Q: Can Mycoplasma recur? My child has repeating fevers and severe lethargy weeks after finishing treatment.
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 had a fever, cough, and bronchitis starting over a month ago. They tested positive for a resistant strain of Mycoplasma and were treated with macrolide antibiotics and steroids for 2 weeks. Due to a persistent low-grade fever and lethargy, they were prescribed a second-line antibiotic (doxycycline) for another 2 weeks, which we stopped about three weeks ago.
Recently, the child developed a runny nose and a fever of 38.5°C. For the past 6 days, a daily pattern has repeated: their temperature drops to normal in the morning, stays around 37.4-37.6°C during the day, and rises to about 37.8°C in the evening. They have a mild cough, some phlegm, and occasional body itching.
The biggest issue is that the child is extremely lethargic and drained. We visited the pediatrician today, who said their chest sounds fine and only prescribed cough and phlegm medicine. The fever pattern, lethargy, and itching are very similar to their previous Mycoplasma infection. Is a recurrence possible? Can a chest X-ray be clear if the breathing sounds are fine? I heard a PCR test might just detect the old bacteria. I am completely unsure if this is a recurrence or just a normal cold that is hitting them hard because their immunity is still recovering.
Answer:
I understand your concern, especially since the repeating fever and lethargy are so similar to your child's previous episode. It is very natural to feel anxious when a child remains this unwell after a long course of treatment.
Based on your description, we are looking at a 6-day repeating fever pattern (low during the day, rising in the evening), severe lethargy, mild respiratory symptoms, occasional itching, and normal chest sounds.
Recurrence vs. New Infection
While an actual recurrence of Mycoplasma is possible (it happens in about 10-15% of cases), it is more likely to be one of the following:
A new viral infection: Because your child's immune system is still recovering from a prolonged illness and antibiotic use, a regular cold virus can cause much more severe symptoms than it normally would.
Post-infection fatigue syndrome: Severe lethargy and fatigue can persist for weeks following a Mycoplasma infection.
Regarding Testing
Even if breathing sounds are perfectly normal through a stethoscope, a chest X-ray can sometimes still reveal signs of pneumonia or inflammation.
As you correctly noted, a PCR test can detect dead remnants of the previous bacteria, making it difficult to confirm if this is a true recurrence.
An antibody test (IgM/IgG) may be more helpful in this specific situation to determine current infection status.
When to Seek Immediate Medical Care
Go to the hospital or emergency room immediately if:
The fever stays above 39°C.
The child experiences difficulty breathing or chest pain.
They refuse to drink fluids or have no urine output for more than 8 hours.
Their consciousness is clouded, or they become unresponsive.
When to Revisit Your Pediatrician
Consider going back to the clinic within 2-3 days if:
The current symptoms worsen or last longer than 10 days.
The lethargy becomes even more severe.
Any new symptoms develop.
Home Care Guidance
Hydration and Nutrition: Offer plenty of fluids and easily digestible, nutritious foods in small, frequent amounts.
Environment: Maintain an indoor humidity level of 40-60%.
Rest: Avoid any strenuous activities and ensure they get as much rest as possible.
Monitoring: Keep a daily log of their fever pattern, symptoms, and energy levels.
Since your child has undergone a long period of treatment, their weakened immune system might just be making a regular cold feel much harder. However, because severe lethargy is the primary and most concerning symptom right now, I highly recommend consulting your pediatrician again to discuss further evaluations, such as a blood test or a chest X-ray, to rule out any underlying complications.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
