A 38-year-old, previously healthy woman was admitted with non-oliguric acute renal failure. Prior to admission she had a 2-week history of sudden fever with a peak of 40◦C, lower back pain, severe headache, abdominal pain, emesis, increasing faintness and impaired vision. Initially she was admitted to a surgical unit, where the symptoms resolved within 3 days. Physical examination showed a weight gain of 5 kg, oedema of the lower legs and a butterfly rash (Figure 1). She lived in a forest area and regularly collected firewood. Laboratory results are shown in Table 1. A kidney biopsy was performed, which showed the images in Figures 2 and 3a–c.