MIAMI BEACH — Several neonatal vesiculopustular disorders can be life threatening, yet difficult to diagnose, Dr. Ronald C. Hansen said at the annual Masters of Pediatrics conference sponsored by the University of Miami.
Neonatal herpes simplex is among the most severe perinatal infections. The case-fatality rate is up to 85% in untreated neonates. As many as two-thirds of the survivors will have some, often neurologic, permanent disability. Infection with herpes simplex virus (HSV) is usually transmitted during labor and delivery, but in only about half of cases will there be a well-documented history of maternal exposure, said Dr. Hansen, professor of dermatology and pediatrics at Phoenix Children's Hospital.
Neonatal herpes can be a tough diagnosis because there are three different clinical patterns of infection: It can be mucocutaneous, can involve the central nervous system, or can be disseminated and involve multiple organs.
Skin lesions can be seen in all three patterns. Vesicles may be single or disseminated, lack an erythematous base, or be large, crusted coalescent erosions, not necessarily where the skin touched the cervix.
Biopsy can be helpful for confirming diagnosis, but it is no longer the preferred method. Rapid methods such as polymerase chain reaction assays, direct fluorescent antibody tests, and viral cultures are now available. Antiviral therapy with acyclovir is useful, but prognosis can be poor even if the child looks healthy and its cerebral spinal fluid is negative, he said.
Only 5% of all neonatal HSV cases are caused by in utero transmission, but that possibility should still be considered. Many of the infants don't appear sick despite multiorgan involvement. Infected infants are often premature and typically present with evidence of chronic infection, atrophy, and scars suggestive of epidermolysis bullosa or aplasia cutis congenita.
A high index of suspicion and the above studies for HSV are needed to confirm the diagnosis. If biopsies are performed, one should biopsy the skin because cultures of the nose, throat, rectum, and spinal fluid can be negative, Dr. Hansen said.
Bullous mastocytosis also may present with vesicles in the newborn period, and is readily confused with HSV or epidermolysis bullosa. Bullous mastocytosis is a rare form of mast-cell disease that can be distinguished clinically by its characteristic layering of blood in flat, intact blisters and red, wrinkly skin. A biopsy anywhere on the body would be positive because of the diffuse infiltration of the skin by mast cells, Dr. Hansen said.
Fetal varicella syndrome is another easy-to-miss diagnosis. Characteristic features include cicatricial lesions with a segmental or dermatomal distribution, and atrophic plaques that can resemble pan-sclerotic morphea. Other features can include neurologic and eye abnormalities, gastrointestinal and genitourinary malformations, and hypoplasia of one limb.
The risk of fetal varicella syndrome in children exposed to chickenpox in utero in the first trimester was estimated at 9%, although newer studies put it at only 1%–2%.
One should also consider neonatal varicella, which can be fatal. The disease is said to be more likely and more severe if the mother develops varicella 5 days before or 2 days after delivery.
This infant with intrauterine herpes simplex virus has deep atrophic and ulcerative lesions suggesting epidermolysis bullosa or aplasia cutis congenita. ©Elsevier, Inc./Pediatric Dermatology, 3rd Edition, p. 248, 2003