short-term measure. However, overly aggressive intralesional injections using higher concentrations can lead to corticosteroid-induced hypopigmentation in darker skinned patients.
Avoiding iatrogenic PIH from medication-induced irritation is essential. Special considerations need to be made regarding specific therapeutic agents, concentrations, and vehicles in order to select a regimen that is well tolerated by a given patient. While all Food and Drug Administration (FDA)-approved topical acne treatments can safely be used in patients with skin of color, individual variations in sensitivity exist and should be accounted for when selecting a regimen for any given patient. Erring on the side of increased tolerability is a prudent approach for patients with skin of color, given that any irritant reactions can lead to pigmentary alterations (hyper- or hypo-pigmentation). While such treatment-related dyschromias are generally self-limited, they tend to cause considerable patient anxiety and loss of confidence in the prescriber on the part of the patient.
Tolerability considerations are especially important when selecting topical retinoids. While all FDA-approved topical retinoids can safely be used in patients with skin of color, adapalene 0.1% is associated with the least irritation potential23-26 and has been studied in numerous populations with skin of color – including studies conducted in South Africa,27,28 Japan,29 China,25 Singapore,26 and Mexico.30 Tretinoin is best tolerated in a branded microsphere formulation or an aqueous gel. However, when generic tretinoin formulations are used, it is advisable to initiate treatment with the lowest concentration (0.025%), titrating up to higher concentrations in the appropriate patient.10 Tazoratene is best tolerated as a cream; initiating this at the lowest concentration (0.05%) and titrating to higher concentrations and/or gel formulations in the appropriate patient is the preferred approach.10
When BPOs are used on the face, vehicle and concentration considerations are important with respect to maximizing tolerability. When treating facial acne, 2.5%- 5.5% BPO formulations in aqueous gels, microsphere cream, or emollient foam are generally well tolerated and strongly preferred over products in ethanolic gels or those with higher concentrations. However, concentrations up to 10% found in BPO cleansers or a short-contact emollient foam preparation are generally well tolerated on the trunk.
Several meta-analysis studies investigating the comparative safety and efficacy of topical acne formulations between higher and lower Fitzpatrick skin types, as well as investigations into specific racial/ethnic groups, have recently been published. Most recently, a subgroup analysis evaluating the efficacy and safety of adapalene 0.1%/BPO 2.5% gel in 238 black subjects was published. Adapalene/BPO gel was well tolerated in this cohort, and no cases of treatment related PIH were observed.31 A previous study demonstrated comparable tolerability of adapalene/BPO gel in subjects with Fitzpatrick skin types I to III and IV to VI.32 A similar study involving clindamycin phosphate 1.2%/BP gel found no differences in cutaneous irritation in Fitzpatrick skin types I to III vs IV to VI.33 This formulation was also investigated in Hispanic subjects in a post-hoc analysis, in which Hispanic patients were not found to be more sensitive to treatment-related cutaneous irritation. A small pilot study found clindamycin phosphate 1.2% and tretinoin 0.025% gel to be well tolerated in 33 patients with Fitzpatrick skin types IV to VI.34 In a subset analysis of a community-based trial of combination therapy with clindamycin 1%/BPO 5% gel and topical tretinoin microsphere or adapalene gel 0.1%, treatment was well tolerated with a trend toward better resolution of hyperpigmentation with clindamycin/BPO gel in combination with tretinoin microspere gel 0.04%.35 In a comparative meta-analysis, adapalene 0.1% in black patients vs white patients was associated with a low incidence of irritation (erythema, scaling, and dryness).
To maximize tolerability, patients should be counseled to avoid harsh scrubs, toners, and exfoliating cleansing routines that can increase the risk of irritation from prescription therapies.36 Initiating therapy with every other night dosing of retinoids and applying a non-comedogenic moisturizer immediately after topical prescriptions are useful strategies for maximizing tolerability and minimizing dryness/ peeling. In patients with extremely dry, sensitive skin, applying a moisturizer prior to the retinoid can be helpful.37
- Designing a treatment regimen that helps to reduce PIH is a strategy that increases patient satisfaction. This involves selecting products that have dual efficacy–treating both acne and hyperpigmentation (such as retinoids and azelaic acid), as well as adjunctive therapies that specifically target PIH (including hydroquinone and chemical peels).9,38 The topical retinoids are particularly useful in the management of both acne and PIH in skin of color. Tretinoin,39 adapalene,27,28 and tazarotene40 have all been shown to reduce PIH in studies involving patients with skin of color. A fixed dose of triple combination therapy has also been shown to improve PIH. (Galderma data on file, study report HD TL 043 A-B). To align the dermatologist’s treatment endpoint with patient expectations, follow-up evaluations should be continued until the clearance of both active acne lesions and PIH. Thus, the time course to achieving a treatment success is on average longer in a patient with skin of color, typically spanning 6 months or more.