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Difficulty: EasyEndocrinology and Metabolism

Match each classic physical examination finding to the endocrine condition with which it is most commonly associated.

  • Pretibial myxedema (non-pitting edema of the lower extremities)Graves disease
  • Facial muscle spasm upon tapping the cheek (Chvostek sign)Hypocalcemia (e.g., Hypoparathyroidism)
  • Violaceous abdominal striae greater than 1 cm in widthCushing syndrome
  • Hyperpigmentation of the palmar creases and oral mucosaPrimary adrenal insufficiency (Addison disease)

Answer

Pretibial myxedema pairs with Graves disease; the Chvostek sign pairs with Hypocalcemia; violaceous abdominal striae pair with Cushing syndrome; and hyperpigmentation pairs with Primary adrenal insufficiency.
Each physical finding is highly specific to its respective endocrine disorder's underlying pathophysiology. Pretibial myxedema is a localized autoimmune phenomenon unique to Graves disease. The Chvostek sign reflects the classic neuromuscular excitability seen in hypocalcemia. Violaceous striae arise from hypercortisolism-induced catabolism in Cushing syndrome. Diffuse hyperpigmentation is a direct result of elevated ACTH/MSH seen specifically in primary adrenal insufficiency.

Step-by-Step Solution

1
Analyze the dermatologic finding of pretibial myxedema.
Identify it as a unique autoimmune manifestation.
It is mediated by TSH receptor antibodies stimulating dermal fibroblasts, uniquely linking it to Graves disease.
2
Evaluate the neuromuscular finding (Chvostek sign).
Identify it as a sign of membrane instability.
Low extracellular calcium directly increases the resting membrane potential of nerves, causing twitching upon mechanical stimulation.
3
Assess the origin of wide, violaceous striae.
Identify it as a sign of connective tissue breakdown.
Excess glucocorticoids (Cushing syndrome) weaken collagen and cause skin thinning, exposing underlying vascular beds.
4
Determine the cause of mucosal and palmar hyperpigmentation.
Identify it as a sign of elevated pro-opiomelanocortin (POMC) cleavage products.
Primary adrenal insufficiency lacks cortisol, resulting in high ACTH and MSH levels that stimulate melanocytes.

Key Concept

Classic physical examination findings and their associated endocrine disorders.
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Topics

Endocrinology and Metabolism

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