Severe hypokalaemia: is one reason enough?

Hypokalaemia is a common electrolyte disorder with a straightforward differential diagnosis. The usual suspects are diarrhoea, vomiting or intake of diuretics. In some patients, a spot urinary chloride may help to tell the tale. Occasionally, a comprehensive workup is required [1] to elucidate disorders such as Conn’s, Bartter’s or Gitelman’s syndromes. Sometimes, however, the cause of hypokalaemia may be all too obvious and one of the usual suspects later turns out to be an innocent bystander rather than the primary culprit. We present such a case to illustrate a common but dangerous error in medicine, namely our intention to frame all available information into an all too obvious diagnosis.