[Iodine-induced hyperthyroidism in the aged. 2. Pathomechanism, differential diagnosis and therapy problems].

The occurrence of multiple processes in elderly patients brings a high risk for diagnostic or therapeutic induced iodine-hyperthyroidism. Often an atypical form of hyperthyroidism without classical symptoms is induced. The cause of iodine-induced hyperthyroidism exists mostly in autonomous tissue beyond a "critical volume" in localized or disseminated form. If the deficiency of iodine in endemic goitre areas is substituted by iodine-application, hypermetabolism of autonomous tissue causes hyperthyroidism. The pathomechanism of autonomy and iodine-induced hyperthyroidism is not completely known. General iodine salt prophylaxis will bring less amounts of autonomous goitres. Some differential diagnostic possibilities for avoiding iodine-contamination in the elderly patients and therapeutic consequences after unavoidable iodine-application are described.