Case study:

Tyrotoxicosis

Patient's history:

37 yr-old woman

P/C : unintentional weight loss

HoPC :

• over past 3 months - lost appx 15 lb w/o changing her diet / activity level
• feels great
• excellent appetite
• no GI complaints - except occasional loose stool
• good energy level
• no fatigue
• no heat / cold intolerance

O/E :

• HR 108 bpm
• BP 142/82 mmHg
• afebrile
• stare-looking, protuberant eye
• large, smooth, non-tender thyroid gland
• 2/6 systolic ejection murmur
• skin warm and dry
• no tremor

1)most likely diagnosis:

• Thyrotoxicosis / Graves Disease

2) how to confirm?

• TSH - serum low
• free T4 - increased
• clinical presentation
• OTHER TESTS : thyroid-stimulating immunoglobulin / diffusely elevated uptake of radioactive iodine on thyroid scan

3)tx options

• anti-thyroid drugs
• radioactive iodine ablation
• surgical ablation of thyroid

Clinical approach

Cardiac : long standing thyrotoxicosis can cause cardiomegaly

GI : hyperdefecation - increased GI motility

Eyes : retraction of upper eyelid - increased of sympathetic tone

Skin : warm, moist, velvety. sweating - vasodilation and heat dissipation

reproduction : oligomenorrhea (infrequent menstruation), impotence, gynaecomastia

metabolism: weight loss, preference for cold temperature

Etiology: Graves disease

• most common cause of hyperthyroidism
• women
• 30-50 yr old
• autoimmune disease
• autoantibodies that activate TSH receptor of thyroid follicular cells
• autoantibodies - cross placenta and can cause neonatal thyrotoxicosis

other causes of thyrotoxicosis:

• toxic multinodular goiter
• autonomous hyperfunctioning adenoma (hot nodule)
• increased uptake (hot)
• thyroiditis
• medications : exogenous thyroid hormones
  

clinical:

• goiter (enlarged thyroid gland)
• thyroid bruit
• hyperthyroidism
• ophthalmopathy
• inflammation of extraocular muscle, orbital fat, and connective tissue - proptosis. periorbital edema
  
• dermopathy
• raised hyperpigmented orange peel texture papules
• common site : shin - pretibial myxedema

Tx:

• meds
• beta-blockers (for symptoms relief)
• antithyroid drugs (methimazole , propylthiouracil)
• decreasing production of thyroid hormone
• short term, prior to radioactive treatment
• long term treatment
• SE : rash, allergic reactions, arthritis, hepatitis, agranulocytosis
• radioactive iodine (treatment of choice)
• C/I pregnancy, women of child-bearing age
• graves ophthalmopathy exacerbated by radioactive, may use glucocorticoid
• Surgery
• reserved for large goiter (if obstructive symptoms)