Risk factors associated with keloid infections: A five-year retrospective study.

Keloid infections reduce patient-reported quality of life greatly. Characteristics and risk factors of keloid infections have not been thoroughly studied. So, a retrospective cohort study was conducted focusing on the potential risk factors, microbiologic cultures and histological findings. Keloid patients consulting for surgical interventions were included in this study. Data were collected from their electronic medical records. 564 patients were recruited with the keloid infection rate being 22.4%. For adult patients, age above 40 years (OR, 2.84; P = .000), disease duration of 12 years or more (OR, 3.03; P = .000), the number of keloids over 3 (OR, 1.59; P = .050) and the presence of family history (OR, 1.91; P = .027) were significantly associated with keloid infections. Suppurative keloids were located mostly in thorax (61.79%). For the under-age subgroup(n = 25), family history was frequently seen in patients with infections. Microbiologic cultures revealed a mixed spectrum of bacteria including Staphylococcus (25%), Actinomyces (30%) and Prevotella (10%). The rate of epidermoid cysts was 19.7% in histological examination. Age > 40 years, disease duration ≥12 years, the number of keloids >3 and the presence of family history are risk factors for keloid infections.