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Lipoedema is a chronic, progressive condition characterised by disproportionate fat accumulation in the lower extremities, often misdiagnosed due to symptom overlap with obesity. Weight management is a key component of lipoedema treatment, yet the role of bariatric surgery remains unclear. This systematic review evaluates the impact of bariatric and metabolic surgery (BMS) on lipoedema symptoms, weight loss outcomes, and the need for further interventions. A systematic search of PubMed, Scopus and the Cochrane Library was conducted up to January 2025 following PRISMA guidelines. Studies reporting on patients with lipoedema (or equivalent diagnoses) who underwent BMS were included. Quality was assessed using the Joanna Briggs Institute (JBI) checklist for case reports and the National Heart, Lung and Blood Institute (NHLBI) tool for case series. Seven studies met the inclusion criteria (five case reports, two cohort studies), comprising 51 patients. All underwent BMS, primarily sleeve gastrectomy or Roux-en-Y gastric bypass. One study (n = 31) reported a significant reduction in thigh volume and weight loss comparable to controls. The remaining studies found persistent or worsened lower body disproportionality and no improvement in pain. Postoperative lipoedema diagnoses were common, raising concerns over diagnostic accuracy. Overall weight loss averaged 33.9% total weight loss. Bariatric and metabolic surgery achieves meaningful weight reduction in patients with lipoedema and obesity but does not consistently improve core lipoedema symptoms. Its role remains adjunctive rather than primary. Preoperative identification and documentation of lipoedema features are recommended, with a postoperative plan for adjunct conservative therapies and selective consideration of lymph-sparing liposuction where symptoms persist. Larger prospective studies using standardised definitions and outcome measures are needed to clarify its therapeutic value in this population.

Lipedema is a chronic disease characterized by the symmetrical accumulation of adipose tissue in the lower body, primarily affecting women. Despite being recognized for over 85 years, the pathophysiology, diagnosis, and treatment of lipedema remain complex and not fully understood. This review consolidates current knowledge, emphasizing histological, genetic, and hormonal factors, alongside diagnostic and therapeutic approaches. Histological studies highlight changes such as adipocyte hypertrophy, increased fibrosis, and vascular alterations like angiogenesis. Genetic studies suggest a strong familial component, with multiple loci potentially influencing disease onset, yet the condition remains polygenic and influenced by environmental factors. Hormonal influences, particularly estrogen, play a significant role in disease pathogenesis. Diagnostic imaging techniques like dual-energy X-ray absorptiometry (DXA), ultrasound (US), and magnetic resonance imaging (MRI) provide valuable insights but are not definitive. Therapeutic strategies, including diet, weight loss, and Complex Decongestive Therapy, offer symptom management but are not curative, with liposuction considered for severe cases where conservative methods fail. The condition's complexity stems from genetic, hormonal, and environmental influences, necessitating further research to improve diagnostic and treatment strategies. Integrating genetic and hormonal insights into clinical practice could enhance patient outcomes and quality of life, highlighting the need for continued exploration and understanding of lipedema.

Lipedema predominantly affects women and is characterized by an abnormal distribution of adipose tissue, accompanied by pain or discomfort in affected areas. Despite growing awareness, inconsistent diagnostic criteria and treatment approaches hinder medical care and research. This multi-phase Delphi study was conducted to address the need for internationally accepted consensus on fundamental aspects of the disease. Through online surveys and an in-person discussions, experts representing 19 countries evaluated on 62 original statements regarding (1) clarity, (2) agreement, (3) recommendation for inclusion, (4) strength of evidence, and (5) whether additional evidence was needed. Ultimately, 59 statements reached consensus across eight domains encompassing the definition and management of lipedema. The findings provide a framework to guide internationally applicable recommendations for patients with lipedema that may improve outcomes globally. Limited evidence in several areas highlights the importance of further research, standardization of data reporting, and international collaboration among healthcare providers, researchers, and patient advocates to address this women's health disparity effectively.

