A 68-year-old patient presents with erythematous, scaly patc…
A 68-year-old patient presents with erythematous, scaly patches and hyperpigmentation on the lower legs, accompanied by pitting edema and chronic swelling. The skin changes are warm, mildly itchy, and located above the medial malleolus. These findings are most consistent with stasis dermatitis. What is the primary underlying pathophysiologic mechanism driving this condition?