Background: Keloid is a benign fibrous growth, which presents in scar tissue of predisposed individuals. It is a result of irregular wound healing, but the exact mechanism is unknown. However, several factors may play a role in keloid formation. To date, there are no studies of keloids in Syria, and limited studies on Caucasians, so we have investigated the risk factors of keloids in Syrians (Caucasians), and this is the main objective of this study.
Methods: Diagnosis of keloids was clinically made after an interview and physical examination. We did a histopathological study in case the physical examination was unclear. The following information was taken for each patient; sex, Blood groups (ABO\Rh), cause of scarring, anatomical sites, age of onset, number of injured sites (single\multiple) and family history.
Results: We have studied the clinical characteristics of 259 patients with keloids,130 (50.2 %) females and 129 (49.8 %) males. There were 209 (80.7 %) patients with keloids in a single anatomical site compared to 50 (19.3 %) patients with 130 keloids in multiple anatomical sites, 253 (97.68 %) patients with keloids caused by a single cause for each patient compared to 6 (2.32 %) patients with keloids caused by two different causes for each patient. Keloids could follow any form of skin injury, but burn was the most common (28.68 %). Also, keloids could develop at any anatomical sites, but upper limb (20 %) followed by sternum (19.17 %) was the most common. Over half of the patients developed keloids in the 11-30 age range. 19.3 % (50/259) of patients had family history, 76 % (38/50) of them had keloids located in the same anatomical sites of relative, also, 66 % (33\50) of them had keloids caused by the same cause. The following information was found to be statistically significant; people with blood group A (p = 0.01) compared with other blood groups, spontaneous keloids in patients with blood group A (p = 0.01), acne in males (p = 0.0008) compared to females, acne in someone who has a previous acne keloid (p = 0.0002), burn in someone who has a previous burn keloid (p = 0.029), family history, especially for spontaneous (p = 0.005), presternal (p = 0.039) and shoulder (p = 0.008) keloids, people in second and third decades (p = 0.02) (p = 0.01) respectively.
Conclusion: Age of onset, sex, cause of scarring, blood groups, anatomical site, presence of family history and the number of site (multiple\single) were significant in keloid formation in Syrians.
Keywords: Age of onset; Anatomical site; Blood groups; Cause of scarring; Family history; Keloids; Multiple sites; Risk factors; Single site; Syrians.