Lipedema is a multifactorial pathology with a negative evolutionary trend, in which genetic, hormonal, metabolic, and vascular factors play distinct roles that are not fully understood. Inflammation is a typical feature of lipedema and can be managed by limiting glycaemic spikes. Herein, we reported a subject diagnosed with lipedema who underwent a ketogenic diet for six months, losing 12 kg, and then transitioned to a low-carb diet for a further six months, keeping the good results obtained, in terms of quality of life improvement, weight control, and pain management with low-carb. The patient was regularly trained with resistance training, which preserved and improved muscular mass. The primary and new outcome was due to the introduction of the second phase of the nutritional plan, low-carb, which could be an innovative approach. Often, diets with regular carbohydrate amounts do not give appreciable results.

Lipedema is a chronic and progressive disorder characterized by disproportionate fat accumulation, mainly affecting the lower extremities of women, and commonly accompanied by sensations of heaviness, tenderness, and discomfort. While its pathogenesis remains largely unknown, genetic, hormonal, and microvascular factors have been implicated. The condition often coexists with psychological distress, which significantly detracts from the quality of life of affected individuals. Diagnosis is primarily clinical, as no specific biomarkers or imaging modalities have been proven sufficiently reliable for identification. Proposed managements are controversial, although current treatment focuses on symptom management and disease control through conservative methods such as compression and non-invasive device therapies, specialized diets, and physical rehabilitation or surgical treatments. Psychological support is vital in addressing the emotional challenges of the condition. Despite recent advancements in the understanding and management of lipedema, there remains a critical need for further research to establish standardized diagnostic criteria and targeted therapeutic strategies for this debilitating condition.

Lipedema is a chronic, underdiagnosed adipose disorder marked by disproportionate fat accumulation, pain, and impaired mobility. Misdiagnosis as obesity or lymphedema delays care and increases morbidity. We systematically reviewed clinical features, diagnostic criteria, and management options (conservative and surgical). A comprehensive search of the PubMed database was conducted in January 2025 for English-language articles published from January 1950 to January 2023 using the keywords "lipedema" or "lipoedema." Additional references were identified via manual review of relevant systematic reviews. Two independent reviewers screened studies and graded quality using a modified Oxford scale. Of 339 articles, 61 met the inclusion criteria. Most were observational cohorts, case series, or expert consensus, with few randomized trials. Conservative therapies, including ketogenic or Rare Adipose Disorders (RAD) diets, compression therapy, and aquatic exercise, were associated with reduced pain and swelling (Grade 2A-2B). Tumescent liposuction showed the strongest evidence for sustained symptom improvement, mobility, and quality of life (Grade 1 recommendation, evidence quality 2-3). Lipedema is a distinct, progressive condition requiring early recognition and intervention. Conservative therapies may provide partial relief, but tumescent liposuction remains the most effective treatment. Standardized diagnostic criteria, validated patient-reported outcomes, and clearer guidelines are needed to harmonize care and improve long-term outcomes.

BackgroundLipedema is a chronic disorder involving abnormal accumulation of subcutaneous fat, primarily in the lower limbs. Liposuction is an effective treatment, but postoperative complications such as fluid retention and seroma formation are common. While the use of surgical drains is well established in other areas of plastic surgery, their role in lipedema liposuction remains unclear.MethodsThis prospective observational study involved 50 consecutive patients with stage II or III lipedema who underwent lower leg liposuction. A novel passive drainage technique was used, involving glove drains fashioned from sterile, powder-free nitrile gloves and inserted through existing liposuction incisions. Drain duration, postoperative swelling, and complications, particularly seroma formation, were evaluated.ResultsAll patients completed follow-up with no major complications. Glove drains remained in place for an average of 2.4 ± 0.5 days. Only 2 patients (4%) developed seromas requiring single aspiration. No infections, hematomas, or lymphatic complications were recorded. Patients reported reduced swelling and discomfort compared to historical cases without drains.ConclusionPassive glove drains appear to be a simple, safe, and effective method to manage postoperative fluid collections after lipedema liposuction of the lower legs. The technique may lower the risk of seroma formation and promote early recovery, characterized by reduced postoperative edema, improved patient comfort, and an uncomplicated short-term postoperative course. Further controlled studies are needed to validate these findings and establish standardized drainage protocols in lipedema surgery.

