The systemically unwell child

Abstract

The systemically unwell child is a common clinical problem in paediatrics. In most cases the cause is infection, and the child will usually improve spontaneously or following appropriate therapy. When routine investigations fail to reveal an aetiology and the child remains unwell, the differential diagnoses should be broadened to include, among others, paediatric rheumatic diseases. This chapter provides a brief overview of these conditions focusing on key clinical features, common diagnostic pitfalls, and investigations important in their diagnosis. The important rheumatologic differentials of systemic illness in children according to the age at which they typically occur and a summary of the key clinical and laboratory features of these conditions are presented. Once rheumatologic differentials relevant to the age of the child under evaluation are identified, they can be refined based on knowledge of the incidence and clinical and laboratory features of the diseases concerned.