A 32-year-old woman presents to the clinic with complaints of weight loss, increased appetite, and fatigue over the past three months. She reports feeling anxious and irritable, and her family has noticed her being unusually emotional. She describes frequent heart palpitations and a sensation of her heart “racing” even while at rest. Additionally, she has been experiencing heat intolerance, excessive sweating, and muscle weakness, particularly in her thighs. Her menstrual periods have become irregular, and she notes frequent bowel movements but no diarrhea. She denies any recent illness or travel. On further questioning, the patient mentions that her eyes have felt irritated, and her vision seems slightly blurred. She has also noticed swelling around her neck that she thought might be related to weight changes. Her medical history is unremarkable except for a family history of thyroid disorders, as her mother was treated for hyperthyroidism in her 40s. She is not on any medications and does not smoke or drink alcohol. On examination, the patient appears anxious and restless. Her vital signs reveal a heart rate of 112 beats per minute, blood pressure of 130/78 mmHg, and a fine resting tremor in both hands. She has a noticeable goiter, which is soft and diffusely enlarged without nodules. Her skin is warm and moist. Examination of the eyes reveals bilateral proptosis with mild periorbital edema and lid retraction. Deep tendon reflexes are brisk, and she has mild proximal muscle weakness in her legs.Thyroid function tests show suppressed TSH (<0.01 µIU/mL) with elevated free T4 and T3 levels. Thyroid-stimulating immunoglobulin (TSI) is positive. A thyroid ultrasound demonstrates diffuse enlargement of the gland without discrete nodules. Radioactive iodine uptake scan reveals increased, homogenous uptake. Which of the following dermatologic signs is also characteristic of this disorder?
