Mad Hatter’s disease

Mercury poisoning became an issue in the United States in New York City s hat-making industry in the early 1940s when it was noted that many workers in this industry displayed the same types of symptoms exhibited by the citizens of Minamata, Japan. This disease was often referred to as the Mad Hatter s disease. Since mercury nitrate was used in the production of hats, a study was conducted and the study linked the symptoms of workers with the use of mercury nitrate. As a result, the use of this hazardous chemical in the hatmaking industry ceased and a suitable substitute was found. 

Sometimes a professional starts to treat a behavior problem, but not the real cause. An example is mad hatter s disease or Danbury shakes. Employees in the hat-making industry around Danbury, Connecticut, were exposed to mercury and became nervous and irritable and exhibited shaking. Family or physicians did not recognize the relationship between the behaviors and exposure to mercury. 

O Carroll RE, Masterton G, Dougall N, Ebmeier KP, Goodwin CM (1995) The neuropsychiatric sequelae of mercury poisoning. The Mad Hatter s disease revisited. Br J Psychiatry 167 5-8 Palatsi R, Oksanen A, Sormunen R, Kallioinen M, Karvonen J (1993) The first Orf virus epidemic diagnosed in man and reindeer in 1992-1993 in Finland (in Finnish). Duodecim. 109 1945-1950... 

Mercury is a very useful chemical, and if handled properly, can be used routinely without fear. There is no need to shut down a laboratory because of a mercury spill. Clean it up immediately and continue. However, if spillage is not cleaned up, the vapors can cause chronic metal poisoning after prolonged exposure (Table 6-2). An extreme example is the old-time Hatter s disease. This occurred when hat makers treated beaver fur with HgfNOj), to permit the fiir to kink into felt. After continued exposure, the hatters often got the shakes. Anyone who shook was mad as a hatter. Mereurous compounds are much less soluble than mercuric compounds. In fact, a spoonful of calomel (Hg2Cl2) often was given... 

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