[Relapsing fever after travelling in the tropics; a story with a twist]

Relapsing fever is an infectious disease caused by Spirochaetes. The presentation is characterised by recurrent episodes of fever.

At the end of her trip through South Africa and Botswana, a 54-year-old woman had symptoms of fever and dry cough. Back in the Netherlands, physical examination at the emergency department did not reveal any abnormalities besides fever. Laboratory investigation found thrombocytopenia and elevated infection markers. Thick blood smear revealed the presence of Spirochaetes. Following a working diagnosis of 'relapsing fever', the patient was treated with doxycycline. There was no Jarisch-Herxheimer reaction. At a follow-up outpatient appointment two weeks later, the patient had fully recovered.

Relapsing fever is a rare disease without specific symptoms. The diagnosis is therefore easily overlooked. Untreated, mortality is high. During episodes of fever, the diagnosis can be established with a thick blood smear.