Relationship between the body image and level of pain, functional status, severity of depression, and quality of life in patients with fibromyalgia syndrome

Preserved tactile distance estimation despite body representation distortions in individuals with fibromyalgia

Our mental representation of our body depends on integrating various sensory modalities, such as tactile information. In tactile distance estimation (TDE) tasks, participants must estimate the distance between two tactile tips applied to their skin. This measure of tactile perception has been linked to body representation assessments. Studies in individuals with fibromyalgia (FM), a chronic widespread pain syndrome, suggest the presence of body representation distortions and tactile alterations, but TDE has never been examined in this population. Twenty participants with FM and 24 pain-free controls performed a TDE task on three Body regions (upper limb, trunk, lower limb), in which they manually estimated the interstimuli distance on a tablet. TDE error, the absolute difference between the estimation and the interstimuli distance, was not different between the Groups, on any Body region. Drawings of their body as they felt it revealed clear and frequent distortions of body representation in the group with FM, compared to negligible perturbations in controls. This contrast between distorted body drawings and unaltered TDE suggests a preserved integration of tactile information but an altered integration of this information with other sensory modalities to generate a precise and accurate body representation. Future research should investigate the relative contribution of each sensory information and prior knowledge about the body in body representation in individuals with FM to shed light on the observed distortions.

Psychological Distress in Women with Fibromyalgia: The Roles of Body Appreciation, Self-Compassion, and Self-Criticism

BACKGROUND

While past research detected a direct link between symptoms of fibromyalgia (FM) and psychological distress, body appreciation was suggested as a viable mediator of this link. The aim of the present study was to further develop an explanatory model for the effect of FM on women's psychological distress and identify possible protective and risk factors. Specifically, it was hypothesized that self-compassion would moderate the indirect effect of body appreciation and self-criticism on psychological distress in women with FM.

METHOD

This study comprised a total of 293 women, aged 20-68 (M = 34.8, SD = 12.3), of whom 146 were women with FM and 147 were heathy controls. All the women completed questionnaires regarding demographic characteristics, depression (PHQ-9), anxiety (GAD-7), self-criticism (DEQ-SC), body appreciation (BAS2), and the self-compassion scale (SCS).

RESULTS

A moderated serial mediation model demonstrated lower body appreciation in participants with FM compared to controls. These lower levels of body appreciation, together with lower levels of self-compassion, were associated with greater self-criticism and, consequently, higher levels of psychological distress.

CONCLUSIONS

The results emphasize the role of self-compassion as a protective mechanism against psychological distress among women with FM. Future studies should further investigate the effect of self-compassion-focused interventions on patients with FM.

Hand size estimates of fibromyalgia patients are associated with clinical and experimental pain

Introduction

Simply inspecting one’s own body can reduce clinical pain and magnification of body parts can increase analgesia. Thus, body perceptions seem to play an important role for analgesia. Conversely, pain may also affect bodily perceptions. Therefore, we evaluated the effects of clinical and/or experimental pain on perceived hand size in fibromyalgia patients (FM) and healthy controls (HC).

Methods

To investigate the effects of chronic and/or acute pain on size perception we compared hand size estimates of 35 HC and 32 FM patients at baseline and during tonic mechanical pain stimuli applied to one ear lobe. Mechanical stimuli were adjusted for each individual pain sensitivity to achieve a rating of 4 ± 1 VAS (0–10) units. Photographs of each subject’s hands were digitally manipulated to produce a monotonic series of 5 images larger and 6 smaller than actual size which were then presented to the participants in ascending and descending order (total number of images: 12).

Results

FM and HC participants’ clinical pain ratings at baseline were 3.3 (3.1) and .3 (.8) VAS units, respectively. At baseline, FM participants selected significantly smaller hand images than HC as representative of their actual size (p < .02). During application of tonic experimental pain, the image size chosen to represent their actual hand size decreased significantly in FM participants and HC (p < .001) but this decrease was not different between groups (p > .05). Hand size estimates of FM participants correlated negatively with their clinical pain ratings (p < .04).

Conclusion

The decreased hand size perception of FM patients and HC was associated with their clinical and/or experimental pain, supporting the hypothesis that pain can result in visual body distortions.

