When a Spinal Tap May Be Necessary for Infant Fever

Your three-week-old baby has a temperature of 101 degrees Fahrenheit and you have just called your pediatrician. You were expecting a little simple reassurance since you have often been told that you overreact when your older kids have had a fever. Instead, you are a little surprised when your pediatrician tells you to go straight to the emergency room.

Mother checking temperature of young son
Jamie Grill / The Image Bank / Getty Images 

You are no longer just surprised and are now getting nervous, when the ER staff rushes you to a room, ahead of a waiting room full of kids with runny noses and coughs. An ER doctor comes in and talks to you about your baby's symptoms, examines her, and then explains that she is going to need a full septic workup. You still don't fully understand what is happening, but then you hear the two words that frighten many parents of young children with fever—spinal tap.

Although many parents get through their baby's first few months without a fever, unfortunately, this scenario occurs hundreds of times a day in emergency rooms all over the country.

The Septic Work-Up

Unlike older children, it can be difficult to tell when a newborn or young infant is seriously ill. In fact, an infant under two or three months of age may have a serious bacterial infection, such as meningitis (an infection of the fluid surrounding the brain and spinal cord), bacteremia (a blood infection), or a urinary tract infection and still appear totally fine. That is why doctors routinely do a septic workup on infants who are under two or three months old when they have a rectal temperature that is at or above 100.4 degrees Fahrenheit. This septic workup typically includes a:

  • Complete blood count
  • Blood culture
  • Urinalysis and urine culture
  • Spinal tap so that doctors can order an examination of the spinal fluid, including a spinal fluid culture
  • Chest X-ray (although this is often left out if the child lacks respiratory symptoms)
  • Stool studies if the baby has diarrhea
  • Viral test or culture, such as an RSV prep or flu test

Depending on these test results, a young infant with a fever may be started on antibiotics and may be hospitalized and observed for 24 to 48 hours. Infants over 28 days old may simply be sent home, with a follow-up visit to the emergency room or with their pediatrician if all testing is normal and the baby is feeding well.

What Causes Babies to Have a Fever?

Just like older children, a baby's fever can be caused by a viral infection. Unfortunately, bacterial infections, which can be more serious than simple viral infections, are more common in younger children than in older children and young adults.

Does Your Baby Really Need a Spinal Tap for a Fever?

Although parents often think that today's pediatricians are too aggressive when treating young babies with fever, it is important to note that current practices are actually much less strict than they used to be. It wasn't too long ago when all children under three months of age with a fever were actually admitted to the hospital after their septic workup and observed for at least 24 hours. Now admission is typically reserved for all newborns and only those older infants who appear ill.

Even the need for spinal taps is being questioned. While they were once routinely done on all infants with a fever if they were under three months of age, some experts have lowered that age to 31 or 60 days if the child meets certain screening criteria and can be closely followed by his doctor.

Keep in mind that a spinal tap is actually a simple procedure for an infant with few complications and is often tolerated well. If you consider the consequences of untreated bacterial meningitis, which a spinal tap can help detect, then the question of whether or not to let a doctor perform a spinal tap on your child gets easier.

If you refuse a spinal tap, the doctors in the ER will likely try to talk you into it. It is the standard of care, meaning that is what doctors typically do because of current recommendations or experience, for a baby or young infant to get a spinal tap. It would be unusual for a doctor to let a baby home from the ER without a spinal tap if they thought it was necessary that it be done. What would they do if a parent still refused after a long discussion of the risks and benefits? It would likely depend on the situation, but it might range from observing the infant in the hospital to calling child protection services and charging the parent with medical neglect.

Avoiding Viruses and Fevers

To help avoid fevers and the need for a septic workup, it can be a good idea to help limit your baby's exposure to people in the first two or three months of her life. In particular, every person that holds the baby should wash their hands thoroughly. Those people who are unwell—even with a cold—should not handle the baby. That may sound silly to new parents who want to show off their new baby, but the consequences may be exposing your baby to viruses and other germs, a fever, and a trip to the ER for a spinal tap.

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  1. National Institutes of Health. Detecting bacterial infections in newborns. Updated September 13, 2016.

  2. Aronson PL, Wang ME, Shapiro ED, et al. Risk stratification of febrile infants <60 days old without routine lumbar puncture. Pediatrics. 2018;142(6):e20181879. doi:10.1542/peds.2018-1879