Hypothyroidism

UG CLASS

1. Hypothyroidism

2. Terms Adult hypothyroidism Myxoedema Cretinism

3. Cretinism Fetal or infantile hypothyroidism Endemic and sporadic Sporadic –agenesis ,dyshormonogenesis Hoarse cry , macroglossia , umbilical hernia Immediate diagnosis and treatment

4. Adult type • bradycardia • cold extremities • dry skin and hair • periorbital puffiness • hoarse voice • bradykinesis , slow movements • delayed relaxation phase of ankle jerks. The symptoms are: • tiredness • mental lethargy • cold intolerance • weight gain • constipation • menstrual disturbance • carpal tunnel syndrome.

5. Myxoedema

6. Classification of hypothyroidism Autoimmune thyroiditis ( chronic lymphocytic thyroiditis Non- goitrous : primary myxoedema Goitrous : Hashimoto’s disease

7. Classification Iatrogenic After thyroidectomy After radioiodine therapy Drug induced ( antithyroid drugs,para-aminosalicylic acid and iodides in excess)

8. Classification Dyshormonogenesis Goitrogens Secondary to pituitary or hypothalamic disease Thyroid agenesis Endemic cretinism- Often goitrous and due to iodine deficiency

9. Dyshormonogenesis Deficient enzymes Autosomal recessive Young patients , thyromegaly , euthyroid state Pendred syndrome – TPO deficiency goitre , sensorineural deafness , abnormal bony labyrinth

10. Investigations and management TFT- low T3 , T4 and high TSH High titres of TPO antibodies Oral thyroxine (0.1 to 0.2 mg/day) or triiodothyronine (20mcg tds ) Myxoedema – bolus 500mg of T4 or 10 mcg of T3 oral or IV 4-6 hourly Corticosteroids and broad spectrum antibiotics