Optical microscopy and XRF maps (patient 2). (a) Optical microscopy showing red ink in the superficial and deep dermis and a diffuse inflammatory infiltrate in the upper dermis, HES-stained (×40). Note the upper extremity of a hair follicle (arrowhead), with a circle indicating the area likely to contain the follicular bulb (not visible on this section). (b)–(f) Spatial distribution of Ti, Mn, Cr, Cu and Ni based on the intensity of the XRF Kα emission. An XRF map was acquired at 10 keV using a 10 µm step size and rapid acquisition (80 ms).