Optical microscopy and XRF maps (patient 2). (a) Optical microscopy showing red ink (higher magnification, arrow heads) in the superficial and deep dermis and a diffuse inflammatory infiltrate in the upper dermis (arrows: lower limits of the inflammatory infiltrate), HES-stained (×40 and ×400). (b, c, d) Spatial repartition of Ca, Fe and Zn based on the intensity of the XRF Kα emission. (d) Arrows point to the lower limits of the inflammatory infiltrate, in correlation with panel (a). The XRF map was acquired at 10 keV using a 10 µm step size and fast acquisition time (80 ms).