Among the connective tissue changes induced by the chronic use of anticonvulsants, gingival hyperplasia associated with the use of phenytoin is the most reliably proven. In addition it is probable that phenytoin can also lead to a coarsening of the facies. Phenobarbital can probably trigger the development of Dupuytren's contracture, polyfibromatosis and/or Sudeck's syndrome. In connection with, or independently of this, phenobarbital can also lead to painful joints. A number of anticonvulsants are suspected of being able to trigger lupus erythematodes.