Optimizing acne and hyperpigmentation treatment in patients with skin of color: A clinical experience on triple acid chemical peels

INTRODUCTION

The prevalence of acne vulgaris spans across various ethnic groups, affecting up to 90% of young people during adolescence and often continuing into their adult years. This skin condition, which manifests as either non-inflammatory lesions such as comedones or inflammatory ones such as nodules and cysts, can have a profound impact on one’s psychological well-being, contributing to anxiety, depression, and even severe distress.^[1,2] To manage acne, a range of treatments are employed, from oral medications and topical solutions to more physical interventions such as laser and chemical peels. Among these, chemical peels serve not only to treat acne but also play a role in cosmetic improvement, targeting issues such as photoaging and hyperpigmentation.^[1] These peels, which vary in depth from superficial to deep, work by controlled damage to the skin, leading to the regeneration of skin layers. The depth of the peel is controlled by factors including the acid concentration and the duration of its application, with superficial peels typically addressing active acne and deeper peels aimed at correcting scarring.^[1,3]

MATERIALS AND METHODS

This study was conducted at the dermatology clinic of the General Soedirman National Defense Central Hospital, Jakarta, Indonesia. A cohort of ten patients aged 17–35 years presented with mild-to-moderate acne accompanied by post-acne hyperpigmentation. The inclusion criteria were patients with acne of mild-to-moderate severity; those with active facial infections, active inflammatory dermatitis, pregnancy, or lactation were excluded from the study. Each patient underwent a series of three chemical peeling treatments at bi-weekly intervals. The chemical peel solution consisted of a combination of 20% salicylic acid, 5% citric acid, and 5% mandelic acid applied in three layers.

Before the application of the peel, all patients’ face was cleansed using a foamer containing 15% glycolic acid. The peeling solution was then applied in three layers, with a 1-min pause between each layer. The final layer was left on the skin for 4–5 min before rinsing with water and patting the face dry. Post-peel care involved the application of a post-peel cream containing sun protection factor (SPF) 50, glycoprotein, Vitamin C and E, and anti-inflammatory agents known as K-complex, a proprietary formula from Dermaceutic Lab®, France.

Home care instructions post-chemical peels included the use of sunscreen with an SPF of 30 during daytime and moisturizer at night containing hyaluronic acid, aloe vera, jojoba oil, Vitamin E, and shea butter. Patients were advised against the use of topical or systemic antibiotics for 1 month before and during the peel treatments. Written informed consent was obtained from all participants for inclusion in this case series report, which also included consent for the use of photographic documentation for presentation in the report.

The severity of acne was measured using Michaelson’s acne severity score, which was assessed by counting the number of lesions on the face at baseline, at each visit, and 2 weeks post the final treatment session. Lesion types were assigned a score reflecting their severity (comedones = 0.5; papules = 1.0; pustules = 2.0; infiltrates = 3.0; and cysts = 4.0), and the total score was calculated by multiplying the number of each lesion type by its corresponding severity index. Clinical photographs and a skin analyzer (Janus®, PIE, South Korea) were utilized to demonstrate therapeutic effects. Esthetic improvement was evaluated using the subject global esthetic improvement scale (SGAIS), which employs a five-point scale ranging from 1 (exceptional improvement) to 5 (worsening of the condition).

RESULTS

In this study, ten patients underwent a series of chemical peeling procedures, each completing three treatment sessions at 2-week intervals. Remarkable clinical improvements were observed in all patients, as evidenced by the reduction in inflammatory lesions, the diminishing of post-acne hyperpigmentation and erythema. These improvements were visually apparent in clinical photographic documentation and skin analyzer results [Figure 1]. The study cohort had a mean age of 25.3 ± 5.7 years (range 17–35), consisting of seven females and three males. All patients had Fitzpatrick skin type IV.

The severity of acne was quantitatively assessed using Michaelson’s score at various stages: pre-treatment, after the second and third treatment sessions, and 2 weeks following the final session. Initially, the average score before treatment was 61.1, which significantly reduced to an average of 11.8 2 weeks after the last session [Figure 2]. Post-inflammatory hyperpigmentation (PIH) improvement was visually assessed through serial photographic comparison and confirmed by reduction in melanin index on the Janus® skin analyzer. Average melanin index scores declined 30–35% over the treatment period. The detailed progression of acne severity scores for each patient is presented in Table 1.

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Figure 1:

(a, b) baseline condition. (c, d) improvements after 4 weeks of triple-acid chemical peel treatment.

