Learning to diagnose lymphedema properly can be challenging, as many training programs lack knowledge and exposure to lymphedema patients. Unfortunately, there is no single standard official diagnostic criteria for determining if someone has lymphedema. This becomes even more complicated for patients with primary lymphedema, where the symptoms may have been present since birth or have been around for years and gradually worsened.
There are some diagnostic or imaging tests that can be performed to help with diagnosis, however, a physical exam and thorough history of symptoms are typically the key parts of diagnosis and most experts use history and physical examination alone to make the diagnosis.
Imaging technologies such MRI, CT, or ultrasounds can be used to see if there is a collection of extracellular fluid in the tissue. Bio-impedance spectroscopy looks at how the tissue conducts a small, imperceptible electrical current and can also be used to detect extracellular fluid. Bio-impedance can also be used to detect patients in Stage 0 Subclinical phase, when their physical exam will be unremarkable but when the condition is highly reversible. Lymphoscintigraphy is a type of imaging done at some centers that uses nuclear medicine to see lymph vessels and lymph nodes. It can show if your lymphatic system has any abnormalities in lymph flow or structure.
Diagnosis of Lymphedema
Most experts rely on a good history and physical exam to diagnosis lymphedema. Of all the clinical findings, many experts rely heavily on use of the Kaposi-Stemmer’s sign. This test measures the ability of a clinician to lift and tent tissue. A positive Stemmer’s sign is diagnostic of lymphedema. It is classically measured at the base of the toes in the foot for patients with lower extremity swelling. It can be measured anywhere in the body where lymphedema is suspected. If you can gently pinch and can tent the tissue (bring the skin folds together), then the Stemmer’s sign is negative. If you cannot gently pinch and tent the tissue, this is because the protein rich lymph fluid in the tissues prevents you from bringing the skin folds together and the Stemmer’s sign is positive. A positive Stemmer’s sign is diagnostic of lymphedema. In Figure 1, notice that the clinician is not able to bring the skin folds together, so the Stemmer’s sign is positive, and this patient has a diagnosis of lymphedema.
