Clinical Evaluation of a 4% Hydroquinone + 1% Retinol Treatment Regimen for Improving Melasma and Photodamage in Fitzpatrick Skin Types III-VI

It is well known that the combined use of HQ and tretinoin improves both facial photodamage and melasma. Clinically, HQ therapy combined with retinoids such as tretinoin and/or corticosteroids has been found to be more effective in treating melasma than HQ monotherapy.^28-31 In addition, a combination of 4% HQ and 0.3% retinol cream was shown to be more effective than tretinoin 0.05% emollient cream in improving collective signs of photodamage in terms of dyspigmentation, fine wrinkles, and tactile roughness in 16 weeks.³²An easy-to-follow skin care system is available that incorporates a 4% formulation of HQ into a comprehensive skin care regimen providing cleansing, toning, exfoliation, and photoprotection. The objectives of our study were to evaluate treating epidermal melasma and photodamage with this skin care system in conjunction with retinol 1.0% cream for up to 24 weeks.

Single-center, investigator-blinded study. The IntegReview Institutional Review Board (IRB) in Austin TX approved the protocol, and the study was conducted according to the principles of the 2004 version of the Declaration of Helsinki. All patients signed informed consent.

Patients were eligible for study enrollment if they were healthy females aged 35 to 65 years with mild-to-moderate epidermal melasma (score of 2-5 on the Investigator Melasma Disease Severity Assessment), mild-to-marked melasma pigmentation (score of 1-7 on the Investigator Pigmentation Intensity Assessment), mild-to-moderate facial photodamage (score of 2-5 on the overall Facial Photodamage Scale), and a Fitzpatrick skin type of III to VI. Their cutaneous melanosis was required to have remained stable for the last three months.

Patients were treated with the 4% HQ skin care system (Obagi Nu-Derm®, Obagi Medical Products Inc., Irvine, CA) and 1.0% retinol and moisturizer for 24 weeks. The hydroquinone skin care system involved applying the following proprietary products: foaming gel cleanser (twice daily), toner (twice daily), 4% hydroquinone (twice daily), exfoliant containing alpha hydroxy acids (each morning), and sunscreen (SPF 50) containing micronized zinc oxide and octinoxate (each morning). Retinol 1.0% cream was applied each evening mixed 1:1 with 4% hydroquinone. Subjects performed the first test material application under supervision in the clinic.

Investigators evaluated melasma disease severity, melasma pigmentation intensity, melasma improvement assessment, photodamage improvement and local cutaneous tolerability (erythema, dryness, peeling) based on the criteria in Table 1-3. Patients evaluated any burning or stinging (Table 3), and completed questionnaires regarding their skin condition, regimen performance, product aesthetics and tolerance.In addition, overall melasma severity was assessed using the Melasma Area Severity Index (MASI).24 The melasma severity in each of the four facial regions (forehead [F], right malar region [MR], left malar region [ML], and chin [C]) was assessed based on three variables: percentage of the total area involved (A), pigment intensity (PI), and homogeneity (H), see Table 4, and MASI calculated using the following equation:MASI = 0.3 (PI_F + H_F) AF + 0.3 (PI_MR + H_MR) A_MR +0.3 (PI_ML+ H_ML) A_ML + 0.1 (PI_C + H_C) A_CValues 0.3, 0.3, 0.3, and 0.1 before each bracket represent the respective percentages of the total facial area. The maximum MASI score is 48.