Stemmer Sign: Diagnosis and Clinical Application
The Stemmer sign is a physical examination finding used to diagnose lymphedema, characterized by the examiner's inability to pinch and lift the skin fold at the base of the second toe or finger on the affected limb compared to the contralateral side. 1
Clinical Technique and Interpretation
The test is performed by attempting to pinch the skin of the dorsum of the foot (at the base of the second toe) or hand (at the base of the second finger)—a positive Stemmer sign occurs when the examiner cannot lift the thickened skin fold, indicating fluid accumulation due to lymphedema. 1
The sign reflects abnormal accumulation of interstitial fluid and fibroadipose tissue resulting from injury, infection, or congenital abnormalities of the lymphatic system. 1
Diagnostic Performance
Sensitivity and Specificity
A positive Stemmer sign demonstrates high sensitivity (92%) for detecting lymphedema confirmed by lymphoscintigraphy, making it a useful screening tool. 2
However, the test exhibits only moderate specificity (57%), meaning negative results do not reliably exclude lymphedema. 2
Overall diagnostic accuracy of clinical signs including Stemmer sign is approximately 47%, with sensitivity of only 17% and specificity of 88% when evaluating all clinical signs collectively. 3
Predictive Value
Of all clinical signs for lymphedema (dorsal hump, square toes, Stemmer sign, nonpitting edema), only the Kaposi-Stemmer sign is a significant independent predictor of lymphoscintigraphy-confirmed lymphedema (odds ratio 7.9). 3
Among patients with positive clinical signs, only 68% actually have lymphedema confirmed by lymphoscintigraphy—the remaining 32% have normal lymphatic function. 3
Common Pitfalls and False Results
False-Positive Results
Obesity is the most common cause of false-positive Stemmer sign—thickened skin folds in obese patients can mimic lymphedema without actual lymphatic dysfunction. 1, 2
Other causes of false-positive results include spinal muscle atrophy and venous obstruction, which is the most common cause of swelling in patients with positive clinical signs but normal lymphoscintigraphy. 2, 3
False-Negative Results
Patients with false-negative Stemmer sign (positive lymphedema but negative test) are more likely to have normal body mass index and early Stage 1 disease. 2
Among 258 limbs with lymphoscintigraphy-confirmed lymphedema, only 17% demonstrated positive clinical signs, highlighting the poor sensitivity of clinical examination alone. 3
Differential Diagnosis
The first critical step is distinguishing edema from lymphedema—lymphedema is most commonly unilateral, while bilateral swelling suggests cardiac, renal, or hepatic causes of increased hydrostatic pressure or decreased oncotic pressure. 1
When lymphedema is excluded by negative Stemmer sign, consider: cardiac causes (heart failure, valvular disease, pericardial disease), cirrhosis with portal hypertension, renal failure, and venous obstruction. 1, 3
A history of lymph node dissection, radiation therapy, infection, or congenital abnormalities increases pre-test probability for lymphedema. 1
Clinical Management Algorithm
When Stemmer Sign is Positive
Proceed with lymphoscintigraphy to objectively confirm lymphedema diagnosis before committing patients to lifelong conservative therapy, as one-third of patients with positive clinical signs have normal lymphatic function. 3
If lymphoscintigraphy confirms lymphedema, initiate appropriate conservative management including compression therapy and manual lymphatic drainage. 1
If lymphoscintigraphy is normal despite positive Stemmer sign, evaluate for venous obstruction as the most likely alternative diagnosis. 3
When Stemmer Sign is Negative
In patients with high clinical suspicion for lymphedema but negative Stemmer sign, lymphoscintigraphy should be performed, as 10 of 23 patients (43%) with negative Stemmer sign had abnormal lymphatic function on imaging. 2
This is particularly important in patients with normal BMI and early-stage disease, who are most likely to have false-negative results. 2
Routine use of lymphoscintigraphy is recommended to make an objective diagnosis rather than relying on clinical signs alone. 3
Key Clinical Considerations
Despite being highly sensitive, the Stemmer sign should not be used as the sole diagnostic criterion—it is a supplementary clinical finding that requires objective confirmation with lymphoscintigraphy in most cases. 2, 3
The test is most useful as a screening tool when positive in non-obese patients, but its moderate specificity and poor negative predictive value limit its utility for ruling out disease. 2, 3
Patients with positive clinical signs but normal findings on lymphoscintigraphy who lack medical causes for swelling should undergo workup for venous causes of edema. 3