Question

on examination of a young adult patient it is noted that the upper part of the body appears pink while the lower part of the body appears pales. it is found that there is a delay between the brachial and the femoral pulses and that the blood pressure taken on the femoral artery is significantly lower than that taken on the brachial artery. on radiological examination of the chest it is found that the ribs show the presence of
otching\. what is the likely diagnosis in this case?
syphilitic aneurysm
post - ductal coarctation of the aorta
cystic medial necrosis
pre - ductal coarctation of the aorta

Explanation:

• Syphilitic aneurysm: Usually presents with different symptoms like pain, mass effect, etc., not the described upper - lower body color and pulse/blood pressure differences.
• Post - ductal coarctation of the aorta: In post - ductal coarctation, blood flow to the lower body is restricted. This leads to upper body (supplied before the coarctation site) being well - perfused (pink) and lower body (supplied after the coarctation site) being less perfused (pale). There is a delay in femoral pulse (as blood has to find collateral routes) and lower femoral blood pressure compared to brachial. Rib notching is due to collateral blood flow (intercostal arteries) eroding the ribs.
• Cystic medial necrosis: Associated with conditions like Marfan syndrome, mainly causes aortic dissection - related symptoms, not the described peripheral vascular symptoms.
• Pre - ductal coarctation of the aorta: In pre - ductal coarctation (coarctation before the ductus arteriosus), in neonates, if the ductus closes, there can be severe lower body hypoperfusion. But in older children/adults (if the ductus remains patent in some form), the presentation is different from the "classical" upper - lower body perfusion difference as described here.

Answer:

Post - ductal coarctation of the aorta