Evaluation of Mild Skin Cleansers

The science behind skin care: Cleansers

Two of the most important skin care categories with profound dermatologic implications are cleansers and moisturizers. Cleansers are composed of alkaline soaps or the less barrier-damaging synthetic detergents, known as syndets. The lower skin irritation and dryness found with syndets are related to their reduced tendency to cause protein denaturation due to the charge density of protein-bound micelle-like surfactant aggregates. Many cleansing formulations are available for purchase to meet hygiene needs varying by sex, age, ethnicity, occupation, environment, personal preferences, and the presence or absence of skin disease. This discussion covers the science of skin cleansing.

Moist exposed therapy: an effective and valid alternative to occlusive dressings for postlaser resurfacing wound care

BACKGROUND

Laser resurfacing has now become an accepted and important component of facial rejuvenation. With the introduction of computerized scanning systems, the actual laser resurfacing technique has been greatly simplified; however, the final outcome still depends to a large extent on the efficiency of the postlaser wound care in promoting wound healing and preventing early and late complications. It has been repeatedly confirmed that a moist environment is the single most important external factor affecting the rate of re-epithelialization. Occlusive moisture-retentive dressings, however, are difficult to apply and maintain in position and may as well be complicated by serious infections.

OBJECTIVE

Moist exposed burn ointment has been shown to maintain adequate moisture for optimal healing by frequent ointment application without the need for a secondary overlying dressing. It would be ideal for postoperative laser care.

METHODS

Twenty-eight consecutive patients treated with coherent ultrapulse CO2 laser in Toulouse, France, were included in the trial. Moisture-retentive ointment was applied over the treated areas every 4 to 6 hours. Healing was assessed clinically and with repeated transepidermal water loss measurements. Swab cultures were taken, and pain was evaluated with a visual analog scale. Colorimetric analysis of pictures taken was statistically compared with picture analysis of 20 patients treated earlier with an occlusive dressing.

RESULTS

Uneventful timely healing occurred in all patients with minimal pain and discomfort. Healing with moist exposed therapy resulted in faster recovery of cutaneous erythema, as evidenced by colorometry.

CONCLUSION

Moist exposed burn ointment application can be safely considered a good and valid alternative to occlusive dressings for postoperative laser care.

Scar quality and physiologic barrier function restoration after moist and moist-exposed dressings of partial-thickness wounds

BACKGROUND

There is growing evidence of improved healing of full- and partial-thickness cutaneous wounds in wet and moist environments. Retention of biologic fluids over the wound prevents desiccation of denuded dermis or deeper tissues and allows faster and unimpeded migration of keratinocytes over the wound surface. It allows also the naturally occurring cytokines and growth factors to exert their beneficial effect on wound contracture and re-epithelialization. Despite all of these documented benefits, applying the moist healing principles to large surface areas, in particular to large burns, is hindered by the major technical handicap of creating and maintaining a sealed moist environment over these areas.

METHODS

From January to September 2001, healing of partial-thickness skin graft donor sites was studied in a prospective comparative study of two types of moist dressings, Tegaderm (3M Health Care, St. Paul, MN), a semipermeable membrane occlusive dressing, and moist exposed burn ointment (MEBO) (Julphar; Gulf Pharmaceutical Industries, United Arab of Emirates), an ointment that can provide a moist environment without the need of an overlying occlusive dressing. Healing was assessed both clinically and with serial measurements of transepidermal water loss (TEWL) and moisture. Following healing, scar quality was evaluated by two members of the team separately using a visual analog scale. Results were statistically analyzed.

RESULTS

Faster healing was observed clinically with MEBO application. Physiologic healing as determined by TEWL measurements occurred at an extremely significant earlier stage for MEBO, and this was associated with better scar quality, demonstrating a positive relationship between function and cosmetic appearance. Moreover, the ointment is definitely easier to apply than the occlusive self-adhesive membrane, which requires some degree of dexterity and expertise.

CONCLUSION

MEBO application is an effective and valid alternative to conventional occlusive dressings. Moreover, the observed improved anatomic and physiologic healing indicates that MEBO may have a positive effect on healing more that the mere fact of passive moisture retention.

Correlation between pH and irritant effect of cleansers marketed for dry skin

BACKGROUND

Although it is important that dermatologists and the general population know the irritation potential of products marketed for dry skin used for body cleansing, this information is not usually available.

OBJECTIVE

To assess the irritative effect of different soaps and liquid cleansers recommended for sensitive skin. To study the correlation of the irritation effect of each substance with its pH and with the presence or absence of syndet in the product.

METHODS

Seventeen products marketed for dry skin and 12 common soaps used by the general population were studied. Fresh soap emulsions (8%) were applied to the volar side of the right forearm of 30 individuals with sensitive skin for 5 consecutive days using aluminum chambers. The appearance of irritation (erythema, scaling and fissures) was recorded, scored, and expressed in an Irritation index (IrIn). The pH of each solution was measured.

