The Evidence-Based Clinical Practice Guideline for neonatal skin care, including a Neonatal Skin Condition Scale (NSCS), has been validated by the Association of Women’s Health, Obstetric and Neonatal Nurses (AWHONN) and the National Association of Neonatal Nurses (NANN). Within the Guidelines, the use of emollients is recommended for infants less than 32 weeks during the first 2-4 weeks. For infants younger than 30 weeks, gestational age emollient use is recommended to reduce excessive transepidermal water loss (e-TEWL).
Over a period spanning three decades, the handling of neonates has radically changed and the new guidelines highlight this growth and development. However, this area of skin care has lagged behind. One concern that remains is the issue of the toxic effects of ingredients found in water-based products like preservatives and fragrances. While it is possible that these may be toxic, this article will present evidence that the current skin care products that contain petrolatum and lanolin may be more toxic and potentially harmful. Further, using a product that is not preserved, yet occlusive, may in fact allow for microorganisms in colony forming units to multiply, thereby yielding systemic implications. The purpose of this article is to further illuminate these issues and to allow for greater understanding and discussion.
Skin is the largest organ of the body and provides protection between the body and its environment. In term babies, while there may be issues related to skin breakdown and infection, the stratum corneum is fully developed and protects the newborn. In contrast, the skin and skin barrier of a preterm neonate is not fully developed.
The skin of a premature neonate accounts for approximately thirteen (13) percent of its body weight. This compares to three (3) percent of body weight for adult skin. The body weight to skin ratio is four (4) times greater in the neonate when compared to an adult. As related specifically to skin care, these characteristics in neonate skin call into account:
• Fluid imbalances
• Percutaneous absorption of toxins
• Tissue injury
The structure of adult skin is understood, while embryonic and neonate skin is not fully appreciated. Development of the skin within the uterus is complex and still under investigation. In utero, the skin undergoes two-dimensional growth to cover the surface area of the developing embryo and fetus. Premature neonate’s skin has not gone through full epidermal and dermal epidermal development.
In neonatal intensive care units (NICU) skin care product selection is carefully reviewed. With the risks outlined above, great care must be taken to ensure the wellbeing of the neonate within the first hours and days of life. Care of the skin is one of the most important areas of care for these at risk infants. Currently, NANN and AWHONN recommended a Aquaphor?, a petrolatum-based product as neonate skin care emollient.
In earlier work done at Stanford University, it was concluded that emollient cream moisturizer therapy of premature neonates decreases dermatitis without changing the microbiological flora. An emollient is an agent that softens or soothes skin. This definition is important because just as the standard-of-care has changed in NICUs over the past three decades, the selection of emollients has changed in the pharmaceutical industry.
High-tech silicone excipients have displaced petrolatum as companies have sought ways to improve treatment compliance traced to poor aesthetics associated with petrolatum-based formulations. Silicones are not new to the pharmaceutical industry. They are used in transdermal delivery systems, catheters and specialized medical devices, including pacemakers.
In a test to determine aesthetic benefits of silicone formulas over petrolatum-based formulas, 18 untrained volunteers were impaneled. They were asked to evaluate whether two products present any differences on individual sensory properties. The evaluation was conducted on the panelist’s forearms. Each panelist was asked to evaluate wetness, spreadability, speed of absorbance (not biologically, just feel), gloss, film residue, greasiness, silkiness and slip after perceived absorbance.
Figure I shows the silicone-containing formulation was perceived to be easier to spread and was clearly less tacky before and after absorption. A perceptible film was present on the skin for both formulations but the silicone-containing formulation was less greasy, silkier and more slippery (better lubrication) than petrolatum. The panelist’ perception of higher wetness for the silicone-containing formulation was attributed to its lower oiliness.
