Q: My child has had a mild fever for 4 days, seems lethargic, and has a poor complexion. Should we test for the flu?
- Myeongchan Kim, MD
- Jul 12
- 2 min read
Updated: Jul 21
Medically reviewed by Sang Hyun Ahn, MD
Content edited by Myeongchan Kim, MD
This post is a dramatization of a question and answer session experienced by our actual medical reviewers. Please note that this content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
Question:
Four days ago, my child suddenly developed a high fever of 39°C. After alternating fever reducers for a day, the fever dropped, but a mild fever of around 37.7°C has persisted for the past four days. We saw a pediatrician the day after the fever started. The doctor mentioned that if it were the flu, the high fever would have continued, so they didn't run a flu test and only prescribed throat cold medicine without antibiotics.
Currently, there is no high fever, and it sounds like there might be some phlegm, but there are no other obvious symptoms. However, my child seems very lethargic and has a poor complexion. Since my child cannot speak yet, I don't know if anything else hurts or feels uncomfortable. Should we go back and request a flu test, or should we just keep giving the prescribed cold medicine and observe at home?
Answer:
It is completely understandable that you are worried, especially since your child has had a prolonged mild fever, appears lethargic, and has a poor complexion.
Based on your description, the most important and concerning signal right now is that your child is lethargic and looks unwell, even though the initial high fever of 39°C has decreased to a mild fever of 37.7°C.
Regarding the flu test: Flu tests are most accurate when performed within the first 48 hours of symptom onset. Since it is currently the fourth day, the accuracy of a rapid flu test will be significantly lower. However, because your child is lethargic, a follow-up visit to the doctor is highly recommended rather than just observing at home.
Please seek immediate medical attention if you notice any of the following:
Refusal to drink fluids or a noticeable decrease in urine output.
Fast breathing or chest retractions (the chest sinking in with each breath).
Worsening lethargy, extreme sleepiness, or delayed reactions.
When you revisit the doctor today, they will likely evaluate:
The possibility of pneumonia (through a stethoscope exam or a chest X-ray, if necessary).
Your child's level of dehydration.
Whether any blood tests are needed to check for other infections.
At-home care in the meantime:
Offer fluids frequently in small sips to prevent dehydration.
Use a humidifier to help with the phlegm.
Continue to observe your child's overall condition very closely.
A lethargic appearance and poor complexion are warning signs that require more medical attention than a simple common cold. Please make sure to have your child re-evaluated by a pediatrician today.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
