By Robyn Bjork, MPT, CWS, WCC, CLT-LANA

In a busy wound clinic, quick and accurate differential diagnosis of edema is essential to appropriate treatment or referral for comprehensive care. According to a 2010 article in American Family Physician, 80% of lower extremity ulcers result from chronic venous insufficiency (CVI). In 2007, the German Bonn Vein Study found 100% of participants with active venous ulcers also had a positive Stemmer’s sign, indicating lymphedema.

Lymphedema secondary to CVI is called phlebolymphedema (“phlebo” means veins). Whereas CVI warrants compression therapy alone, phlebolymph-edema may require complete decongestive physiotherapy. To provide optimal care, a wound care clinician must differentiate between CVI and phlebolymphedema. Fortunately, differential diagnosis can be made in 10 seconds or less by performing Stemmer’s test.

How to perform Stemmer’s test

Stemmer’s test results in either a positive or negative sign for lymphedema. To perform it, try to pinch and lift a skinfold at the base of the second toe or middle finger. If you can pinch and lift the skin, Stemmer’s sign is negative. If you can’t, the sign is positive. False positives never occur. On the other hand, a negative test doesn’t rule out lymphedema.

Stemmer’s test is diagnostic for phlebolymphedema or any other form of lymphedema. Not all wound-care clinicians need to determine the type or underlying causes of lymphedema. A positive Stemmer’s sign means the patient has lymphedema and should be referred for further evaluation and treatment by a lymphedema specialist.

Understanding the pathophysiology behind the test

A 10-second test might seem too good to be true. Also, how can Stemmer’s sign never be falsely positive? The answers lie in understanding the pathophysiology behind the test.

The primary function of the lymphatic system is to recycle blood proteins. Half of plasma proteins leak into the interstitial space and are recovered by the lymphatic system each day. Think of them as delivery men carrying nutrients to cells. They deliver their packages and go back into the bloodstream via the lymphatics to make more deliveries. But when the lymphatic system is blocked or damaged, proteins accumulate in the tissues. This causes the pathologic changes that lead to a positive Stemmer’s sign.

Like butter turning rancid, proteins accumulating in the tissues become denatured; macrophages migrate to the area to digest them. In what resembles the wound-healing process, macrophages release interleukin 1, which activates fibroblasts to produce collagen. This normal cascade becomes pathologic as excessive collagen is produced and denatured proteins trigger chronic inflammation. This process causes thickened, dense, fibrotic skin.

Typically, chronic lymphedema progresses from the toes or fingers proximally. The thin skin of the dorsum of the foot or hand is the first area to show signs of thickening, which leads to a positive Stemmer’s sign. (See Positive Stemmer’s sign by clicking the PDF icon above.)

Clinical considerations and test modifications

Unlike protein-rich lymphedema, edema in a patient with CVI or congestive heart failure (CHF) is watery. Proteins continue to circulate through the lymphatic system and don’t accumulate in tissues. If your patient has only CVI, no swelling occurs in the toes, and Stemmer’s sign is negative. Hemosiderin staining, the classic sign of CVI, likely will occur in the lower legs. (See Negative Stemmer’s sign in a patient with CVI by clicking the PDF icon above.)

In contrast, a patient with CHF has swelling of the toes and dorsum of the foot. In this case, when performing the Stemmer’s test, allow sufficient time for pitting edema to displace. Then note skin texture and try to pinch a skinfold. Edema solely from CHF displaces slowly, and Stemmer’s sign is negative. If the sign is positive, it means the patient has both CHF and lymphedema.

What happens in phlebolymphedema

Phlebolymphedema refers to lymphedema caused by CVI—a disorder that leads to valvular failure of the veins and increased tissue edema. Normally, as skin stretches from edema, elastic fibers pull open the lymphatic capillaries via their attachments by anchoring filaments. However, extreme distention causes rupture of these filaments and shredding of lymphatic capillary walls. What’s more, lymphatic overloading to compensate for venous insufficiency can lead to valvular failure of lymphatic vessels. As lymphedema progresses, the skin thickens and becomes lumpy, and wartlike knobs or projections may develop. Called papillomatosis, this condition indicates advanced lymphedema. (See Phlebolymphedema.)

