Long-term fever in a child: what is the reason, how to examine, treat or not treat?

Abstract

Long unclear fever in children of different ages remains one of the difficult and topical issues in the paediatric practice. Despite up-to-date techniques of laboratory and instrumental examination, verification of prolonged fever causes remains difficult; it cannot be deciphered in 10% of cases. It is especially important to differentiate fever from hyperthermia in paediatric practice. The article provides an overview of the status update on the issue. The mechanisms of fever and hyperthermia are described, criteria for fever of unknown origin are given. It is stated that infectious diseases under the guise of fever of unknown origin develop in 60–70% of children. Systemic connective tissue disease and vasculitis are detected in 20% of cases, hemato-oncological – in 5%, auto-inflammatory – in 5%, the cause of fever remains unknown in 10% of cases. The article provides clinical observations of children with diseases debuting as fever of unknown origin with the following diagnoses: juvenile rheumatoid arthritis (JRA), a systemic variant with high activity (DAS index 28 = 5.1 at the rate of < 2.6); mucocutaneous lymphonodular syndrome (Kawasaki syndrome), damages of cardiovascular system (small coronary artery aneurysms), bacterial-viral infection; auto-inflammatory syndrome – mevalonate kinase deficiency syndrome (hyper-IgD syndrome). Diagnostic approaches to the verification of febrile condition are outlined. It is noted that treatment should not be started in a stable condition of the patient without establishing the cause of the fever, and it is advisable to use only an antipyretic agent with central and peripheral effects, pronounced antipyretic effect, analgesic and anti-inflammatory effects.

Keywords

• fever
• hyperthermia
• fever of unknown origin
• autoimmune diseases
• neoplastic diseases
• juvenile rheumatoid arthritis
• antipyretics