Practical management of acne-induced pigmentation: a systematic review

Abstract Background Acne-induced pigmentation (which includes postinflammatory hyperpigmentation) is a common sequela of acne vulgaris, particularly in patients with skin of colour. Despite its psychosocial burden, practical guidance on treatment selection remains limited. Objectives To systematically review the evidence for acne-induced pigmentation treatments and provide a clinically practical summary of the available therapeutic options. Methods A systematic review was conducted in accordance with PRISMA guidelines and registered on PROSPERO (CRD420251041782). MEDLINE and Embase were searched for randomized controlled trials, nonrandomized interventional studies, cohort studies and case series of ≥ 3 patients evaluating topical, oral, procedural, mechanical or combination therapies for acne-induced pigmentation published between 1 January 1999 and 31 July 2025 and written in English. Studies were grouped by intervention class and synthesized descriptively in line with Synthesis Without Meta-analysis (SWiM) guidance due to heterogeneity. Treatment response was categorized as a complete response, a partial response, poor-to-none response or worsening. Risk of bias was assessed using RoB 2 for randomized trials, ROBINS-I for nonrandomized studies and a quality checklist for case series. Results Fifty papers, comprising 51 studies, 69 interventions and 1868 patients, were included. Treatments with anti-inflammatory and pigment-modulatory effects, particularly topical retinoids and azelaic acid, were associated with a partial improvement in most included studies. Pigment-modulating agents, including 2-mercaptonicotinoyl glycine-, thiamidol-, cysteamine-, tranexamic acid- and hydroquinone-containing formulations, also demonstrated a partial response in several studies. Chemical peels and selected energy-based devices showed potential benefit, although the outcomes were variable and treatment-induced pigmentation remains an important consideration in darker skin phototypes. Adverse events were generally mild and transient, but reporting was inconsistent. Conclusions Acne-induced pigmentation should be managed as part of routine acne care rather than as a separate cosmetic concern. Current evidence supports prioritizing treatments that address both active acne and pigmentation, with adjunctive pigment-modulating or procedural therapies considered where pigmentation persists. However, the evidence base is limited by heterogeneity, small sample sizes, inconsistent outcome reporting and limited phototype-specific data. Standardized outcome measures and diverse, adequately powered comparative studies are needed to guide evidence-based treatment algorithms.