Dermoscopic classification of melasma: Concordance study and correlation with the melanophages count.

BACKGROUND: Melasma is a common hypermelanosis characterized by symmetrical brownish macules, especially on the face. Histologic analysis demonstrates increased epidermal and dermal melanin. Dermoscopy is useful to estimate the depth of the melanin and may help in the diagnosis and classification of melasma, with therapeutic importance. OBJECTIVES: To evaluate the diagnostic concordance of dermoscopic classification of epidermal or mixed subtypes of melasma and the correlation between dermoscopic and histopathological findings. METHODS: Twenty-eight women with facial melasma, phototypes III to V, ages between 30 and 61 years were selected. Based on the evaluation of clinical and dermoscopic images, two independent observers classified melasma into epidermal or mixed subtypes. The intra and interobserver concordances were calculated. Histopathological analysis of epidermal melanin extension and maximum number of melanophages per high-power field (400×; HPF) have been assessed. Association between the melanophages count and the dermoscopic classification was evaluated. RESULTS: Intraobserver agreement was 82.1%, and between observers, from 78.6% to 89.3%, according to the Kappa index. Histopathology revealed increased intraepidermal melanin and the presence of dermal melanophages in all the samples. Ten or more melanophages/HPF was significantly associated with mixed melasma. CONCLUSIONS: Moderate to substantial concordance in the dermoscopic classification of melasma was found, and the correlation between this classification and the dermal melanophages count have been suggested. Intradermal component of every case of melasma should be considered for therapeutic and prognostic purposes.

The Shampoo pH can Affect the Hair: Myth or Reality?

AIM: Dermatologists most frequently prescribe shampoos for the treatment of hair shed and scalp disorders. Prescription of hair care products is often focused on improving scalp hair density, whereas the over-the-counter products focus on hair damage prevention. Little is taught in medical schools about the hair cosmetics, so that the prescriptions are based only on the treatment of the scalp and usually disregards the hair fiber health. MATERIALS AND METHODS: In this work, we review the current literature about the mode of action of a low-pH shampoo regarding the hair shaft's health and analyze the pH of 123 shampoos of international brands. RESULTS: All shampoo pH values ranged from 3.5 to 9.0. 38.21% of all 123 shampoos presented a pH ≤ 5.5 (IC: 29.9-47%) and 61.78% presented a pH > 5.5. 26 anti-dandruff shampoos were analyzed. About 19.23% presented pH ≤ 5.5.(IC: 7.4-37.6%). 80.77% of all anti-dandruffs shampoos presented a pH > 5.5. The dermatological shampoo group (n = 19) presented 42.10% with pH ≤ 5.5 (IC: 21.8-64.6%), and 57.90% with pH > 5.5. Among the commercial (popular) products (n = 96), 34.37% presented pH ≤ 5.5 (IC: 25.4-44.3%) and 65.62% presented pH > 5.5. 15 professional products (used in hair salons) were analyzed, of which 75% had a pH ≤ 5.5 (IC: 18-65, 4%), and 25% had a pH > 5.5. 100% of the children's shampoos presented a pH > 5.5. CONCLUSIONS: Alkaline pH may increase the negative electrical charge of the hair fiber surface and, therefore, increase friction between the fibers. This may lead to cuticle damage and fiber breakage. It is a reality and not a myth that lower pH of shampoos may cause less frizzing for generating less negative static electricity on the fiber surface. Interestingly, only 38% of the popular brand shampoos against 75% of the salons shampoos presented a pH ≤ 5.0. Pediatric shampoos had the pH of 7.0 because of the "no-tear" concept. There is no standardized value for the final pH. The authors believe that it is important to reveal the pH value on the shampoo label, but studies are needed to establish the best pH range for both the scalp and the hair fiber's health.