin thickening. Measurements of oxygenation and skin thickness of the third finger were compared between (early) SSc patients and PRP individuals and healthy controls. Researchers applied spearman rank correlation to examine a relationship between capillary density and oxygen saturation of the fingers. The study included a total of 31 adults: twelve patients with SSc, 5 patients with early SSc, 5 volunteers with PR, and 9 healthy controls. This study’s findings demonstrated that photoacoustic and high-frequency ultrasound could help to distinguish between (early) SSc, PRP, and healthy individuals in both oxygenation and skin thickening.