Laser hair removal complications and the associated risk factors at a tertiary dermatology center: a case-control study

Laser hair removal (LHR) has been established as a safe and efficient method for eliminating unwanted hair. This study aimed to investigate the frequency of LHR complications and assess the contributing factors. During one year, 16,900 patients undergoing LHR therapy were evaluated for complications. For each case, two external controls were selected (matched based on age, sex, Fitzpatrick skin type (FST) III-IV, and the treated anatomical region). To assess the impact of anatomical region on complication occurrence, each patient was used as their internal control if another area was treated during the same session. GEE analysis was used for statistical analysis.

The incidence of LHR complications was calculated to be 0.69%. The most common complications were petechia, purpura, and ecchymosis (31.66%) followed by pigmentation changes (20.0%). LHR complications were most commonly observed in the lower limbs (32.0%), face and neck (23.3%), and genitalia and thighs (22.3%), respectively. Possible risk factors were younger age (OR = 0.74, P-value ≤ 0.001), operating LHR in the head and neck (OR = 5.8, P-value = 0.022), utilization of the alexandrite laser (OR = 2.32, P-value = 0.011), and fluence in the Alexandrite laser (OR = 3.47, P-value = 0.003).

Overall, the results of this study indicate that LHR is generally a safe method for removing unwanted hair. However, factors such as younger age, treatment of the facial area, and use of the alexandrite laser especially with higher fluence levels in patients with FST III-IV were identified as potential risk factors.