Thyroid Diseases Flashcards
Most physiologic marker of thyroid hormone action
TSH
Major POSITIVE regulator of TSH
Thyrotropin Releasing Hormone (TRH)
May artificially SUPPRESS TSH
Thyrotoxicosis
hCG secretion in early pregnancy
High dose GC therapy
Treatment with dopamine
Critical first step in the synthesis of thyroid hormone
Uptake of iodide
Mental and growth retardation in children due to severe iodine deficiency
Cretinism
Autosomal recessive disorder characterized by goiter and sensorineural deafness caused by DEFECTIVE ORGANIFICATION of iodine
Pendred Syndrome
May raise serum Total T4 and T3 levels by causing elevation of serum thyroxine binding globulin (TBG)
Estrogen
Characteristic distinguishing T4 from T3
100% produced directly from the thyroid
Transient inhibition of thyroid iodide organification in response to excess iodide
Wolff-Chaikoff phenomenon
Venous distention over the neck and difficulty breathing upon raising the arms caused by large retrosternal goiters
Pemberton sign
Lid lag that occurs with exophthalmos in thyrotoxicosis
Von Graffe sign
Condition in which finding a bruit over the thyroid gland indicates increased vascularity
Hyperthyroidism
Thyrotoxic states characterized by a LOW or ABSENT radioactive iodine uptake
Thyrotoxicosis factitia
Subacute thyroiditis
MC cause of hypothyroidism worldwide
Iodine Deficiency
Associated with Hashimoto’s Thyroiditis
Autoimmune Hypothyroidism
Associated with Autoimmune Hypothyroidism
Vitiligo Type 1 DM Pernicious Anemia Addison’s Disease Alopecia areata
Cause of myxedema with typical non-pitting skin thickening
Increased dermal glycosaminoglycan content
Can establish autoimmune etiology for clinical or subclinical hypothyroidism
Presence of thyroid peroxidase (TPO) antibodies
Low or normal TSH + Low unbound T4 + Clinical signs of hypothyroidism
Hypopituitarism
Masked thyrotoxic features in the elderly, with patients presenting mainly with fatigue, depression and weight loss
Apathetic thyrotoxicosis
MC cardiovascular manifestation of Grave’s disease
Sinus Tachycardia
Indurated plaque-like lesions with an “orange skin” appearance on the anterior or lateral aspects of the lower legs seen in thyrotoxicosis
Pretibial myxedema
“Thyroid acropachy”
Clubbing
Pt with Normal FT4 + very low TSH and with suspected thyrotoxicosis, what should be the next diagnostic test?
FT3 determination
Clinical SSx of thyrotoxicosis + Normal or increased TSH + Increased FT4
Pituitary Adenoma
Anthithyroid of choice for Grave’s disease during pregnancy
PTU