Body image dissatisfaction and experimental pressure pain sensitivity in a cohort of 13-year-old adolescents

OBJECTIVE

We aimed to quantify the associations between body image (dis)satisfaction and pressure pain thresholds in adolescents, using data from Generation XXI, a population-based cohort study in Portugal.

METHODS

We assessed 1785 13-year old adolescents cross-sectionally. Body image satisfaction was measured using the Children's Figure Rating Scale. Pain detection and tolerance thresholds were assessed using cuff pressure algometry. We quantified the associations between body image categories (satisfied, prefers slightly thinner, prefers much thinner, and prefers heavier) and pain detection and tolerance thresholds using linear and logistic regression for continuous and binary (odds of achieving the highest distribution quarter) outcomes, respectively. Models were adjusted to pubertal stage and body mass index.

RESULTS

Adolescents who desired a heavier silhouette had lower pressure pain tolerance thresholds when compared to those who were satisfied (linear regression coefficient: -3.95; 95% confidence interval: -6.68, -1.21), which was more precise in boys (-3.51; -7.17, -0.08). Those adolescents also had lower odds of achieving the highest quarter of pressure pain tolerance threshold (odds ratio: 0.66; 0.48, 0.90), especially girls (0.58; 0.35, 0.98). Adolescents who desired much thinner silhouettes had lower odds of achieving the highest quarter of pressure pain tolerance (0.68; 0.46, 1.00), and this was clearer in girls (0.66; 0.48, 0.90). Pain detection thresholds did not show robust associations with body image dissatisfaction.

CONCLUSION

Our study suggests an association between satisfaction with one's silhouette and pain tolerance in adolescents from the general population, arguing for an integrated approach to the assessment of body image and pain sensitivity.

Individuals with fibromyalgia have a different gait pattern and a reduced walk functional capacity: a systematic review with meta-analysis

Background

The aim of the present study was to perform a systematic review and meta-analysis comparing walking test performance and gait pattern between individuals with and without fibromyalgia (FM).

Methodology

This systematic review was registered in PROSPERO with the following reference: CRD42018116200.The search for the scientific articles in this systematic review was carried out using the MEDLINE, SCOPUS, PEDRO, CINHAL and WEB OF SCIENCE databases. A combination of three conceptual groups of terms was used: (1) fibromyalgia; (2) walk (performance) tests; and (3) gait analysis. The included articles were analyzed for both functional and pattern of walking data of patients with FM. In order to provide a better estimate of the difference between individuals with and without FM on gait, a meta-analysis was performed on the 6MWT (6-minute walk test).

Results

Thirty-six studies were analyzed, with a total population of 4.078 participants (3.369 FM and 709 individuals without FM). From a functional point of view, the 6MWT distance covered by the group of individuals without FM was significantly greater than that of the individuals with FM in all the analyzed studies. In addition, when comparing the results obtained in the gait pattern analysis, it was observed that individuals with FM walked slower, with a shorter stride length and lower cadence compare to individuals without FM.

Conclusions

It is possible to affirm that individuals with FM perform walking tests differently than individuals without FM. It was observed that individuals with FM walk performing a cycle of shorter length and lower frequency, producing a slower gait, which results in a shorter distance traveled, in the same period of time, with respect to healthy subjects.

Body Image, Medication Use, and Mental Health among Women with Fibromyalgia in Flanders, Belgium

Fibromyalgia (FM) is a chronic illness that does not have clear physical consequences, yet research shows that FM patients often have a low body image. An online cross-sectional study was conducted in Flanders, Belgium, among FM women who are connected to the Flemish League for fibromyalgia patients. An adjusted Body Image Scale (BIS) was used to assess body image, the General Health Questionnaire-12 (GHQ-12) was used for mental health, and the Visual Analogue Scale Fibromyalgia Impact Questionnaire (VASFIQ) was used for FM symptoms. Medication use was assessed by using a 4-point Likert scale. Time since diagnosis and age was assessed. A total of 103 women with FM responded. Linear regression showed that BIS was best predicted in a model by using VASFIQ, GHQ-12, time since diagnosis, and sleep medication, wherein only the GHQ-12 was significant as a variable (B = 0.292; p = 0.009). This model explained 19.3% of the variance. The role of sleep medication use disappeared when controlling for mental health. Mental health was more clearly associated with body image than medication use, or even fibromyalgia symptoms. Thus, having negative mental health is associated with a negative body image. In order to improve the body image of FM patients, symptom control alone is not enough; improving mental health is equally important.