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Figure 2:

(a) baseline photograph of inflammatory acne. (b) improvement after 4 weeks of treatment.

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Patient satisfaction with the treatment was measured using the SGAIS. The SGAIS was used, where 1 = exceptional improvement, 2 = very improved, 3 = improved, 4 = no change, and 5 = worsened. All patients rated their esthetic outcome as Grade 2 or 3.

Two weeks post the final session, all patients reported satisfaction with the treatment outcomes based on this scale. Importantly, no adverse events such as dyspigmentation or scarring were reported by any of the patients, indicating a favorable safety profile for the chemical peeling procedure used in the treatment protocol.

DISCUSSION

The clinical trial conducted provides a compelling case for the synergistic effects of salicylic, citric, and mandelic acids in managing cutaneous manifestations of acne vulgaris and post acne hyperpigmentation, particularly within the unique context of Fitzpatrick skin phototypes IV and V. These findings are consistent with recent dermatological advancements that advocate for the tailored application of chemical exfoliants in managing hyperpigmentation and acne in darker skin tones, which are more susceptible to PIH.^[4]

The incorporation of salicylic acid, a beta-hydroxy acid, is particularly noteworthy given its lipophilicity, which confers an enhanced ability to penetrate sebaceous follicles, dissolving the inter-follicular lipid matrix and mitigating comedogenesis.^[5] The anti-inflammatory properties of salicylic acid, attributed to its inhibition of cyclooxygenase-2, also play a pivotal role in reducing the inflammatory component of acne lesions, which is often exacerbated in darker skin types.^[6]

Mandelic acid, an aromatic alpha-hydroxy acid (AHA), exhibits a larger molecular weight, reducing its cutaneous penetration and thereby attenuating the potential for erythema and desquamation, which can be particularly problematic in skin types prone to PIH.^[7] Moreover, its antibacterial and anti-inflammatory activities contribute to the holistic treatment of acne and reducing the risk of hyperpigmented areas, a duality of action that is valuable in treating the multifactorial nature of acne-related dyschromia.^[8] Citric acid, a type of AHA, is utilized in skincare for its exfoliative properties, which can aid in the reduction of hyperpigmentation, including that resulting from acne. AHAs like citric acid work by penetrating the stratum corneum, the outermost layer of the skin, and promoting desquamation. This process facilitates the removal of dead skin cells, leading to a smoother skin texture and an improvement in overall complexion. In addition, AHAs stimulate collagen synthesis in the dermis, enhancing skin elasticity and firmness, and attenuating fine lines and wrinkles. The effectiveness of citric acid and other AHAs in treating skin conditions such as hyperpigmentation, acne, and photoaging has been extensively studied, confirming their beneficial effects in improving skin texture and tone. However, research continues optimizing AHA formulations, including the appropriate concentration and pH for maximum efficacy while minimizing potential side effects like skin irritation.^[9] This aligns with emerging studies that underscore the potential of citric acid as an adjunctive agent in the treatment of hyperpigmentation disorders.^[10] The reduction in melanin index and visible lightening of hyperpigmented macules suggests that this triple acid formulation is not only effective for acne lesions but also contributes significantly to pigment clearance in darker skin types.

The absence of severe adverse events in this cohort is a testament to the safety profile of the utilized acids at the given concentrations. This is particularly significant given the vulnerability of Fitzpatrick skin types IV and V to PIH and scar or keloid formation post-procedure.^[11-13]

Nevertheless, the study is delimited by its limited sample size and the lack of a comparative arm employing monotherapy or differing concentrations of acids. Future research with a randomized controlled methodology and a larger sample size would provide more robust evidence. Moreover, longitudinal studies are imperative to assess the durability of clinical improvement and the recurrence rate of acne and hyperpigmentation.

CONCLUSION

The triple-acid chemical peel, which comprises salicylic acid, citric acid, and mandelic acid, as investigated in this study, shows considerable promise as a therapeutic approach for treating acne and hyperpigmentation in patients with Fitzpatrick skin types IV and V. This innovative treatment strategy has the potential to significantly enrich dermatological practices by providing a tailored, safe, and highly effective regimen. The unique combination of these three acids – salicylic acid, known for its profound impact on acne, citric acid offering antioxidant properties, and mandelic acid recognized for its gentler exfoliating effects – creates a comprehensive treatment solution. These findings suggest that incorporating this triple-acid formula into dermatological treatments could lead to improved outcomes for patients with skin of color, particularly those who have traditionally faced challenges in finding effective and safe treatment options for their skin concerns.