The skin of premature neonates is only a fraction the thickness of a full term infant which makes it a poor barrier to the environment. The immature skin does not retain water as well as mature skin and is more vulnerable to wounds, both of which are determinants of neonatal infection. The skin provides a vector for hospital acquired and other infections which cause more than 900,000 deaths per year, worldwide.
Mechanism of Action
Emollient ointments are commonly used to treat dry skin in all populations as they help the body retain moisture. Since preterm neonatal skin is particularly fragile and an inferior barrier to pathogens than fully developed skin, a periodic treatment of emollient over most of an infant's body is sometimes used to provide an additional barrier and to help the skin develop.
Emollients have been used to improve the condition of neonatal skin for centuries and recent research has explored the effects and potential of this practice. Most promisingly, Aquaphor and sunflower seed oil have been found to decrease the chance of mortality notably by decreasing the chance of hospital acquired infection. The researchers found that a twice daily whole body treatment of aquaphor for two weeks after a preterm birth decreased mortality by 32%.
Unfortunately, recent research has also found damaging effects of some emollients in some circumstances. The most commonly used traditional emollient for neonates, mustard seed oil, has been found to have a generally damaging effect on the skin's function as a barrier. Even Aquaphor, a highly developed barrier, is not always helpful. A multicenter trial in the United States found it to actually increase the incidence of infection among premature neonates of birth-weight less than 1kg.
Current use in High-Resource Settings
Emollients are not used as a generalized skin treatment for neonates in high-resource settings. Instead, moisturizers of various kinds are used to treat particular skin conditions and wounds.
Current use in Low-Resource Settings
The most common use of emollients in low-resource settings is mustard oil in southern Asia. However, it may be toxic to keratinocytes of the skin. In south Asia and elsewhere, a variety of other emollients, including sunflower seed oil, are used by hospitals and traditional birth attendants. Furthermore, the research and WHO report have renewed interest in the medical use of whole body emollient treatment of preterm neonates, though it is not obvious how widespread adoption has been.