[Feer's disease].

Two sisters and their brother who had been exposed to mercury vapours from a broken fever thermometer were treated for acrodynia. Their urinary Hg concentrations, as well as the relatively few data that can be found in previous publications, show that the brain of children below the age of 5 years is much more sensitive to chronic mercury intoxication than the cerebrum of adults. Hg concentrations of well below 50 micrograms/l in the urine can be associated with severe symptoms. One of our patients had a mercury concentration of 6.3 micrograms/l. In adults with occupational exposure, urinary mercury concentrations of up to 200 micrograms/l are tolerated and permitted. Acrodynia possibly is not always diagnosed when it is occurring. Normal values for urinary Hg excretion in children under basal conditions and after administration of a chelating agent should be established.