RESULTS

Products with a low IrIn were White Dove (Dove, Lever Pond's, Toronto, Ontario, Canada), Dove Baby, Cetaphil (bar) (Cetaphil, Gulderma Lab., Forth Worth, TX, USA), Dove liquid cleanser for hands, Dove pink, and Aderma (Adenma, Pierre Fabre, Dermo-Cosmetique, Boulagne, France). Most corresponded to syndet products. Among the most used brand-name soap, Camay Classic (Camay, Procter & Gamble de Mexico, México, U.F.) had the lowest IrIn. Dove Baby was the only product with a neutral pH. A significant correlation between pH and the IrIn of cleansers was found (P < 0.006).

CONCLUSIONS

Most products recommended for sensitive skin have a considerable irritation effect, which is related to the pH of the product. Better regulation of advertisement specifications including the pH level and type of cleanser contained is necessary for the majority of soaps and cleansers.

Effects of various grit-containing cleansers on skin barrier function

Products intended for individuals in contact with strongly adhering dirt often contain grit. Various clinical test methods have been developed for evaluating the potential of personal washing products to induce skin irritation. In the present study, differences in the irritant effects of washing products containing naturally-derived grit and synthetic grit were investigated in a forearm wash test. The forearms of 16 test subjects were washed in a total of 18 treatments (4 per day for 4 days, with 2 treatments on the 5th day). Treatment consisted of continuous washing for 2 min by a technician, who gently slid his fingertips with the lather up and down the forearm. Non-invasive instrumental measurements of skin barrier function were performed. Repetitive washing for 1 week lead to increased TEWL values, skin redness and decreased stratum corneum hydration. Results indicate differences in irritancy potential due to different types of grit, their surface and concentration. It is concluded that the repeated wash test seems to be adequate for rating personal washing products that contain grit.

Intra-and inter-individual variations in transepidermal water loss on the face: facial locations for bioengineering studies

The volar forearm is the favored location for bioengineering studies. However, transepidermal water loss (TEWL), which is an important indicator of the function of the epidermal barrier, shows regional variations, and for the evaluation of cosmetic formulations, facial skin would be more suitable. In this study, we have compared 10 facial locations with 1 test site on the volar forearm for absolute TEWL values, reproducibility, and correlation. Measurements were performed over 3 consecutive days. The TEWL values of the facial test sites were higher compared to forearm values and did not correlate with the forearm. On the face, there was a good correlation between the values of the right compared to the left side of the face. The sites superior to the nervus supraorbitalis, the medial borders of the musculus masseter, and the center of the chin proved to be locations with relatively stable TEWL values. There was a greater variability at the center of the forehead and at the center of the cheeks. It is recommended that TEWL measurements on facial locations with stable TEWL values are used for the evaluation of cosmetic formulations.

Cosmetics, skin care products, and the dermatologic surgeon. Postsurgical selection of cleansing products

Postsurgical care is almost as important as the skill of the dermatologic surgeon in ensuring the patient a good result. Scientifically based cleansing product selection and careful patient cleansing instructions are necessary to optimize healing while meeting patient hygiene needs.

Irritant effects of a detergent in wash, chamber and repeated open application tests

Development of irritant contact reactions in a wash test, in a repeated open application test (ROAT) and in chamber tests were compared with each other in 14 atopic and 14 non-atopic Caucasian medical students. In the wash test, the students washed their upper arm skin with 10% dishwashing liquid for 1 min 2 x a day for 1 week. In the ROAT, they applied the same detergent solution to 1 antecubital fossa 2 x daily for 1 week. Chamber tests were performed with the same detergent using 8 mm, 12 mm and 18 mm Finn Chambers applied to the upper back skin for 48 h. Additional 4 h and 24 h occlusion times were used with the 12 mm Finn Chambers. Test results were evaluated on days 0, 2, 4 and 7 by eye and by using an Evaporimeter EP1 for transepidermal water loss and a Minolta Chroma Meter CR-200 for skin colour. No statistically significant differences between atopics and non-atopics were found in any of the tests. The results of the tests did not correlate with each other, with the exception of the 12 mm/48 h chamber test and the wash test in atopics (R = 0.61, p = 0.02). It seems that other individual factors in addition to atopy influence the development of irritant contact dermatitis. The results of the chamber test and ROAT predicted poorly the result of the wash test.

Irritant effects of a detergent in wash and chamber tests

Irritant properties of detergents can be tested by using patch and chamber tests and various kinds of use tests. The aim of the present study was to compare the results of use and 12 mm Finn Chamber tests. Study subjects (10 atopic and 11 non-atopic medical students) washed the outer aspect of 1 upper arm with liquid detergent for 1 minute 2 x daily for 1 week. 48-h chamber test with 5 concentrations of the same detergent in water were concurrently applied to upper back skin. Transepidermal water loss (TEWL), electrical capacitance and skin blood flow were measured to quantify reactions on days 0, 2, 5 and 7. Irritant contact dermatitis developed equally in atopics and non-atopics in the wash test, whereas in the chamber test with a 10% aq. solution of the detergent, increase in TEWL was significantly higher in atopics than in non-atopics. The chamber test results thus predicted poorly the result of the wash test. This might indicate that the wash test and the chamber test measure different aspects of skin barrier function.