Incision erythema and ulceration differentiation. Erythema was differentiated from ulceration by the consistency of the wound and area affected. In the above diagram, erythema scores would include the pink area, not the maroon-hashed area. Ulceration scores would include the maroon-hashed area ( inner circles in A and B) and not the pink areas. A) Only the pink area outer ring would be included in the erythema score. Any erythema in the ulcerated area was included in the ulceration score, not the erythema score. B) The erythema score would include the sum of pink areas for each wound or affected area. Ulcerations, if more than one, would be summed similarly. This approach allowed for the distinction between red inflamed areas and areas with exposed underlying tissue.