Hyperpigmentation and Hypopigmentation
There was a progressive improvement in baseline hyperpigmentation severity in participants treated with tretinoin lotion 0.05%; mean scores reduced from 0.8 at baseline to 0.6 by week 12 (Figure 3), with a similar improvement in both sexes (Figure 4). Moderate to severe hyperpigmentation was reported in 24 (17.3%) participants by week 12 compared to 41 (26.4%) at baseline; the majority (n=21) were female at week 12. Moderate to severe hyperpigmentation was reported in 24 (19.7%) participants treated with vehicle at week 12.
Figure 3. Postinflammatory hyperpigmentation and hypopigmentation in black patients treated with tretinoin lotion 0.05% or vehicle from baseline to week 12 (safety population; pooled data; N=291). Mean scores ranged from 0 to 3 (0=none; 1=mild).
Figure 4. A and B, Postinflammatory hyperpigmentation severity at baseline and week 12 by sex. Severity was determined using 4-point scale (0=none; 3=severe)(safety population; male and female subgroups; N=291).
Hypopigmentation at baseline was rare and mild, and again most common in female patients. There was no increase in hypopigmentation over the course of the study.
COMMENT
Topical retinoids (eg, tretinoin, adapalene, tazarotene) are recommended as the cornerstone of topical acne treatment, with safety and efficacy well documented in large pivotal trials.14 However, data in black patients are lacking. Acne is the most common dermatologic condition in these patients, and yet investigation into this important population is limited to small study populations or subgroup analyses.
Tretinoin lotion 0.05% is a novel topical treatment for moderate to severe acne that leverages polymeric emulsion technology. The development rationale was to provide a tretinoin formulation with improved efficacy and tolerability, features that could be especially suited to black patients with acne.
In our post hoc analysis of black patients with acne, tretinoin lotion 0.05% generally was considered safe and well tolerated. The most commonly reported treatment-related AEs were of low incidence and included application-site reactions and skin-related events attributed to the known properties of tretinoin. Most noteworthy was the extremely low irritation potential of this novel tretinoin formulation. Treatment-related AEs generally were mild, and interestingly, the majority occurred in female patients. The incidence of the most common treatment-related AEs—application-site dryness (2.6%) and application-site pain (2.6%)—was lower than that reported in the white populations in the 2 studies (3.8% and 3.4%, respectively).(unpublished data, Ortho Dermatologics), though the differences were not significant (P=.625 and P=.799).
Approximately one-quarter of participants had mild to moderate erythema, scaling, itching, and stinging at baseline. All of these cutaneous symptoms improved with treatment. There were slight transient increases in scaling and stinging at week 4, with stinging more noticeable in the female population. There were no noticeable changes in mild to moderate burning during the study.
Postinflammatory hyperpigmentation is an important consideration in black patients with acne. It can arise from either acne-induced inflammation or injury. It can be of greater concern to the patient than the acne itself and often is the main reason black patients seek a dermatologist consultation. In a survey of adult female acne, nonwhite women experienced substantially more PIH than white women. In addition, clearance of PIH was most important for these nonwhite women (42% vs 8% for white women), whereas lesion clearance was the most important aspect for white women (58% vs 32% for nonwhite women).15 Erring on the side of increased tolerability is appropriate in black patients with acne, given that any irritant reactions can lead to pigmentary alterations—hyperpigmentation or hypopigmentation—that can cause considerable patient anxiety. The psychologic impact of PIH can be devastating, and an ideal acne treatment in these patients would be one that is effective against both PIH and acne. Tretinoin cream 0.1% monotherapy has been shown to be effective in reducing PIH.16 Postinflammatory hyperpigmentation lesions and normal skin were assessed by clinical and colorimetric evaluations and by analysis of biopsy specimens. Although facial PIH lesions in the 24 tretinoin-treated patients were significantly lighter after 40 weeks of treatment compared to vehicle in this study (P<.001), overall improvement was first noted after 4 weeks (P=.009). Normal skin also was minimally lightened by tretinoin; however, exuberant local skin reactions, including peeling, developed in 50% of patients. Mild to moderate PIH was present in the majority of tretinoin-treated patients at baseline in our post hoc analysis, severe in 3.2% of cases, and both more common and severe in females. Mean scores reduced over the 12-week study period, from 0.6 to 0.4 in male patients and 0.9 to 0.7 in female patients. Hypopigmentation was rare and mild at baseline and did not increase over the course of the study. A pilot study with a cream formulation of tazarotene in patients with acne from darker racial groups showed the retinoid to be effective in treating PIH following 18 weeks of once-daily application.17 Further longer-term studies on treating PIH with tretinoin lotion 0.05% are warranted given its tolerability profile.
CONCLUSION
This novel tretinoin lotion 0.05% formulation is a safe and well-tolerated topical treatment for moderate to severe comedonal and inflammatory acne in black patients. Tretinoin lotion 0.05% does not appear to induce PIH and may afford an effective, well-tolerated, dual-treatment option.
Acknowledgments
We thank Brian Bulley, MSc (Konic Limited, United Kingdom), for medical writing support. Ortho Dermatologics funded Konic’s activities pertaining to this manuscript.