Clinical and epidemiological analysis of keloids in Chinese patients

Keloids are common abnormally raised fibroproliferative lesions that can occur following even minor cutaneous trauma. There are limited data on Chinese patients with keloids, and the purpose of our study was to investigate the clinical and epidemiological features of keloids in Chinese patients. Assessment was performed by unified, designed questionnaires. A total of 715 patients were enrolled and statistical analysis and heritability were performed using EPI INFO 6.0, SPSS13.0 and Falconer's method. Keloids occurred typically between the ages of 10 and 30 years, and the mean age of initial onset was 21.14 ± 13.45 years in females and 22.55 ± 11.36 years in males. The difference in the mean age of onset was not significant between males and females (p > 0.05). A greater severity of keloids was observed in the positive history family group than in the negative history family group, and this difference was statistically significant (χ (2) = 10.889, p < 0.05). The formation of keloids in multiple anatomical sites was found to be significant in the positive family history group. This difference was statistically significant (χ (2) = 15.47, p < 0.001). The prevalence of keloids in first-, second- and third-degree relatives of the proband with keloids was 7.62, 0.38 and 0.035 %, respectively. These results were higher than those in controls and the difference of the prevalence rates of first- and second-degree relatives between probands and controls was significant (χ (2) = 224.63 and 12.078, respectively, p < 0.001). The heritability of keloids in first-, second- and third-degree relatives was 72.45, 40.55 and 17.07 %, respectively. Our findings revealed that the most severe forms of keloids were observed in the probands with positive family history, and the heritability in first-degree relatives of probands was 72.45 %. It is certain, therefore, that genetic factors play a role in the hereditary composition of keloids.