Background:  Lipedema is a progressive subcutaneous adipose tissue disorder predominantly affecting women. Characterized by painful nodules and inflammation, it impairs mobility and quality of life. Traditional nonsurgical treatments currently offer limited relief and necessitate additional interventions. This study aimed to evaluate the efficacy of SMiLE (Softening, Mobilization, Liposuction, Extraction), a lipedema reduction surgery (LRS) technique. This technique combines lymphatic-sparing liposuction with manual lipedema extraction to comprehensively remove lipedema nodules. Methods:  Sixty-two women who underwent LRS with the SMiLE technique by the primary author participated in the study and completed an online survey. Data were collected on prior medical history related to lipedema development and comorbidities and outcome measures such as pain, activities of daily living, and quality of life before and after surgery. Results:  The findings demonstrate significant improvements in patients’ daily lives following surgery. Pain levels decreased by an average of 73.9%, with the most notable reduction in the buttock shelf (81.3%). Mobility improved for 93% of participants who had faced challenges before LRS, and quality-of-life assessments indicated a 47.5% reduction in the negative impact of lipedema postsurgery. Conclusions:  The SMiLE technique offers an advancement in the surgical management of lipedema by enabling the effective removal of lipedema tissue. Alongside a reduction in pain and improvement in mobility, this method addresses physical and psychological burdens. This study suggested that the SMiLE technique could be considered an option as part of a comprehensive approach to treating patients with lipedema.

Background: Emerging evidence suggests that lipedema may share hormonal, inflammatory, and genetic mechanisms with gynecologic diseases, particularly endometriosis. However, the extent and nature of these interrelationships remain poorly characterized, supporting the need for this scoping review. Objectives: To map and synthesize the available evidence on the clinical, pathophysiological, and epidemiological interrelationships between lipedema in women, endometriosis, and other gynecologic diseases. Methods: Searches were conducted in international and regional health databases, including MEDLINE (PubMed), CINAHL, Scopus, Embase, Web of Science, the Cochrane Library, LILACS/VHL, APA PsycInfo, SciELO, Epistemonikos, and La Referencia, as well as grey literature sources and relevant institutional websites. There were no language restrictions. The search period began in 1940, the year in which lipedema was first described by Allen and Hines. Study selection followed a two-stage process conducted independently by two reviewers, consisting of title and abstract screening followed by full-text review. Data extraction was performed using a pre-developed and peer-reviewed instrument covering participants, concept, context, study methods, and main findings. The review protocol was registered in the Open Science Framework. Results: Twenty-five studies from ten countries were included. Synthesized evidence supports the characterization of lipedema as a systemic condition with metabolic and hormonal dimensions. Key findings include symptom onset linked to reproductive milestones, a high frequency of gynecologic and endocrine comorbidities, and molecular features overlapping with steroid-dependent pathologies. These patterns reflect a recent shift from a predominantly lymphovascular paradigm toward a more integrated endocrinometabolic framework. Conclusions: The findings indicate that lipedema clusters with hormone-sensitive gynecologic and endocrine features across reproductive life stages.

Objective: The aim of this study was to identify the demographic and clinical characteristics of patients with lipedema who presented to our outpatient clinic in Çorum, thereby contributing to defining the lipedema case profile in our country. Material and Methods: We included 80 female patients diagnosed with lipedema at the physical medicine and rehabilitation outpatient clinic of our hospital between January 2020-July 2023. Data on age, body mass index (BMI), lipedema type-stage, and symptoms were collected from medical records. Laboratory evaluations, including hemogram, 25-OH vitamin D, vitamin B12, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and lower limb venous doppler ultrasound results were also obtained from medical records. Results: The mean age was 46.46±9.72 years and BMI was 32.12±4.84. Type 2 lipedema was the most common, followed by Type 1 and Type 3. Stage 2 lipedema was seen in 63.8% of the patients, stage 1 in 21.2%, and stage 3 in 15%. Common symptoms included pain, swelling, fatigue, and leg heaviness. The mean CRP was 4.88±2.89 mg/L, ESR was 18.58±10.06 mm/h, 25-OH vitamin D was 18.73±12.95 ng/dl, and vitamin B12 was 359.74±155.12 pg/ml. Venous insufficiency was present in 50% of the patients. Lipedema stage showed significant positive correlations with age (r: 0.284, p: 0.011), BMI (r: 0.307, p: 0.006), and ESR (r: 0.271, p: 0.015).Conclusion: Patients presenting with swelling and pain in the lower limbs should always be assessed for lipedema, and it should also be considered that venous insufficiency and vitamin deficiencies may coexist in these patients.