Sometimes localized lymphatic damage occurs, with skin changes arising only in affected areas such as periwound tissues. In this case, you can modify Stemmer’s test by assessing skin texture in affected areas.

Understanding localized periwound lymphedema and its treatment aids healing of chronic wounds. White blood cells use lymphatics to drag bacteria and toxins to lymph nodes, in turn triggering an immune response. As wound care clinicians, we are acutely aware of bacterial bioburden and its negative effect on wound healing. Without a continuous flow of lymph, the body’s natural ability to fight bacteria is compromised. Further, debris, dead cells, and other byproducts of wound healing—normally removed via the lymphatics—cause stagnation of the wound environment and slow wound healing.

What a negative sign may mean

As mentioned, a negative Stemmer’s sign doesn’t rule out lymphedema. For example, a malignant tumor may cause lymphedema proximally in a limb; because lymphedema onset is acute and swelling is worse proximally, Stemmer’s sign may be negative.

Useful screening tool

Stemmer’s sign is a useful tool for screening patients in the wound clinic and promotes recognition of many lymphedema cases that otherwise might go undiagnosed and untreated. (See Clinical wisdom: Stemmer’s sign by clicking the PDF icon above.) Remember that patients with CVI and chronic venous ulcers have a high prevalence of secondary lymphedema. Also keep in mind that while a positive Stemmer’s sign always indicates lymphedema, a negative test doesn’t exclude lymphedema. Refer lymphedema patients to a lymphedema specialist for further assessment and treatment.

Click here www.lympho.org/resources.php to download International Consensus: Best Practice for the Management of Lymphoedema.

Selected references
Brenner E, Putz D, Moriggl B. Stemmer’s (Kaposi-Stemmer-) sign—30 years later: case report and literature review. Phlebologie. 2007;36(6):320-324.

Collins L, Seraj S. Diagnosis and treatment of venous ulcers. Am Fam Physician. 2010;81(8): 989-996.

Farrow W. Phlebolymphedema–a common underdiagnosed and undertreated problem in the wound care clinic. J Am Col Certif Wound Spec. 2010;2(1):14-23.

Föeldi M. Földi’s Textbook of Lymphology: For Physicians and Lymphedema Therapists. 3rd ed. Urban & Fischer; 2012.

Lymphoedema Framework. Best Practice for the Management of Lymphoedema. International consensus. London: MEP Ltd; 2006.

Macdonald JM, Ryan TJ, eds. Lymphoedema and the chronic wound: the role of compression and other interventions. In: World Health Organization. Wound and Lymphoedema Management. 2010:63-84.

Nelzén O. Prevalence of venous leg ulcer: the importance of the data collecting method. Phlebolymphology. 2008;15(4):143-150.

O’Connell DG, O’Connell JK, Hinman MR. Special Tests of the Cardiopulmonary, Vascular, and Gastrointestinal Systems. Thorofare, NJ: Slack; 2010.

Pannier F, Hoffmann B, Stang A, Jöckel KH, Rabe E. Prevalence of Stemmer’s sign in the general population. Phlebologie. 2007;36(6):287-342.

Piller N. Phlebolymphoedema/chronic venous lymphatic insufficiency: an introduction to strategies for detection, differentiation and treatment. Phlebology. 2009;24(2):51-55.

Simonian SJ, Morgan CL, Tretbar LL, Blondeau B. Differential diagnosis of lymphedema. In: Tretbar LL, Morgan CL Lee BB, Simonian SJ, Blondeau B. Lymphedema: Diagnosis and Treatment. London: Springer-Verlag; 2008;12-20.

Photos used with permission from the International Lymphoedema Framework. The author provided the remaining photos.

Robyn Bjork is a physical therapist, certified wound specialist, and certified lymphedema therapist. She is also chief executive officer of the International Lymphedema and Wound Care Training Institute, a clinical instructor, and an international podoconiosis specialist.