UK guidelines for the investigation and management of eosinophilia in returning travellers and migrants.

Eosinophilia is a common finding in returning travellers, migrants and other travelling groups. In this setting, it often indicates an underlying helminth infection. Infections associated with eosinophilia are frequently either asymptomatic or associated with non-specific symptoms but some can cause severe disease. Here the British Infection Association guidelines group has comprehensively reviewed and updated the UK recommendations for the investigation and management of eosinophilia in returning travellers, migrants and other relevant groups, first published in 2010.1 Literature reviews have been undertaken to update the evidence on the prevalence and causes of eosinophilia in these groups and on the treatment of relevant pathogens and clinical conditions. Diagnostic tests available to UK-based clinicians are summarised. Changes made to the guidelines include updates in the sections on the investigation and empirical treatment of asymptomatic eosinophilia and on the treatment of trichuriasis, lymphatic filariasis, onchocerciasis, hookworm, fascioliasis and taeniasis. Pathogens which are rarely encountered in UK practice have been removed from the guidelines and others added, including an expanded section on fungal infection. A section on off-license and rarely used drugs has been included.