Fever of Unknown Origin in Newborns

Fever of Unknown Origin in Newborns

Fever of unknown origin (FUO) — is a clinical situation in which the child has a prolonged fever (usually more than 1-2 weeks), the cause of which cannot be identified using standard diagnostic methods. In newborns this diagnosis is made with great caution and is a reason for hospitalization and very thorough examination.

Diagnostic workup: Excluding the most dangerous

For a newborn, prolonged fever without an obvious cause is always suspicion of a serious hidden infection. The diagnostic workup performed by physicians is aimed at ruling out life‑threatening conditions:

• Hidden bacterial infections:
  • Urinary tract infection (UTI): May occur without specific symptoms other than fever.
  • Osteomyelitis: Infection of bone tissue.
  • Hidden abscesses.
• Systemic infections: Tuberculosis, cytomegalovirus infection, toxoplasmosis.
• Oncological diseases (extremely rare at this age): Such as neuroblastoma or leukemia.
• Autoimmune/autoinflammatory diseases: The debut of some of them can occur even at an early age.

What should parents do?

If your child has a persistent fever for a long time without obvious cold symptoms, do not self‑medicate. It is important to see a pediatrician. Keeping a detailed daily log where you record the temperature level, time of onset and any, even minor, changes in the child's behavior can greatly help the doctor in the diagnostic workup. Read about general mechanisms in the article "Fever of Unknown Origin".