Tactile Detection in Fibromyalgia: A Systematic Review and a Meta-Analysis

Fibromyalgia is a chronic pain syndrome characterized by sensorimotor deficits and distortions of body representation, that could both be caused by alterations in sensory processing. Several studies suggest a hypersensitivity to various sensory stimulations in fibromyalgia but results on detection of both noxious and non-noxious tactile stimulation, which are particularly relevant for body representation and motor control, remain conflicting. Therefore, the aim of this study is to systematically review and quantify the detection thresholds to noxious and non-noxious tactile stimuli in individuals with fibromyalgia compared to pain-free controls. A systematic review and a meta-analysis were performed in the MEDLINE, EMBASE, CINAHL, Cochrane, PsycInfo and Web of Science databases using keywords related to fibromyalgia, tactile pain detection threshold, tactile detection threshold and quantitative sensory testing. Nineteen studies were included in the review, with 12 in the meta-analysis. Despite the heterogeneity of the results, the data from both the review and from the meta-analysis suggest a trend toward hyperalgesia and no difference of sensitivity to non-noxious tactile stimuli in participants with fibromyalgia compared to healthy controls. This contradicts the hypothesis of a general increase in responsiveness of the central nervous system to noxious and non-noxious stimulations in fibromyalgia. This study shows no alteration of the sensitivity to non-noxious tactile stimulation in fibromyalgia, suggesting that an altered unimodal processing is not sufficient to explain symptoms such as sensorimotor impairments and body representation distortions. Future research should investigate whether alterations in multisensory integration could contribute to these symptoms.

Influence of multidisciplinary therapeutic approach on fibromyalgia patients

There is no specific cure for fibromyalgia (FM), but combined non-pharmacologic and pharmacologic treatments may mitigate symptoms and improve quality of life in patients. The aim of the present study was to monitor patient response to several types of therapy, including cognitive-behavioral and occupational therapy, and kinetic therapy, as compared to a control group that was not subjected to any form of therapy. The study included 98 FM patients, all women, out of which 32 received cognitive-behavioral therapy and occupational therapy (CBT+OT), 34 kinetic therapy (KT) and 32 participated as controls. The evaluation protocol comprised two questionnaires developed in order to assess the patient's condition as fully as possible: Fibromyalgia Impact Questionnaire (FIQ) and Fibro Fatigue (FF) scale. At the pre-evaluation there were no significant inter-group differences. At post-evaluation significant differences were observed between the control sample and the group subjected to kinetic therapy (P<0.05). FIQ scores decreased in the CBT+OT group too, but less than that in the KT group. The FF scale registered notable evolutions in time for the group subjected to kinetic therapy. In order to control and improve most of the FM symptoms, besides proper medication, we suggest an interdisciplinary intervention mainly focusing on long-term individualized kinetic therapy. The simultaneous integration of a cognitive-behavioural and occupational therapy intervention could be the element that completes the complex treatment of FM patients.

Sexual performance and pelvic floor muscle strength in patients with fibromyalgia: a controlled cross-sectional study

BACKGROUND

Fibromyalgia (FM) is characterized by chronic and widespread pain, sleep disturbances, fatigue, psychological distress and morning stiffness. These patients also present symptoms such as depression, sexual dysfunctions and reproductive problems. Sexuality involves several aspects, including pelvic floor functionality, and one question is whether the sexual performance of women with fibromyalgia is associated with pelvic floor function or other characteristics of the disease.

OBJECTIVE

The aim of this study was to gauge the association between perineal function and sexual performance in women with and without fibromyalgia.

METHODS

We performed a cross-sectional study with 109 sexually active women from 19 to 65 years of age, either suffering from fibromyalgia (FM group, n = 51) or free from fibromyalgia (non-FM group, n = 58). Perineal function was measured with the use of perineometry and digital vaginal palpation (PERFECT Scheme), while sexual performance was assessed by the Sexual Quotient Female questionnaire (QS-F).

