May 2000
SAN FRANCISCO - Neonatal dermatology is changing rapidly, as infants born at low gestational ages and birth weights are becoming increasingly viable. This creates unique challenges for the practicing clinician.
"The skin of the preterm infant is really quite different than that of a term infant," said Lawrence F. Eichenfield, MD, of the Children's Hospital, San Diego, University of California at San Diego. "The skin of a term neonate is 40% to 60% thinner than adult skin, and premature infant skin is markedly thinner. When we're looking at very premature infants, understand that we're just seeing them at some time during their normal skin development."
![[bar]](/art/gradred.gif){kind=small}
Translucent thin
skin of a 25-week gestation infant with erosions and crust secondary
to lead trauma.
Photo courtesy of Lawrence F. Eichenfield,
MD
Knowledge of premature infant skin development has
improved greatly in the last several years. Previously, it was thought that
premature infant skin would develop within two weeks. This principle does not
hold true for those younger than 30 weeks' gestation at birth, said
Eichenfield, who spoke here at the American Academy of Dermatology 58th Annual
Meeting. A recent study, in the Journal of Investigative
Dermatology, showed that in very premature infants, epidermal function
maturation could take as long as nine weeks.
"We have a set of infants who have very immature epidermis for an extended period, and there are clinical consequences to this," he said. The premature infant's skin is vulnerable to many types of injury.
Topical agent toxicity is a particular concern. "Little infants have more surface area as compared with their body mass and thus can absorb more," he said. For example, povidone-iodine swabs, which have been used for minor surgical procedures, can cause neonatal hypothyroidism. This can be a problem, because "hypothyroidism in very premature infants has been associated with an increased risk of cerebral palsy.
Premature infant skin is "more vulnerable to burns, frictional forces and tortional forces," Eichenfield said. "This can contribute to increased water loss, problems with electrolytes, with thermal regulation and increased risk of local or systemic infection, as well as vulnerability to mechanical forces."
Fine linear
cigarette paper-like scar on the trunk in a child with truncal aplasia
cutis congenital.
Photo courtesy of Lawrence F. Eichenfield,
MD
Simple measures may minimize injury to neonatal skin. Use
of emollients may improve the barrier function of premature skin, Eichenfield
said. In two recent studies, each involving a small number of infants,
application of emollients in the first two weeks of life decreased
transepidermal water loss, dermatitis and bacterial colonization.
Minimizing the use of tape is important, as is delaying lead removal. Water-soaked cotton is the preferred method of lead removal to avoid alcohol absorption problems. Soft gauze wraps for pulse oximeter leads may be helpful.
Biopsy may be an important tool for diagnosing premature infants with subtle skin changes. "There's an increased incidence of aspergillosis and other opportunistic infections that are seen in very low birthweight infants," Eichenfield said. When erythematous pustules are observed in very low birthweight infants, "consider fungal disease in the differential and be more liberal with biopsies than you might be in the full-term neonate or a child a few months of age."
A placenta with
fetus papyraceous.
Photo courtesy of Lawrence F. Eichenfield,
MD
Maternal history may be important in making an accurate
diagnosis as well. Eichenfield cited an infant with linear streaks on the
abdomen that felt like cigarette paper as well as a small area on the scalp
that looked like it had eroded and was starting to heal. The diagnosis was
scalp and truneal aplasia cutis congenita, secondary to demise of a fetal twin.
This was confirmed when a fetus papyraceous was found in the placenta.
"At the time, it was thought that this child had only subtle lesions clinically," Eichenfield said. "But the association of truncal aplasia cutis congenita and fetus papyraceous is associated with other systemic problems, which can include cardiac disease, central nervous system disease and bowel disease. In fact, this child has severe mental retardation and a seizure disorder that was found on follow-up at about 6 months of age. If it weren't for the subtle physical findings and us happening to look at the placenta, they wouldn't have a reason for this child having a CNS disease. Even things that aren't very impressive may be harbingers of ... problems."
For more information:
- Eichenfield LF. Neonatal dermatology. Session CRS103. Presented at the American Academy of Dermatology 58th Annual Meeting. March 10-15, 2000. San Francisco.
You can
express your views on this article, or other relevant themes, in the
Infectious Diseases in Children
Specialty Forums.