Fever and rash

The patient presenting with fever and a rash presents a diagnostic challenge. While this syndrome suggests an infectious aetiology, the differential diagnosis remains broad, and requires a thorough history and physical examination to distinguish potential non-infectious causes. Epidemiological evidence is important in the differential diagnoses. The commonest febrile illnesses presenting with rash in the returned traveller are arboviral infections (dengue and chikungunya), infectious mononucleosis caused by Epstein–Barr virus (EBV) or cytomegalovirus (CMV), and tick-borne diseases (rickettsioses).