In a study conducted at a 48-bed NICU private hospital in Houston, Texas, to evaluate why the rate of systemic candidiasis (SC) per 1000 NICU patient-days increased from 5.1% in 1996 to17.4% in 1997 (a three-fold increase), it was determined that the increase in SC incidences was linked to the use of topical petrolatum ointment (TPO). In this well designed study, the investigators went on to hypothesize that TPO enhanced the adherence of C albicans to mucocutaneous surfaces. Also referenced in the study was a finding by Law S, et al, that unlike petrolatum, skin surface lipids inhibit adherence of candida albicans to stratum corneum.
By way of further examination, let’s more closely examine these two hypotheses. As observed in the Houston study, petrolatum enhanced adherence of C albicans to mucocutaneous surfaces. Petrolatum is known as an occlusive barrier. Occlusion is problematic because while it blocks TEWL, it also blocks cellular respiration necessary for barrier repair. Further, occlusion traps microorganisms under the petrolatum where they can breed in the moisture trapped therein. On the other hand, natural skin lipids, like omega 3-6 fatty acids, inhibit adherence of microorganisms to the stratum corneum.
Studies linking petrolatum to increased incidences of infections in preterm infants is ongoing and demonstrates mixed results. However, long term studies reflect a concern over the use of TPO protocols in NICUs. Petrolatum based ointments, like Aquaphor’s? twenty five year old formula, are the emollients of choice in NICUs. When one considers the changes in the standards of care in NICUs over the past three decades, perhaps now is the time to focus on new technologies in emollients that achieve skin care objectives without the aesthetic, epidermal challenges renders skin vulnerable to chemicals & infection, prevents normal TEWL & gland secretions, inhibits barrier repair, suppresses barrier recovery and reduces the epidermal proliferative response and microbial risk disadvantages of petrolatum.
To demonstrate the effectiveness of high products using molecular height silicones against petrolatum, Nutrashield TM was tested in a wash-off study against Aquaphor? and other leading skin barriers to determine each product’s ability to maintain skin protection after cleansing. As shown in Figure II, Nutrashield performed well against Aquaphor?, and did so while providing a breathable barrier instead of the occlusive barrier associated with Aquaphor? (a lanolin and petrolatum-based product). In clinical trials Nutrashield has proven effective in the treatment of skin breakdown in disordered and damaged skin, encountered in the wound care setting, as compared to previously available products.
Based on the above results, Medline Nutrashield outperforms products containing petrolatum levels as high as 49%, and petrolatum combined with 15% Zinc Oxide. Additionally, both Sensi-Care 2 and Sween 24 also contain Dimethicone as an active ingredient (Sween at 6% versus 1% in the Nutrashield). The extended performance of the Nutrashield is most likely due to the addition of Divinyldimethicone/ Dimethicone Copolymer, which has an internal phase viscosity that is greater than 100,000,000 cst in viscosity. As it is delivered in an emulsion form, it is capable of laying down a thin, but consistent and robust film.
An in-vitro study at an independent laboratory was conducted, to determine the effectiveness of Nutrashield and Skin Repair Cream in reducing e-TEWL. Collagen samples were cut into 4×4 inch squares. Each square was pre-coated with 0.1 g of product. The product was applied by rubbing a finger over the collagen material to simulate actual use for a 20 second period. The product was then allowed to dry for five minutes. Each square was placed over Fisher Payne Permeability Cups, containing 3g of water. The samples were placed in a 37 degree oven and checked every four (4) hours. After 24 hours the cups were removed and a final weight was recorded.
Figure III shows that both REMEDY Nutrashield and REMEDY Skin Repair Cream were effective at reducing e-TEWL without occlusion. Nutrashield provided a fourfold reduction in e-TEWL over the control, while Skin Repair Cream showed a twofold improvement. The objective of topical skin care intervention is not to stop all TEWL, just excessive TEWL.
Skin care for neonates is an emerging science. But, since the reduced risk of infant mortality is paramount, improved emollient treatments deserve thoughtful consideration. Skin care for the high-risk neonate requires knowledge of the unique aspects and physiology of their skin. During the neonatal period many newborns develop preventable, clinically apparent skin problems and many more, especially preterm neonates,