[Iatrogenic thyroid pathology].

A physiological dose of iodine is necessary for thyroid hormonogenesis, but in pharmacological dosage it is a danger. Massive intakes of iodine, always of medical origin (radiodiagnosis, therapeutic) trigger off a defence mechanism in the thyroid gland, called Wolff-Chaikoff effect. This useful mechanism may be defective and abnormalities of thyroid function may appear either in the form of hypothyroidsm with goitre or temporary hyperthyroidism. The increasing use of drugs containg iodine and certain specially noxious substances such as amiodarone in particular give this iatrogenic thyroid pathology a new dimension, for it is no longer seen only by the specialist but also by the general practitioner. It involves the doctor's reponsibility not only in diagnosis but also in treatment.