Registered Nurse (RN) Endocrine Licensure Exam

A patient presents with protruding eyeballs and pretibial myxedema. What is the likely cause of these symptoms?

1. Thyroiditis

2. Deficiency of iodine consumption

3. Grave's Disease

4. Hypothyroidism

The correct answer is: Grave's Disease

The presence of protruding eyeballs, known as exophthalmos, along with pretibial myxedema, strongly indicates Graves' disease. This condition is an autoimmune disorder that leads to hyperthyroidism and is characterized by the overproduction of thyroid hormones. The autoimmune response not only results in an increased metabolic rate but also triggers the characteristic changes seen in the eyes and skin. In Graves' disease, the immune system produces antibodies that stimulate the thyroid gland, causing it to enlarge and produce excess hormones. The antibodies can also affect the eye muscles and orbital tissues, leading to the inflammation and swelling that causes the eyes to protrude. Additionally, the deposition of glycosaminoglycans in the pretibial area leads to the thickening of the skin, known as pretibial myxedema, which is another hallmark of this condition. While thyroiditis involves inflammation of the thyroid gland, it does not typically present with the specific combination of symptoms seen here. A deficiency of iodine consumption leads to hypothyroidism and can cause goiter, but it is not associated with exophthalmos or pretibial myxedema. Lastly, hypothyroidism is characterized by low levels of thyroid hormones and would not explain the symptoms of hyper