Post‐inflammatory hyperpigmentation: A systematic review of treatment outcomes

Post-inflammatory hyperpigmentation is a common consequence of inflammatory dermatoses. It is more common in patients with darker skin and has significant morbidity. This systematic review summarizes treatment outcomes for post-inflammatory hyperpigmentation to help physicians better predict clinical response and improve patient outcomes. Embase, MEDLINE, PubMed databases and clinicaltrials.gov were searched in accordance with PRISMA guidelines using a combination of relevant search terms. Title, abstract and full text screening were done in duplicate. Studies were included if they met our predetermined PICOS framework criteria. Results are presented in descriptive form. In total, 41 studies representing 877 patients were included. Complete response was achieved by laser and energy-based devices in 18.1% (n = 56/309) of patients, topicals in 5.4% (n = 20/369) and combination therapies in 2.4% (n = 4/166). Partial response was achieved by combination modalities in 84.9% (n = 141/166) of patients, topicals in 72.4% (n = 267/369), laser and energy-based devices in 61.2% (n = 189/309) and peels in 33.3% (n = 5/15). Poor to no response occurred with peels in 66.7% (n = 10/15) of patients, topicals in 22.2% (n = 82/369), laser and energy-based devices in 18.1% (n = 56/309) and combination modalities in 12.7% (n = 21/166). Additionally, in 2.6% (n = 8/309) of patients treated with laser and energy-based devices, post-inflammatory hyperpigmentation worsened. Adverse events were reported in 10 patients, all while using topical treatments. In conclusion, the current treatment approaches yielded unsatisfactory rates of complete response. However, combination therapies, laser and energy-based devices and topical therapies showed high rates of partial response. Of note, the majority of post-inflammatory hyperpigmentation cases included were associated with acne, and therefore, the findings and conclusions drawn may have limited applicability to other types of post-inflammatory hyperpigmentation.