Body Mass Index Categories and Clinical-Epidemiological Profiles of Keloid Scars: A Retrospective Case-Control Study in a Tertiary Referral Hospital in Surakarta, Indonesia

Abstract

Background: Keloids are refractory fibroproliferative scars that grow beyond the original wound margin. Low-grade systemic inflammation linked to higher body mass index (BMI) has been proposed to promote keloid formation, but the clinical evidence is inconsistent.

Objective: To assess whether Asia-Pacific BMI categories are associated with keloid occurrence and to describe the clinical and epidemiological profile of keloid patients at an Indonesian tertiary referral hospital.

Methods: This retrospective case-control study at Dr. Moewardi General Hospital, Surakarta, Indonesia (January 2022 to December 2025) included 100 subjects: 78 keloid patients (ICD-10 L91.0) and 22 dermatology controls. BMI categories were underweight (<18.5 kg/m²), normal weight (18.5–22.9 kg/m²), overweight (23.0–24.9 kg/m²), and obese (≥25.0 kg/m²). Chi-square tests (Fisher’s exact test where expected counts were small) and multivariable logistic regression were used.

Results: Among 78 keloid patients, 30 (38.5%) were normal weight, 22 (28.2%) obese, 13 (16.7%) underweight, and 13 (16.7%) overweight. BMI category was not significantly associated with keloid occurrence (χ² = 0.666, p = 0.881; obese adjusted OR = 1.412, 95% CI: 0.418–4.770, p = 0.578). Sex (p = 0.244) and age category (p = 0.305) did not differ significantly. The anterior trunk was the most common site (47.4%). Wounds (29.5%) and surgical scars (28.2%) were the main triggers; intralesional triamcinolone acetonide was the main treatment (87.2%).

Conclusion: BMI category was not significantly associated with keloid occurrence, but the small control group (n = 22) limits power. Keloids were most often found at the anterior trunk and after skin injury.