Lipoedema is a chronic, progressive condition characterised by disproportionate fat accumulation in the lower extremities, often misdiagnosed due to symptom overlap with obesity. Weight management is a key component of lipoedema treatment, yet the role of bariatric surgery remains unclear. This systematic review evaluates the impact of bariatric and metabolic surgery (BMS) on lipoedema symptoms, weight loss outcomes, and the need for further interventions.A systematic search of PubMed, Scopus, and the Cochrane Library was conducted up to January 2025 following PRISMA guidelines. Studies reporting on patients with lipoedema (or equivalent diagnoses) who underwent BMS were included. Quality was assessed using the Joanna Briggs Institute (JBI) checklist for case reports and the National Heart, Lung, and Blood Institute (NHLBI) tool for case series.Seven studies met the inclusion criteria (five case reports, two cohort studies), comprising 51 patients. All underwent BMS, primarily sleeve gastrectomy or Roux-en-Y gastric bypass. One study (n=31) reported a significant reduction in thigh volume and weight loss comparable to controls. The remaining studies found persistent or worsened lower body disproportionality and no improvement in pain. Postoperative lipoedema diagnoses were common, raising concerns over diagnostic accuracy. Overall weight loss averaged 33.9% total weight loss.Bariatric and metabolic surgery achieves meaningful weight reduction in lipoedema patients with obesity but does not consistently improve core lipoedema symptoms. Its role remains adjunctive rather than primary. Larger prospective studies using standardised definitions and outcome measures are needed to clarify its therapeutic value in this population.

ObjectivesLipedema is a chronic condition that predominantly affects women, leading to painful, disproportionate fat distribution in the limbs. This systematic review and meta-analysis aimed to characterize health-related quality of life (HRQoL) across multiple domains in individuals with lipedema.MethodsWe systematically reviewed studies from inception to 3 July 2025 in MEDLINE (via PubMed) and Cochrane Controlled Register of Trials (CENTRAL) that primarily assessed HRQoL in individuals with lipedema. Data were extracted from studies using HRQoL assessment scales. The methodological quality of included studies was assessed using an adapted version of the Newcastle-Ottawa Scale for cross-sectional studies. The review protocol was pre-registered with PROSPERO (CRD42024590792). A random-effects meta-analysis was conducted to compute pooled mean HRQoL scores across various domains.ResultsFourteen cross-sectional studies involving nine countries and 3851 participants were included. The meta-analysis found significant impairments in multiple HRQoL domains: physical functioning (61.19, 95% CI: 56.77-65.60), pain (51.77, 95% CI: 45.01-58.53), social functioning (63.24, 95% CI: 58.44-68.04), emotional well-being (64.19, 95% CI: 59.86-68.52), and energy/fatigue (43.50, 95% CI: 39.32-47.68).ConclusionLipedema significantly affects HRQoL, with major deficits in physical, emotional, and social functioning. These findings highlight the need for greater clinical awareness and comprehensive management strategies, including both physical and psychological interventions, to improve the quality of life for individuals with lipedema. Further research is needed to explore long-term effects and optimize treatment approaches.

Background: Emerging evidence suggests that lipedema may share hormonal, inflammatory, and genetic mechanisms with gynecologic diseases, particularly endometriosis. However, the extent and nature of these interrelationships remain poorly characterized, supporting the need for this scoping review. Objectives: To map and synthesize the available evidence on the clinical, pathophysiological, and epidemiological interrelationships between lipedema in women, endometriosis, and other gynecologic diseases. Methods: Searches were conducted in international and regional health databases, including MEDLINE (PubMed), CINAHL, Scopus, Embase, Web of Science, the Cochrane Library, LILACS/VHL, APA PsycInfo, SciELO, Epistemonikos, and La Referencia, as well as grey literature sources and relevant institutional websites. There were no language restrictions. The search period began in 1940, the year in which lipedema was first described by Allen and Hines. Study selection followed a two‐stage process conducted independently by two reviewers, consisting of title and abstract screening followed by full‐text review. Data extraction was performed using a predeveloped and peer‐reviewed instrument covering participants, concept, context, study methods, and main findings. The review protocol was registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/D65GS). Results: Twenty‐five studies from ten countries were included. Synthesis of the available evidence indicates that lipedema is consistent with a systemic condition involving metabolic and hormonal dimensions, characterized by onset related to reproductive milestones, a high frequency of gynecologic and endocrine comorbidities, and molecular features overlapping with steroid‐dependent pathologies. These findings reflect a recent shift from a predominantly lymphovascular paradigm toward a more integrated endocrinometabolic framework. Conclusions: The findings indicate that lipedema clusters with hormone‐sensitive gynecologic and endocrine features across reproductive life stages.

