Herpes simplex virus can be acquired in utero. But that baby should have been diagnosed in the nursery and would still be in the hospital, not at an outside clinic. Infants with intrauterine infections are born with skin vesicles or scars, eye findings and either microcephaly or hydranencephaly (excess fluid in the cranium). They are really sick, and the ones that survive usually have severe long-term sequelae.
Herpes virus can be acquired during birth. Usually the virus is acquired in the birth canal of a mother with active herpes genitalis. However, infants delivered by C-section can also become infected. The mother may not necessarily be symptomatic at the time of delivery. The risk to the baby is higher if it is the mother’s primary infection. Trauma during birth, including placement of a scalp electrode, increase the infant’s risk of infection. Neonates can also pick up the infection after delivery if someone caring for them has a herpes infection, such as a cold sore (herpes labialis).
Neonates with herpes infection not acquired in utero come in three types. One group experiences skin, mouth or eye lesions at day 5-11 of life. This group can develop encephalitis or disseminated disease if they aren’t treated. Another group presents with encephalitis at 8-17 days of age. They look sick and are fussy, lethargic, may have poor tone or seizures and look like they have meningitis. The third group has disseminated disease when they arrive. They look septic. About three-quarters of them will have skin lesions, but be aware, 25% do not. The vast majority of these infants die. They typically present at 5-11 days of life.
What are you going to do when the baby gets here? Obviously, tend to the ABCs and basic resuscitation. Culture suspicious lesions. Cultures should also be obtained from the mouth or nasopharynx, eyes, urine, blood, rectum and CSF. Send the CSF for PCR as well. Then, start IV acyclovir. If the eyes are involved, the baby will also need topical treatment.
OK, you’re ready. Bring it on!
About 15 minutes later, the baby checks in. This is the most normal-appearing neonate you can imagine, with normal vital signs, great tone, and as far as you can tell, an impressive suck. The mom isn’t quite sure what the fuss is about. This is one of many babies she’s had and seems like all the others. She had no problems with the pregnancy or delivery. The baby is feeding well and acting great. So, why did the clinic think she had herpes?
The mother shrugs and tells you that it’s because of the sores in the back of her mouth. OK, fair enough. You go over and start your exam. The baby looks as good close up as she did from the doorway. Normal everything until you get to the mouth exam. As you gag the infant, sure enough, on the back of the hard palate are two vesicles on red bases set symmetrically in front of each tonsil. Time to dial down the adrenaline levels. This is not neonatal herpes. These lesions have the typical location and appearance of Bednar aphthae, which occur in the hard palate of newborns, on either side of the median raphe. Bednar aphthae lesions, which are frequently bilateral and symmetric, are felt to be due to trauma, usually from suctioning or being too rough with a nipple. They will go away in a few days and require no work-up or treatment.
You reassure the parents and send them home to enjoy their baby. No herpes work-up today. As a follow-up, you have the resident call and talk to the referring doctor. He has never heard of bednars aphthae, but was happy to learn the information.
Amy Levine, MD, is an associate professor of pediatric emergency medicine at UNC Chapel Hill
Need a good pictorial resource for pediatric emergencies?
Try Dr. Basil Zitelli’s Atlas of Pediatric Physical
Diagnosis (Mosby, $159).