Which sign is most specific for Graves disease?

• A. Cold intolerance
• B. Exophthalmos
• C. Lid lag
• D. Hyperreflexia

Answer: (B)

Exophthalmos is most specific for Graves disease because it reflects autoimmune inflammation and edema of the orbit driven by TSH receptor antibodies. This orbital involvement—proptosis with eyelid retraction and periorbital swelling—is a hallmark feature strongly associated with Graves and is not commonly seen in other causes of thyrotoxicosis.

Other signs described—cold intolerance, lid lag, and hyperreflexia—can occur with thyrotoxicosis from various causes and are not unique to Graves. Cold intolerance is a nonspecific symptom of thyroid dysfunction, lid lag can accompany thyrotoxicosis generally, and hyperreflexia reflects increased metabolic activity but isn’t exclusive to Graves.