Background/Objectives: Lipedema is a chronic, progressive adipo-fascial disorder characterized by connective tissue dysfunction, fibrosis, microangiopathy, and adipose tissue proliferation. Although lipedema has traditionally been described as a regionally confined disorder, emerging evidence suggests that it may reflect a broader stromal and connective tissue dysfunction. It is therefore plausible that anatomical regions not historically associated with lipedema may also exhibit alterations consistent with this dysfunctional stromal pattern. From this perspective, breast tissue-rich in fibro-glandular and stromal components-represents a compelling model in which to investigate whether such features are present. The breast, with its complex fibro-glandular and stromal architecture, represents a physiologically plausible site of involvement; however, its structural features in lipedema have never been systematically examined. The primary aim of this study was therefore to determine whether breast tissue-rich in fibro-glandular and stromal components-shows recurrent imaging or histopathological features suggestive of lipedema-related involvement. A secondary aim was to compare the frequency of these findings with patterns typically reported in healthy screening populations. Methods: This retrospective cross-sectional study analyzed 62 women (mean age: 44 ± 8 years), obtained between September and November 2025, with a clinical diagnosis of lipedema who voluntarily provided breast imaging reports (ultrasound, mammography, or magnetic resonance imaging, MRI). Results: The findings revealed a remarkably high prevalence of fibro-glandular parenchyma (45%), multiple diffuse cysts (42%), microcalcifications (21%), and fibroadenomas (43.5%), with frequencies substantially exceeding those documented in healthy screening populations. Additional features included significant breast asymmetry or tuberous morphology (6%), reactive or sclero-lipomatous lymph nodes (19%), and recurrent stromal hyperplasia on biopsy. Histological evaluations (n = 9) consistently showed fibroproliferative alterations, including stromal hypercellularity, adenosis, fibroepithelial lesions, apocrine metaplasia, and pseudoangiomatous stromal hyperplasia, suggesting a shared extracellular matrix-related dysplastic phenotype between lipedema-affected breast tissue and peripheral adipose tissue. Conclusions: These findings support the hypothesis that lipedema may express a characteristic breast phenotype driven by stromal and extracellular matrix dysregulation. If confirmed in larger controlled studies, these recurrent alterations could contribute to improved diagnostic frameworks and raise awareness of lipedema as a systemic connective tissue disorder with underrecognized breast manifestations.

INTRODUCTION: Lipedema is a chronic inflammatory disease characterized by symmetrical deposition of adipose tissue in the upper and lower limbs, disproportionate to the trunk. It primarily affects women. The objective of this study was to evaluate the effects of surgical treatment in patients with lipedema who are refractory to conservative management. METHODS: We conducted a systematic review and single-arm meta-analysis in accordance with PRISMA guidelines. Retrospective studies involving patients who underwent surgical treatment after failing clinical management were included. Means and proportions were pooled using the inverse variance method and logit transformations, and heterogeneity was assessed using the I2 statistic. RESULTS: We included 6 studies comprising 429 patients, with follow-up ranging from 6 months to 44 months. In this meta-analysis, surgical treatment with tumescent liposuction resulted in significant clinical improvements for patients with lipedema. The pooled mean preoperative pain score was 5.64 (95% CI: 3.67-8.69), which decreased to 1.19 (95% CI: 0.91-4.22) postoperatively. Sensitivity to touch or pressure was reduced from a preoperative mean of 5.77 (95% CI: 4.10-8.10) to 1.96 (95% CI: 1.17-3.29) after surgery. Swelling scores improved from 5.47 (95% CI: 3.73-8.02) preoperatively to 2.14 (95% CI: 1.31-3.48) postoperatively, while restriction of movement scores decreased from 3.76 (95% CI: 2.48-5.72) to 0.77 (95% CI: 0.36-1.64). CONCLUSION: The results of this single-arm meta-analysis, which included six studies and 429 patients with lipedema refractory to clinical treatment and undergoing surgical intervention, demonstrate that tumescent liposuction is associated with reductions in postoperative pain and edema, as well as improvements in cosmetic outcomes, quality of life, and mobility. The duration of follow-up was adequate to capture relevant clinical outcomes and adverse events. However, lipedema remains a condition that requires further high-quality studies to define the optimal therapeutic approach. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 ."

