Graves disease and its extrathyroidal signs

How it presents

The general features of Graves disease are heat intolerance, weight loss and sweating. The eyes show lid lag, proptosis and diplopia. The skin shows hair loss and infiltrative dermopathy, that is pretibial myxedema. The cardiovascular features are tachycardia, hypertension and atrial fibrillation, and the nails show onycholysis and clubbing, called acropachy. The endocrine features are hyperglycemia, hypercalcemia, bone loss and menstrual irregularities; the gut shows diarrhea; the neurology shows tremors, hyperreflexia and proximal muscle weakness, with increased DTR. On examination there is a palpable midline neck mass moving with swallowing over which a bruit is auscultated. The mass moves with swallowing because the pretracheal fascia encloses the thyroid and gets attached to the hyoid, because the ligament of Berry, a thickened pretracheal fascia, is attached postero medially above to the cricoid cartilage, and because the isthmus has some attachment with the trachea directly.

The extrathyroidal signs are what name the disease. Exophthalmos, that is proptosis, is most likely Graves disease, and pretibial myxoedema is seen in Graves disease. Exophthalmos refers to protrusion of the eyeball due to endocrine causes, mainly thyroid eye disease, Graves' orbitopathy, and is usually bilateral, with lid retraction, conjunctival injection and restrictive strabismus as associated signs. Proptosis is the broader term for any forward displacement of the eye regardless of the cause, such as orbital tumors, trauma, infection or inflammation like orbital cellulitis and retrobulbar hemorrhage, and may be unilateral or bilateral. The key takeaway is that exophthalmos is proptosis from thyroid disease. Periorbital edema with exophthalmos is Graves' ophthalmopathy, and acropachy and proximal myopathy are the other extrathyroidal signs.