WAIKOLOA, HAWAII – Ruling out herpes simplex virus infection is the first order of business in any neonate who displays interrupted skin integrity, whether in the form of erosions, vesicles, pustules, erythroderma, or purpura.
"Always think about [herpes simplex virus (HSV)] in neonates with interrupted skin integrity. HSV is first, second, third, fourth, and fifth on my differential diagnosis list," said Dr. Albert C. Yan, director of pediatric dermatology at Children’s Hospital of Philadelphia.
"This can be a devastating disease. The main issue is that a lot of people don’t recognize it until the later stages. Prompt recognition and initiation of empiric therapy when you’re even remotely thinking about neonatal HSV can significantly reduce morbidity and mortality. Once the work-up is negative, you can stop," he said at the Hawaii Dermatology Seminar sponsored by Skin Disease Education Foundation (SDEF).
Dr. Yan highlighted findings from a recent large retrospective cohort study led by investigators at Cincinnati Children’s Hospital Medical Center that underscored the importance of early treatment. The study included 1,086 neonates with HSV at 41 tertiary-care children’s hospitals. The babies were a median of 10 days old when hospitalized.
Three-quarters of the neonates were started on intravenous acyclovir within 1 day after hospital admission. Their in-hospital mortality was 6.6%, as compared to 9.5% in the remaining one-quarter of children who received delayed acyclovir, defined as treatment initiated on day 2-7 after admission. Of neonates with delayed acyclovir, 86% started on the antiviral agent on day 2 or 3 of hospitalization.
In a multivariate logistic regression analysis adjusted for differences in illness severity between the two groups, delayed commencement of intravenous acyclovir was independently associated with a highly significant 2.6-fold increased risk of in-hospital mortality (Pediatrics 2011;128:1153-60).
Dr. Yan noted that common systemic signs of neonatal HSV in term babies include lethargy, temperature instability, hypotension, and transaminitis.
"HSV is first, second, third, fourth, and fifth on my differential diagnosis list."
In contrast, premature babies with neonatal HSV are much more likely to have respiratory distress as a presenting feature. Their onset is earlier – typically within 2 weeks in the NICU – and the infection’s mortality and neurologic sequelae are greater than in term infants.
Both term infants and preemies can develop neonatal HSV in the absence of maternal genital HSV lesions at delivery or even a maternal history of HSV.
Most cases of neonatal HSV infection involve HSV-1; however, HSV-2 disease is far more severe. "Those are kids you’re going to have to monitor more closely because they’re more likely to have dissemination and CNS disease and more likely to have a fatal outcome," the pediatric dermatologist cautioned at the seminar sponsored by the Skin Disease Education Foundation.
Skin vesicles are often absent in neonates with HSV. To maximize the diagnostic yield of testing by PCR or culture, it’s important to obtain swabs from multiple sites, including oral and nasopharyngeal secretions, blood, cerebrospinal fluid, and the trachea, as well as skin.
Dr. Yan reported having no financial conflicts.
SDEF and this news organization are owned by Elsevier.