Peripheral Edema - Differential Diagnosis Framework for Lower Extremity Edema



Edema occurs when any of the following conditions exist:

(1) Increased capillary hydrostatic pressure

(2) Increased plasma volume

(3) Decreased plasma oncotic pressure (hypoalbuminemia)

(4) Increased capillary permeability

(5) Lymphatic obstruction



Unilateral Lower Extremity Edema:

 • DVT

 • CHF

 • Cellulitis

 • Venous insufficiency

 • Varicose veins

 • May-Thurner Syndrome

 • Complex regional pain syndrome type 1 (reflex sympathetic dystrophy)

 • Compartment syndrome

 • Lymphedema (Non-pitting)

 • Neoplasm



Bilateral Lower Extremity Edema:

 • CHF

 • Cirrhosis

 • Nephrotic Syndrome

 • SVC syndrome

 • DVT: Bilateral

 • Protein-losing enteropathy

 • Venous insufficiency

 • Medications

 • Preeclampsia

 • Lipema

 • Capillary leak syndrome

 • Lymphedema (Non-pitting)

 • Pre-tibial Myxedema; (Non-pitting)

 • Allergic reaction, urticaria, and angioedema



Note:

 • Left leg often swells first, stays slightly more swollen and the edema resolves after the right leg with diuresis

 • This is due to the compression of the left iliac vein which crosses under the right common iliac artery anteriorly causing compression/stasis.



by Dr. Ravi Singh @rav7ks and Dr. Zaven Sargsyan @sargsyanz



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