Thrombotic microangiopathy is a rare but serious manifestation of a variety of diseases. The key features are microangiopathic haemolysis, thrombocytopaenia, renal dysfunction and neurological symptoms. Here we discuss the case of a previously well male presenting with community acquired pneumonia who developed thrombotic microangiopathy during admission. This case illustrates the difficulties in the differential diagnosis and reminds us of the importance of the peripheral blood film in identifying the cause of thrombocytopaenia. One life-threatening cause of thrombotic microangiopathy is thrombotic thrombocytopaenia purpura and when that diagnosis is suspected emergency plasma exchange is essential. Many drugs can cause thrombotic microangiopathy and here we highlight the commonly-prescribed antibiotic levofloxacin as the culprit.
