Q: My child's leg pain returned after being treated for post-flu muscle inflammation. Should we see a doctor tomorrow?

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:

My child developed muscle inflammation as a complication after having the flu. The inflammation markers had gone down, but today they are complaining of leg pain again. Should we see a doctor tomorrow?

Here is the timeline of events:

- Saturday/Sunday: High fever of 39-40°C (102.2-104°F).

- Monday/Tuesday: The fever went down, but leg pain started (pain from the back of both knees up to the upper calves).

- Tuesday: Visited the clinic and had a blood test.

- Wednesday: The muscle inflammation marker, which is normally up to 200, came back at 600. We immediately went in, received IV fluids (glucose) for 4 hours, and came home.

- Thursday: No pain, and the doctor said the inflammation markers dropped (I don't know the exact number).

- Friday (Today): Starting this afternoon, the pain returned in the same area of one leg.

The clinic that did the blood test is closed tomorrow (Saturday). Should we go to an orthopedic clinic, another pediatrician, or just monitor the situation at home?

Answer:

It sounds like your child is dealing with post-influenza myositis (muscle inflammation), which is a known complication of the flu. You have done a great job monitoring their condition and getting prompt care so far.

To summarize the current situation, the CK (creatine kinase) muscle enzyme level was 600 on Wednesday, dropped after IV therapy on Thursday along with the pain resolving, but the pain has now returned in one leg today (Friday).

What to do at home right now:

- Ensure plenty of fluid intake. Dehydration can worsen muscle damage, so keeping your child well-hydrated is crucial.

- Restrict strenuous physical activity and let your child rest in a comfortable position.

- Monitor their urine color closely. If the urine turns dark brown or cola-colored, this requires immediate medical evaluation on the same day.

Should you see a doctor tomorrow?

Please visit another pediatrician or an emergency room tomorrow if any of the following occur:

- The urine turns dark brown or cola-colored.

- The pain becomes severe enough that your child has difficulty walking or bearing weight.

- A high fever (≥38.5°C or 101.3°F) returns.

- Your child experiences general weakness, vomiting, or decreased consciousness.

If your child does not have any of these severe symptoms, the pain is mild, and they are drinking fluids well, you can safely monitor them at home over the weekend and visit your original pediatrician on Monday.

Which doctor should you see?

- First choice: Your original pediatrician who performed the blood tests (when they reopen on Monday).

- If care is needed tomorrow: Go to another pediatrician or the pediatric emergency room. They can recheck the CK levels and determine if more IV fluids are necessary.

- Orthopedic clinics: These clinics primarily deal with bone and joint issues (like fractures), so a pediatrician is much more appropriate for monitoring and treating post-viral myositis.

When you do follow up with a doctor, be sure to ask if the CK levels need to be rechecked, what the clinical criteria are for additional IV fluid therapy, and how long your child's physical activities should be restricted. Please continue to monitor their urine color, pain level, and temperature, and seek prompt in-person medical care if any of the warning signs mentioned above appear.

For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.

https://fevercoach.us