This section refers to the child with fever that is persistent or recurrent for longer than 5 days without an apparent cause.
Key points to consider are:
- Careful clinical assessment to exclude red flags (suggestive of malignancy or infection), foreign travel, history of tick bites and health of family members, pets and their health, medication history, sexual history.
- Careful examination (looking for rashes especially when pyrexial), lymphadenopathy, mouth ulcer, evidence of heart murmurs or nail fold changes (endocarditis), joints and fundoscopy.
- 'First line' investigation aim to exclude infection and autoimmune disease and usually includes: Blood cultures when pyrexial, Urine microscopy and culture, Autoantibodies, Chest radiograph, Cerebrospinal fluid analysis.
- Always consider Kawasaki disease.
- In the immunosuppressed child (either due to underlying disease or treatment), always consider unusual / opportunistic infections.
- Further investigation is dependent on the clinical context and includes Abdominal Ultrasound / MRI / CT / Angiography and Bone marrow (to help exclude malignancy and infections).
- If fever is lasting more than 7 days and is of a quotidian pattern (i.e.recurrent paroxysms of fever with the child normal in between) then systemic JIA is more likely. It is important to check for rash especially in the evenings when the fever is high - the rash may be more on the inner thighs, inner arms or trunk so it is important to expose the child as appropriate.
Conditions to consider in the differential diagnosis
Auto-immune / Autoinflammatory disease
More information about periodic fever syndromes and the spectrum of autoinflammatory disease is available.
The chart below shows recurrent fever in a child with systemic JIA - the fever peaks are often in the evenings (quotidian pattern) and often associate with rash (photo)