Q: My child has a persistent fever around 38°C despite negative flu, COVID, and RSV tests. Should we repeat the flu test?
- Myeongchan Kim
- 18 hours ago
- 2 min read
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:
Yesterday afternoon, my child's temperature was 38.4°C. I gave them a fever reducer and took them to the clinic, where the doctor mentioned their throat was swollen. The doctor suggested running a flu test if the fever continued. Here is the timeline of the fever since then:
2 AM: 38.0°C
8 AM: 38.0°C (We did flu, COVID, and RSV tests, which all came back negative)
2 PM: 38.0°C
10 PM: 38.6°C
It has been two hours since the 10 PM reading, and the fever is still at 38.0°C. Since the fever is ongoing, should we get the flu test done again?
Answer:
I understand you must be very worried about your child's persistent fever.
To summarize the current situation: your child was diagnosed with a throat infection (pharyngitis) yesterday and tested negative for the flu, COVID-19, and RSV today. The fever continues to fluctuate between 38.0°C and 38.6°C, but it appears to be partially responding to fever reducers.
Regarding whether to repeat the flu test:
Even if an initial test is negative, testing again within 48 hours of symptom onset can sometimes yield a positive result. However, if a fever lasts for more than 3 days, or if the child develops symptoms like a cough, difficulty breathing, lethargy, or a decrease in fluid intake, a comprehensive re-evaluation of their overall condition by a doctor takes priority over just repeating the flu test.
Please visit your pediatrician or seek immediate medical evaluation if you notice any of the following warning signs:
• Difficulty breathing (e.g., skin pulling in under the ribs, nasal flaring).
• Extreme lethargy, limpness, or an inability to make eye contact.
• No urine output for more than 8 hours.
• Complete refusal to drink water or eat food.
• The fever continues into tomorrow, or new symptoms appear (such as a rash, severe headache, or vomiting).
What you can do at home right now:
• Encourage hydration by offering small sips of fluids (water, electrolyte solutions, or broth) every 5 to 10 minutes.
• Dress your child in light clothing and maintain a comfortable indoor temperature of 22–24°C (71–75°F).
• Administer fever reducers only when your child is visibly uncomfortable or in pain. There is no need to forcefully bring the temperature down to normal if they are resting comfortably.
• Absolutely do not use alcohol rubs or tepid water sponging, as these are no longer recommended and can cause discomfort or shivering.
If the fever persists or you are unsure about your child's condition, please follow up with your doctor for an in-person evaluation to determine the exact cause and the best next steps.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
