Question

A ten year old boy presents to the pediatric emergency unit with seizures. Blood pressure in the upper extremity is measured as 200/140 mm Hg. Femoral pulses are not palpable. The most likely diagnosis amongst the following is:

• A. Takayasu aortoarteritis
• B. Renal parenchymal disease
• C. Grand mal seizures
• D. Coarctation of aorta

Hint:

High arm BP plus absent femoral pulses equals a narrowed aorta.

Answer 1

The Correct Option is D

Step 1: Pick out the two strong clues. There is very high blood pressure in the arms (200/140) and the femoral pulses are absent. This combination of upper-limb hypertension with weak or absent lower-limb pulses points to a fixed narrowing of the aorta beyond the arm vessels.
Step 2: Coarctation of the aorta is a congenital narrowing just past the left subclavian artery. Blood pressure is high in the arms but low in the legs, so femoral pulses are weak, delayed or absent. A hypertensive crisis can cause the seizure. This fits the picture exactly.
Step 3: Why the others are less likely. Takayasu arteritis can also cause pulseless limbs and hypertension, but it usually affects young adult women and many vessels, and it is far less likely than coarctation as the classic exam answer for a child with this exact triad. Renal parenchymal disease causes hypertension but does not by itself abolish the femoral pulses. Grand mal seizure is just a description of the fit, not a cause of the absent femoral pulses or the marked blood pressure gradient.
Step 4: The diagnosis that ties together arm hypertension, absent femoral pulses and seizures in a child is coarctation of the aorta.
Answer: Option D, Coarctation of aorta.