educational medical diagram showing 4 levels of localized inflammatory redness around an injection site, four side-by-side panels, same skin tone, same distance, same centered puncture point, panel 1 no redness, panel 2 small faint pink halo, panel 3 medium clearly visible red halo, panel 4 large intense dark red halo, clean background, soft realistic shading, consistent lighting, no extra objects, no text Mehr sehen