Background: Lipedema is a progressive disorder of subcutaneous connective tissue, predominantly affecting women, and characterized by an increase in subcutaneous adipose tissue, particularly in the lower body. This study aims to explore the gut microbiota (GM) profile in lipedema patients to characterize the associated GM and compare it with the control group. Methods: A prospective randomized case-control pilot study was conducted from September 2023 to May 2024, involving 55 Caucasian women, aged 20-60. The participants were divided into two groups: 35 with lipedema (LIPPY) and 20 controls (CTRL). Body composition was assessed using Dual X-ray Absorbimetry (DXA), and GM analysis was performed through 16S rRNA gene sequencing. Results: LIPPY subjects showed increased Intramuscular Adipose Tissue (IMAT) and reduced Lean Mass (LM)/Fat Mass (FM) ratios. While alpha and beta diversity metrics did not differ significantly between groups, differential abundance analysis identified a significant reduction in Eggerthellaceae (Log Fold Change (LFC) = -0.19, p = 0.04) and enrichment of Propionibacteriaceae (LFC = +0.18, p = 0.009) and Acidaminococcaceae (LFC = +0.32, p = 0.013) in the LIPPY group. Genus-level analysis showed a significant reduction in Blautia and Ruminiclostridium (LFC = -0.32 and -0.02; p = 0.02 and 0.04) and enrichment of Anaerostipes, Propionibacterium, and Phascolarctobacterium (LFC = +0.07, +0.17, and +0.34; p = 0.02, 0.005, 0.005, respectively). In correlation analyses, within LIPPY, Eggerthellaceae correlated negatively with Body Mass Index (BMI) (ρ = -0.61, p < 0.05) and positively with Appenicular (Appen) LM/Weight and AppenLM/BMI (ρ = +0.43 and +0.41, p < 0.05), while Anaerostipes correlated positively with these lean mass indices (ρ = +0.40, p < 0.05). In CTRL, only Anaerostipes showed a significant negative correlation with BMI (ρ = -0.64, p < 0.05). Conclusions: This study provides the first evidence of a distinct GM profile in LIPPY, with notable links to adverse body composition markers such as IMAT. Trial Registration: Trial registered on 24 June 2013 with ClinicalTrial.gov (NCT01890070).

Background/Objectives: Lipedema is a chronic disorder that affects almost exclusively women and is characterized by bilateral, symmetrical accumulation of subcutaneous fat, typically in the buttocks, hips, and lower limbs, and in some cases the arms. The primary objective of this study was to describe the clinical and anatomical manifestations of lipedema, together with the associated physical and psychological comorbidities, in a large Spanish cohort. Methods: Descriptive study of 1803 patients aged ≥ 17 years who attended two clinics in Spain between January 2022 and November 2024. Results: The mean age was 42.9 years (SD: 11.3), and 60.6% of patients were diagnosed during their reproductive years. The mean body mass index was 28.6 (SD: 6.2), and 87.6% presented a gynoid fat distribution. A total of 46.6% were classified as Schingale stage IV or V. The most frequent comorbidities were chronic low-grade inflammatory alterations and connective tissue damage. Particularly suspected high intestinal permeability (99%), bilateral trochanteric pain region (97.4%), iliotibial band involvement, and ligamentous hyperlaxity (95.8%). Thyroid disorders, inflammatory ovarian dysfunction, and psychological impairment were also common. Conclusions: Lipedema is a complex condition that extends beyond lower-limb adipose tissue and is associated with multiple comorbidities. This study also presents a novel approach to clinical assessment that may help physicians gain a deeper understanding of this pathology and formulate etiological hypotheses that will need to be tested.