RESULTS

Patients with fibromyalgia presented poor sexual performance compared to those without fibromyalgia (QS-F score 58 (32-66) vs. 66 (56-70); p = 0.002) as well as lower pelvic floor muscle strength measured by perineometry (32.5 (18.2-40.5) vs. 37.9 (23.4- 57.3); p = 0.03). Patients without fibromyalgia presented a positive correlation between perineometry and QS-F (r = 0.22; p = 0.038), while those with fibromyalgia presented no correlation between those two variables (r = 0.22; p = 0.12). The regression model showed an association between sexual performance and the presence of fibromyalgia, pelvic floor muscle strength (perineometry) and age, according to the following equation: sexual performance = 48.52 + (9.5 * non-FM group) + (0.23 * perineometry)-(0.4 * age), with adjusted R² = 0.19.

CONCLUSION

Women with FM present poor sexual performance and lower pelvic floor muscle strength compared to those without FM. However, the correlation between these variables among women without FM was not observed in women with FM. Sexual performance showed a positive association with absence of fibromyalgia and higher pelvic floor muscle strength, and a negative association with age.

Explicit and Implicit Own's Body and Space Perception in Painful Musculoskeletal Disorders and Rheumatic Diseases: A Systematic Scoping Review

Background: Pain and body perception are essentially two subjective mutually influencing experiences. However, in the field of musculoskeletal disorders and rheumatic diseases we lack of a comprehensive knowledge about the relationship between body perception dysfunctions and pain or disability. We systematically mapped the literature published about the topics of: (a) somatoperception; (b) body ownership; and (c) perception of space, analysing the relationship with pain and disability. The results were organized around the two main topics of the assessment and treatment of perceptual dysfunctions.

Methods: This scoping review followed the six-stage methodology suggested by Arksey and O'Malley. Ten electronic databases and grey literature were systematically searched. The PRISMA Extension for Scoping Reviews was used for reporting results. Two reviewers with different background, independently performed study screening and selection, and one author performed data extraction, that was checked by a second reviewer.

Results: Thirty-seven studies fulfilled the eligibility criteria. The majority of studies (68%) concerned the assessment methodology, and the remaining 32% investigated the effects of therapeutic interventions. Research designs, methodologies adopted, and settings varied considerably across studies. Evidence of distorted body experience were found mainly for explicit somatoperception, especially in studies adopting self-administered questionnaire and subjective measures, highlighting in some cases the presence of sub-groups with different perceptual features. Almost half of the intervention studies (42%) provided therapeutic approaches combining more than one perceptual task, or sensory-motor tasks together with perceptual strategies, thus it was difficult to estimate the relative effectiveness of each single therapeutic component.

Conclusions: To our knowledge, this is the first attempt to systematically map and summarize this research area in the field of musculoskeletal disorders and rheumatic diseases. Although methodological limitations limit the validity of the evidence obtained, some strategies of assessment tested and therapeutic strategies proposed represent useful starting points for future research. This review highlights preliminary evidence, strengths, and limitations of the literature published about the research questions, identifying key points that remain opened to be addressed, and make suggestions for future research studies. Body representation, as well as pain perception and treatment, can be better understood if an enlarged perspective including body and space perception is considered.

Body image, pain and level of resources among arthritis patients: the moderating role of gender

Arthritis is a highly debilitating group of chronic diseases that affects both physical and psychosocial functioning. The aim of this study was to examine the associations between body image, subjective pain intensity and level of resources described by Conservation of Resources (COR) theory among arthritis patients. In particular, the moderating role of the participants' gender was explored via multiple linear regression analysis. 200 arthritis patients were recruited, including 141 females and 59 males. Body image was evaluated using the Multidimensional Body-Self Relations Questionnaire, subjective pain intensity was measured via the Numerical Rating Scale and level of resources was assessed using the COR evaluation questionnaire. A negative relationship was confirmed between the level of satisfaction with body image and pain intensity among participants. A positive relationship was found between body-image subscales and level of COR resources. These relationships were moderated by the participants' gender, i.e. only among males a positive association between body image and pain and, respectively, body image and resources was found. Enhancing body awareness is an essential part of psychological counselling for patients with arthritis and our study added to the literature by showing how body image may be related to pain and resources in this patient group.

