Erythema persists longer than one year in split-thickness skin graft donor sites

The recovery of skin function and appearance after harvest of split-thickness skin autografts is incompletely described. We followed the kinetics of skin restoration after a partial-thickness skin excision relative to adjacent normal skin over 12 months. Standardized donor site wounds were made on the thigh using a pneumatic dermatome in 19 consecutive Caucasian patients, median age 70 years, age range 44-86 years, who were undergoing skin graft surgery for leg ulcers. Transepidermal water loss (TEWL), erythema and pigmentation were measured quantitatively using non-invasive devices. The macroscopically healed wound was compared with adjacent normal skin at 1, 3 and 12 months. At 1 month postoperatively, TEWL was 108% (p = 0.003), erythema 145% (p < 0.0005) and pigmentation 24% (p < 0.001) higher in the wounds compared with adjacent uninjured skin. The corresponding values at 3 months were 48% (p = 0.015), 89% (p < 0.0005) and 15% (p < 0.0005). After 12 months, erythema was elevated by 36% (p < 0.0005), while TEWL (p = 0.246) and pigmentation (p = 0.211) had returned to same levels as in the surrounding normal skin. Diabetes mellitus (p = 0.024) and smoking (p = 0.017) were associated with increased TEWL of normal skin, and erythema decreased with age (rs = -0.53, p = 0.020). In conclusion, erythema appears to be the significant component contributing to long-term postoperative donor site appearance. We hypothesize that this is due to increased microvasculature.