Differential Diagnosis for Lower Extremity Edema
Single Most Likely Diagnosis
- Immobilization-induced venous thromboembolism (VTE): The patient's recent two-week hospital stay for stroke, which likely involved prolonged immobilization, increases the risk for developing venous thromboembolism, including deep vein thrombosis (DVT). The presence of SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion) could further complicate fluid balance, but immobilization is a strong risk factor for VTE.
Other Likely Diagnoses
- Heart failure: Especially if the stroke was cardioembolic or if there's a history of heart disease, heart failure could lead to fluid overload and edema.
- Nephrotic syndrome or renal failure: Although less directly related to the recent hospital stay, kidney issues could arise from various causes, including medications or the stroke itself affecting renal function, leading to edema.
- Hypervolemia due to SIADH: While SIADH primarily affects water balance, it can lead to a state of hypervolemia, contributing to edema, especially in the context of decreased mobility and potential cardiac strain from the stroke.
Do Not Miss Diagnoses
- Cellulitis or infectious cause: Infection can cause localized edema and must be considered, especially if there are signs of infection such as redness, warmth, or fever.
- Deep vein thrombosis (DVT) with pulmonary embolism risk: As mentioned, DVT is a significant concern, but it's crucial to also consider the risk of pulmonary embolism, which can be life-threatening.
- Lymphatic obstruction: Though less common, any process that obstructs lymphatic drainage (e.g., tumor, surgical complication) could lead to edema.
Rare Diagnoses
- Lymphedema: This could be a consideration if the edema is unilateral and there's a history of surgery, radiation, or other causes of lymphatic damage.
- Thyroid disorders: Both hypothyroidism and hyperthyroidism can cause edema, though this would be less directly related to the recent hospital stay and stroke.
- Sarcoidosis or other granulomatous diseases: These conditions can cause lymphadenopathy and, rarely, lymphatic obstruction leading to edema, but they would be unusual causes in this context.
- Fabry disease or other lipid storage diseases: Extremely rare causes of edema due to systemic involvement affecting the vascular endothelium or renal function.