Non-obese lipedema patients show a distinctly altered quantitative sensory testing profile with high diagnostic potential

Lipohyperplasia dolorosa (LiDo), also known as lipedema, is a painful subcutaneous adipose tissue disorder. While the characteristic bilateral accumulation of adipocytes in extremities sparing hands and feet is investigated, an objective characterization of pain and the sensory system of LiDo patients is missing. Accordingly, progress to overcome the unsatisfying response to pain-therapeutics of patients of this widespread, lifelong, and severe disease is missing. We characterized the sensory detection profile of painful and non-painful stimuli in 20 non-obese LiDo patients and 20 waist-to-height-ratio matched controls using the clinically approved QST-protocol of the German Research Association on Neuropathic Pain (DFNS e.V.). Further, pain-reports and participants’-psychometry was assessed using the German Pain Questionnaire. LiDo patients showed no overt psychometric abnormalities. LiDo pain appeared as somatic rather than neuropathic or psychosomatic aversive. All QST measurements were normal with the selective exception of two: The pressure pain threshold (PPT) was strongly reduced and the vibration detection threshold (VDT) was strongly increased selectively at the affected thigh. In contrast, sensory profiles at the dorsum of the hand were normal. ROC-analysis of the combination of PPT and VDT of thigh versus hand shows high sensitivity and specificity, categorizing correctly 96.5% of the measured participants as LiDo patients or healthy controls, respectively. Thus, we propose to assess both, PPT and VDT, at the painful thigh and the pain-free hand as basis to develop a combined PVTH-score for differential diagnosis as a fast and convenient bedside test for the identification of non-obese LiDo patients.