Q: My 33-month-old baby has had a fever for 5 days. Do we need a blood test?

Medically reviewed by Sang Hyun Ahn, 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 33-month-old baby has had a fever for 5 days. It initially started on Saturday after a nap. The doctor said it seemed like the early stages of a cold, so we received a 4-day prescription that included antibiotics and cough/sputum medicine. The fever dropped today, and since we ran out of medication, I went back to the clinic for a refill.

However, after waking up from a nap today, the baby's fever returned. Today marks the 5th day of the fever. Do we need to see the doctor again or get a blood test? The baby's overall condition is good, except for struggling a bit with a runny nose. I heard that a blood test is recommended if a fever lasts for more than 5 days. What should I do?

Answer:

You must be worried about the fever repeating for the 5th day. It is especially anxiety-inducing when the fever returns after seeming to improve with medication.

[Current Situation Assessment]

• Fever persisting for 5 days = Time to consider additional tests

• Good overall condition = A positive sign

• Fluctuating fever = A common pattern, but the exact cause needs to be identified

[Recommended Actions]

1. Visit the clinic again tomorrow morning

→ For fevers lasting 5 days or longer, a blood test helps differentiate between bacterial and viral infections.

→ It will check for hidden infections like pneumonia or urinary tract infections.

2. Tonight's management:

• Fever reducer: Tylenol 10-15mg/kg (every 4-6 hours)

• Plenty of hydration (offer water or electrolyte drinks frequently)

• Light clothing, cool room temperature

[Go to the ER immediately if:]

→ Having difficulty breathing

→ No urination for over 8 hours

→ Cloudy consciousness or lack of response

→ High fever of 40°C (104°F) or above persisting

A 5-day fever may have causes other than a simple cold, making a blood test necessary. It is a relief that the baby's overall condition is good, but I recommend getting another medical examination tomorrow.

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