Raphael Warren

Age, sunlight, and facial skin: A histologic and quantitative study

Quantitative methods were developed to assess the interrelation between age and sunlight on the facial skin of healthy women living in the same sunny area. The women were grouped into the following categories: young versus old and low versus high solar exposure. The features evaluated were perceived age, amount of facial wrinkling, skin color, and skin elasticity. A punch biopsy specimen of cheek skin was obtained and prepared histologically for evaluation of solar elastosis. The histologic examination was complemented by quantification of collagen and elastin by computer-assessed image analysis. Perceived age was estimated by untrained women viewing high quality photographs. As expected, those with greater sun exposure looked older and had more wrinkles, more severe elastosis, increased elastin, and decreased collagen.

The influence of hard water (calcium) and surfactants on irritant contact dermatitis

Although the induction of irritant contact dermatitis has been extensively studied for surfactants, the role of the environmental factor water hardness (i.e., calcium content) on the induction process has not received attention. Our objective was 10 investigate differences in surfactant‐induced irritant skin reactions from cumulative exposure to 3 different personal cleansing agents and determine whether the irritation potential can be affected by the hardness of the water. 2 commonly used exaggerated washing procedures were variously employed lo evaluate representative sodium‐soap, triethanolamine‐soap, or synthetic detergent cleansers under conditions where the water hardness varied from 0‐grain to 11‐grain (gr). Subjects were clinically evaluated for skin dryness, skin redness, and instrumentally for hydration. Soap binding to skin was quantified using Fourier transform infrared reflectance spectroscopy. Using the more mild wash procedure, skin sites treated under conditions of hard. 11 gr water, were significantly drier, had more erythema, and were less hydrated than corresponding sites treated with deionized 0 gr water. All 3 surfactant cleansers behaved similarly. We also found the hardness of the rinse water to be the more significant factor, versus that of the wash water. Effect of water hardness on soap binding to skin revealed a similar outcome. Under a more exaggerated wash condition the relationship between water hardness and irritation broke down.

SENSITIVITY OF MOUSE SKH:HR‐2 TO ULTRAVIOLET LIGHT: MOUSE PIGMENTATION MODEL

Abstract— The mouse Skh:HR‐2 has been reported to be sensitized to ultraviolet light and become pigmented. Using three independent parameters associated with pigmentation. we have examined the ability of the mouse to become pigmented. The methods utilized were spectroscopic (skin color). histological (melanocyte density and epidermal thickness), and biochemical (tyrosinase activity). Following a two‐week ultraviolet exposure, the mice were pigmented with the degree of pigment change related to the ultraviolet dose administered. Perturbations in skin color, epidermal thickness, melanocyte density, and tyrosinase activity were recorded. Mice were also examincd for their response to tyrosinc applied topically following each ultraviolet exposure. With the exccption of epidermal thickness. all the pigmentation parameters were accentuated when compared to results from ultraviolet exposure alone.

The Vulva is Relatively Insensitive to Menses-Induced Irritation

ABSTRACT Skin patch testing of menses and venous blood on the vulva (labia majora) and the upper arm was performed to assess the potential contribution of these biological fluids to vulvar irritation during menstruation. After 24 and 48 hours of occlusive exposure, the skin of the labia majora was relatively unaffected by these fluids compared to the skin of the upper arm: no significant irritation was observed on the labia at either exposure time, but discernible irritation was elicited on the upper arm after 48 hours of exposure. Pre-treatment of the upper arm with a petrolatum-based emollient attenuated the upper arm response. Semi-occlusive conditions also reduced the degree of upper-arm irritation elicited test materials and an irritant control, sodium lauryl sulfate. The relative insensitivity of the vulva to irritation by menses or blood was not predictable a priori because some irritants elicit heightened responses on the vulva relative to the arm (3). These results suggest that the vulva (labia majora) may be adapted to be less sensitive to menses-induced skin irritation than other anatomical sites.

Emollients on the genital area.

Emollients are known to lubricate, moisturize and soothe the skin. Prior to their incorporation into feminine hygiene pads, thorough premarket toxicological testing is conducted to evaluate their safety and effectiveness via in-use clinical settings. Product testing has been conducted on various body sites proven previously to be valid and reliable, such as the arm and popliteal fossa and, more recently, the genital area. Several clinical studies have confirmed the safety and efficacy of emollient-containing feminine hygiene products, which have also been shown to provide dermatological benefits in the genital area.