Which physical examination finding is most consistent with hypothyroidism in a patient with elevated TSH and low free T4?

• A. Brittle fingernails
• B. Ophthalmopathy
• C. Pitting edema
• D. Skin hyperpigmentation

Answer: (A)

In primary hypothyroidism, the body's metabolic activity slows, and this affects the skin and its appendages. Brittle fingernails arise from reduced protein synthesis and slower turnover of keratin, which is a common exam finding when thyroid hormone levels are low despite a high TSH. This aligns with elevated TSH and low free T4, indicating underactivity of the thyroid.

Ophthalmopathy is characteristic of Graves disease, a hyperthyroid condition driven by autoimmune stimulation of the TSH receptor, not hypothyroidism. Pitting edema is not typical in hypothyroidism; the edema of myxedema is usually nonpitting due to mucopolysaccharide deposition in the interstitial spaces. Skin hyperpigmentation is not a classic feature of hypothyroidism and more often points to other endocrine disorders, such as adrenal insufficiency.

So brittle fingernails best reflect the slowed metabolic state of hypothyroidism in this context.