Myth #10: A fever after immunizations is normal…
If a child presents to the Emergency Department with a fever after immunizations, and they have no overt clinical signs of infectious source, do they need a work-up? Do immunizations actually cause fevers? What does the evidence say? This is part 10 of a 10-part series where I will be busting what I consider to be the top 10 myths involving pediatric fever.
Just 1 study to look at for this section….
Wolff M, 20091
- 2009 study of 1,978 infants aged 6-12 weeks of age.
- 213 of them received recent immunizations and the rest did not.
- The goal was to assess the rate of Serious Bacterial Infection 1 and 3 days after Immunization in comparison to children who did not receive a recent immunization
- The incidence of Serious Bacterial Infection within the first 24 hours after an immunization was only 0.6%. Pretty low, but there is still a risk.
- After 24 hours, the incidence of serious bacterial infections increased to 2.8%. However, it is important to point out, that in this study, all of the serious bacterial infections after recent immunizations were due to urinary tract infections.
- In children who have not received a recent immunization, the incidence of a serious bacterial infection was higher at 7% and included all causes of SBI, including UTI’S, Bacteremia, Meningitis and Pneumonia.
Let’s summarize the evidence…
- This approach should only be considered for the well appearing infant > 60 days old. There just isn’t enough literature of fever after immunizations in the neonatal period to change our practice. For infants aged less than 60 days old, I strongly suggest approaching the child like you would any neonatal fever based on age.
- In children > 60 days old who present < 24 hours after an immunization and looks well with no sign of infectious source, it is reasonable to check a urinalysis and arrange close follow up.
- Any age child presenting > 24 hours after immunization, you should approach the child like any other infection
So, for our tenth and final myth questioning if recent immunizations cause fever…I would consider this one PLAUSIBLE
There you have it. My evidence-based review to the top 10 myths related to pediatric fever. If you enjoyed the content, don’t forget to subscribe below to get new articles sent directly to your email. But most importantly, don’t forget…never stop learning.
Resources
- Wolff M, Bachur R. Serious bacterial infection in recently immunized young febrile infants. Acad Emerg Med. 2009 Dec;16(12):1284-1289. doi: 10.1111/j.1553-2712.2009.00582.x
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