Body image is more negative in patients with chronic low back pain than in patients with subacute low back pain and healthy controls

Background and aims Body image as an increasing research field has been integrated into pain research within the last years. However, research on cognitive-affective dimensions of body image dependent on different pain groups like acute/subacute and chronic pain patients, and healthy controls is still lacking. Therefore, this study aims to explore three dimensions of body image, namely self-acceptance, physical efficacy, and health in patients with low back pain and healthy controls. The present study is the first to distinguish between patients with low back pain in different stages of pain with regard to the concept of body image. In a second step we investigated the differences in exercise frequency between the three groups. Methods Seventy seven patients (53.2% female) suffering from low back pain and 57 healthy controls (42.1% female) filled in a battery of questionnaires in terms of body image, pain parameters and exercise frequency. Results Main results indicate first that patients suffering from chronic low back pain revealed a more negative body image in all three body image-dimensions than healthy controls. Second, patients suffering from subacute pain revealed a more negative body image of physical efficacy compared to the healthy controls. Conclusions Our results suggest that body image is relevant for the treatment of low back pain, because patients suffering from low back pain revealed a more negative body image than healthy controls. Implications To investigate the cognitive-affective dimensions of body image in different patient groups suffering from low back pain seems to be an important aspect for future research to improve therapy options and prevention of low back pain. Future research should also focus on improvements or on positive aspects of body image in patients with low back pain.

Embodied pain in fibromyalgia: Disturbed somatorepresentations and increased plasticity of the body schema

Fibromyalgia syndrome (FMS) is a highly prevalent, chronic musculoskeletal condition characterized by widespread pain and evoked pain at tender points. This study evaluated various aspects of body awareness in a sample of 14 women with FMS and 13 healthy controls, such as plasticity of the body schema, body esteem, and interoceptive awareness. To this end, the Rubber Hand Illusion (RHI), the Body Esteem Scale (BES), and the Body Perception Questionnaire (BPQ) were used, respectively. Consistent with increased plasticity of the body schema, FMS patients scored higher, with large or very large effect sizes, across all three domains evaluated in the RHI paradigm, namely proprioceptive drift and perceived ownership and motor control over the rubber hand. Scores on all items addressed by the BES were consistently lower among FMS subjects (2.52, SEM .19 vs 3.89, SEM .16, respectively, p < .01, Cohen’s d = .38-.66). In the FMS sample, BES scores assigned to most painful regions also were lower than those assigned to the remaining body sites (1.58, SEM .19 vs 2.87, SEM .18, respectively, p < .01). Significantly higher scores (p < .01, Cohen’s d = .51-.87) were found in the FMS sample across awareness (3.57 SEM .15 vs 1.87 SEM .11), stress response (3.76 SEM .11 vs 1.78 SEM .11), autonomic nervous system reactivity (2.59 SEM .17 vs 1.35 SEM .07), and stress style 2 (2.73 SEM .27 vs 1.13 SEM .04) subscales of the BPQ. Intensity of ongoing clinical pain was found to be strongly correlated with interoceptive awareness (r = .75, p = .002). The results suggest a disturbed embodiment in FMS, characterized by instability of the body schema, negatively biased cognitions regarding one’s own body, and increased vigilance to internal bodily cues. These manifestations may be interpreted as related with the inability of incoming sensory inputs to adequately update negatively biased off-line somatorepresentations stored as long-term memory.

Controversies and challenges in fibromyalgia: a review and a proposal

Fibromyalgia (FM) is the most commonly encountered chronic widespread pain (CWP) condition in rheumatology. In comparison to inflammatory arthritis (IA), it can seem ill defined with no clear understanding of the pathology and therefore no specific targeted treatment. This inevitably raises controversies and challenges. However, this is an outdated view perpetuated by poor teaching of pain at undergraduate and postgraduate levels, and the perennial problem of advances in relevant cross-speciality knowledge penetrating speciality silos. Research has provided a better understanding of the aetiopathology and FM is now regarded as a centralized pain state. Effective treatment is possible utilizing a multidisciplinary approach combining nonpharmacologic and pharmacologic treatments rooted in a biopsychosocial model. This article will provide a review of the mechanisms, diagnosis and treatment of FM, focus on some ongoing contentious issues and propose a change to the diagnostic terminology.

