Modified Patient and Observer Scar Assessment Scale

The modified POSAS Patient Scale^13,14 is a six-item scar self-assessment scale with a score range of 1–10, where the lower the score, the better the scar feature. The markers assessed are pain, itching, color, stiffness, thickness, and irregularity. The lowest score corresponds to a situation similar to that of the normal skin (ie, normal pigmentation, no itching), whereas the highest one represents the largest difference from normal skin (ie, the worst imaginable scar or sensation). The total score can range from 6 to 60. Unlike in the original POSAS Patient Scale, the “overall opinion” assessment is not included in the sum score. All of the items are easy to understand and the observer provides the essential information, to allow an easy and reliable patient self-assessment, without influencing the patient’s choice.

The original POSAS Observer Scale consists of seven items (vascularity, pigmentation, thickness, relief, pliability, surface area, and overall opinion).

In our study, these seven were reduced to four by excluding the following parameters: “surface area,” “relief” (as these were not considered pertinent to a linear and fresh surgical scar resulting from the keloid excision), and “overall opinion.”

The vascularity was assessed through the intensity of the capillary refill after blanching the scar with a sheet of plexiglass; the same technique allowed for the assessment of the pigmentation after the contribution of vascularity was eliminated; the thickness was assessed with a caliper as the average distance between the epidermal surface of the scar and the epidermal level of the surrounding healthy skin; pliability was measured as the suppleness of the scar assessed by wrinkling the scar between the thumb and index finger. All items were scored on a scale ranging from 1 (like normal skin) to 10 (worst scar imaginable). The sum of the scores of the four items resulted in the POSAS Observer total score. All of the parameters were always compared with those of the normal skin on a comparable anatomic site.

The examiner assessed and scored the scar without being influenced by the patient’s perception.

The total score of both scales was simply calculated by summing up the respective total scores.