Prevalence of hypertrophic scar formation and its characteristics among the Chinese population

Each year in Hong Kong, about 350,000 surgical procedures are conducted for various types of conditions. Previous review indicated that the prevalence of hypertrophic scar among Caucasians ranged from 15% to 63% and that the incidence was even higher among non-Caucasians. This study aims to find out the prevalence rate of hypertrophic scar among the Hong Kong Chinese population after standardized surgical procedures. A systematic and objective scar measurement protocol is implemented in this study. The spectrocolorimeter, Miniscan XE plus was used to measure the scar pigmentation based on the theory of the CIE colour model. The tissue ultrasound palpation system (TUPS) was employed to measure scar thickness. From May 2001 to December 2003, 154 patients, who received surgical intervention at the Department of Orthopaedics and Traumatology of a large regional hospital, were invited to join a scar-screening test. One hundred and fifteen patients (74.67%) were found to have signs of hypertrophic scar based on thickness, pliability, pigmentation and vascularity (using the Vancouver scar scale (VSS) score). One hundred and one patients consented to have more comprehensive scar assessment. Results indicated that the scar thickness was 4.91 ± 1.03 mm. Compared with the adjacent normal skin, the color of hypertrophic scar was significantly different in terms of lightness (d.f. = 100, t = -19.36, p < 0.01), redness (d.f. = 100, t = 15.75, p < 0.01) and yellowness (d.f. = 100, t = -11.48, p < 0.01) using paired t-test analysis. Fourtysix point five percent and 33.7% among patients reported pain (2.19 ± 2.74) and itchiness (1.47 ± 2.53) over the scar. The objective scar assessments showed that more than 70% of scars had increase in thickness and pigmentation after surgery. More than 40% of patients reported pain and itchiness. The results showed that more than 70% of the scars in the HK Chinese population had become hypertrophic in terms of pigmentation, thickness and physical symptoms such as pain and itchiness 1 month after the surgical intervention. More long-term follow up study should be done to find out the prevalence and that it is essential to provide early intervention before the scar becomes problematic in management.