A 23-year-old man, previously fit and well, presented with an atypical
pneumonia, associated with microangiopathic anaemia, thrombocytopenia
, rhabdomyolysis and renal impairment. Despite administration of intra
venous fluids and antibiotics, his condition rapidly deteriorated, and
the possibility of an aggressive connective tissue disorder was raise
d. Thus he was treated with high-dose oral steroids and plasma exchang
e until autoantibodies were shown to be negative. At this stage it tra
nspired that the patient had swallowed water from a stream three weeks
earlier, and leptospira antibody titres were subsequently found to be
elevated. Antibiotics were continued, acid after a protracted course
he made a full recovery. Leptospirosis should be remembered as a rare
cause of atypical pneumonia, particularly if there is associated hepat
ic or renal impairment.