Q: My 7-year-old was recovering from Mycoplasma, but her cough worsened and she has a runny nose. Can she be reinfected by her sibling?
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 7-year-old daughter (22kg) has been dealing with a cough for 18 days. She started coughing on October 31. She was diagnosed with Mycoplasma on November 7 and was treated with antibiotics (Azithromycin), steroids, and a nebulizer.
By November 14, her cough had significantly improved, and her phlegm was gone. However, on November 16, her cough suddenly worsened. We visited the pediatrician, who prescribed different antibiotics and steroids. The doctor mentioned her chest sounded clear and the lungs were not getting worse. Now (November 17), her cough is getting worse, she complains of an itchy throat, and she has developed a runny nose.
Is it normal for Mycoplasma to improve and then worsen? Could this be a new illness? The nebulizer doesn't seem to be working. Also, her 10-year-old older sibling just caught Mycoplasma from her and is currently on antibiotics. Is it possible for my 7-year-old to get reinfected by her sibling?
Answer:
It sounds like you have been through a lot managing your child's illness over the past 18 days.
Characteristics of Mycoplasma Progress
Even after starting antibiotics, a Mycoplasma cough can persist for 2 to 4 weeks. It is not uncommon for symptoms to temporarily improve and then worsen again. Airway inflammation takes time to fully subside. Furthermore, while reinfection with Mycoplasma is rare because immunity typically lasts for several months, if another viral cold is circulating in the household, it can overlap with the current illness and cause new symptoms like a runny nose.
Reinfection vs. Co-infection
Since Mycoplasma reinfection is very rare in such a short timeframe, it is highly likely that your older child or another source introduced a different common cold virus to your 7-year-old. It is best for both children to wear masks, practice good hand hygiene, and use separate rooms and towels to minimize cross-infection.
Home Care Measures
Hydration and Humidity: Encourage her to sip water frequently in small amounts and maintain indoor humidity between 40-60%.
Elevate the Upper Body: Use one or two pillows to slightly elevate her head while sleeping.
Honey: Since she is over 1 year old, giving her 1 teaspoon of honey before bedtime can help soothe the cough.
Medications: Continue the newly prescribed antibiotics and nebulizer treatments exactly as directed by your doctor.
When to See a Doctor Immediately
Please have her re-evaluated by a doctor today if you notice any of the following red flags:
Fast breathing (more than 30 breaths per minute while resting) or the skin pulling in under her ribs (retractions).
Bluish lips or fingernails.
Refusal to drink water/eat, or no urination for more than 8 hours.
A return of high fever (≥38.5°C) or a fever lasting more than 3 days.
A cough so severe that it completely prevents her from sleeping at night.
If none of these warning signs are present and she is eating, sleeping, and playing relatively well, you can continue to observe her at home and schedule a follow-up visit with your pediatrician in 2 to 3 days. However, if her breathing pattern changes or the cough continues to worsen, please seek an in-person medical evaluation immediately.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
