A swollen, painful limb with cyanotic discoloration is suspicious for which condition?

The situation described involves a swollen and painful limb accompanied by cyanotic discoloration, which suggests significant vascular compromise. Phlegmasia cerulea dolens is a severe form of deep vein thrombosis that leads to dramatic swelling, pain, and a characteristic cyanotic appearance due to extensive venous obstruction. This condition can arise when a thrombosis occurs in both the deep and superficial veins, obstructing venous return.

In this context, the severe symptoms of swelling, pain, and the distinctive bluish discoloration highlight the life-threatening nature of phlegmasia cerulea dolens, which requires immediate medical attention. Other conditions listed may cause swelling and pain, but they do not typically present with the same acute cyanosis or severity associated with this specific form of venous obstruction.