A deadly capillary leak attack. Clarkson's disease; a narrative review.A previously 42-year old healthy man was brought in by an ambulance to the emergency department with symptoms of a distributive shock. He experienced a rapid decline in his clinical state that evolved into a cardiac arrest. Despite all the performed measures and a prolonged resuscitation, the patient died a few hours later without an initial clear diagnosis. Lab results showed an extremely high haemoconcentration leading to further investigations which suggested the possibility of Clarkson's disease, although septic shock as an alternative diagnosis could not be excluded. Nevertheless, because of its presentation, especially emergency and intensive care physicians should be aware of the existence of this condition in the event of an unexplained refractory distributive shock in combination with haemoconcentration and hypoalbuminemia given its possible fatal outcome.