Exteroceptive and Interoceptive Body-Self Awareness in Fibromyalgia Patients

Fibromyalgia is a widespread chronic pain disease characterized by generalized musculoskeletal pain and fatigue. It substantially affects patients' relationship with their bodies and quality of life, but few studies have investigated the relationship between pain and body awareness in fibromyalgia. We examined exteroceptive and interoceptive aspects of body awareness in 30 women with fibromyalgia and 29 control participants. Exteroceptive body awareness was assessed by a body-scaled action-anticipation task in which participants estimated whether they could pass through apertures of different widths. Interoceptive sensitivity (IS) was assessed by a heartbeat detection task where participants counted their heartbeats during different time intervals. Interoceptive awareness was assessed by the Multidimensional Assessment of Interoceptive Awareness (MAIA). The “passability ratio” (the aperture size for a 50% positive response rate, divided by shoulder width), assessed by the body-scaled action-anticipation task, was higher for fibromyalgia participants, indicating disrupted exteroceptive awareness. Overestimating body size correlated positively with pain and its impact on functionality, but not with pain intensity. There was no difference in IS between groups. Fibromyalgia patients exhibited a higher tendency to note bodily sensations and decreased body confidence. In addition, the passability ratio and IS score correlated negatively across the whole sample, suggesting an inverse relationship between exteroceptive and interoceptive body awareness. There was a lower tendency to actively listen to the body for insight, with higher passability ratios across the whole sample. Based on our results and building on the fear-avoidance model, we outline a proposal that highlights possible interactions between exteroceptive and interoceptive body awareness and pain. Movement based contemplative practices that target sensory-motor integration and foster non-judgmental reconnection with bodily sensations are suggested to improve body confidence, functionality, and quality of life.

Body Image in Adult Women: Moving Beyond the Younger Years

In spite of copious literature investigating body dissatisfaction and its correlates in adolescents and young adult women, exploration of body image disturbances in adult women remains an underrepresented domain in the literature. Yet, there are many reasons to suspect that body image in adult women both may differ from and possibly be more complex than that of younger women. Adult women face myriad factors influencing body image beyond those delineated in the body image literature on adolescents and young adult women. For instance, aging-related physiological changes shift the female body further away from the thin-young-ideal, which is the societal standard of female beauty. Further, life priorities and psychological factors evolve with age as well. As such, adult women encounter changes that may differentially affect body image across the lifespan. This paper aims to provide an up-to-date review of the current literature on the relationship between body image and associated mental and physical health problems and behaviors in adult women. In addition, we explore factors that may influence body image in adult women. Lastly, we use this review to identify significant gaps in the existing literature with the aim of identifying critical targets for future research.

The implications of body-image dissatisfaction among kidney-transplant recipients

The role that body image plays in the psychological adjustment of kidney-transplant recipients is an understudied issue. In the current study, the association between three variables - (a) body-image dissatisfaction, (b) quality of life (QOL), and (c) psychological distress - was investigated. The research participants were 45 kidney-transplant recipients who were under follow-up care at the Transplant Unit of the Tel-Aviv Medical Center (Israel). Body image, psychological distress, and QOL were measured using self-report questionnaires [Body-Image Ideals Questionnaire (BIIQ), Brief Symptoms Inventory (BSI), and SF-12]. Medical and background data were collected from medical and administrative records. The findings indicated an association between higher level of body-image dissatisfaction and a decrease in several quality-of-life dimensions (role emotional, physical pain, general health, and social functioning), and with an increase in psychological distress. These findings highlight the importance of body-image dissatisfaction as a factor that is associated with QOL and psychological distress among kidney-transplant recipients. Body image warrants further attention and should be screened and treated among those who demonstrate high levels of dissatisfaction.

Objective evidence that small-fiber polyneuropathy underlies some illnesses currently labeled as fibromyalgia

Fibromyalgia is a common, disabling syndrome that includes chronic widespread pain plus diverse additional symptoms. No specific objective abnormalities have been identified, which precludes definitive testing, disease-modifying treatments, and identification of causes. In contrast, small-fiber polyneuropathy (SFPN), despite causing similar symptoms, is definitionally a disease caused by the dysfunction and degeneration of peripheral small-fiber neurons. SFPN has established causes, some diagnosable and definitively treatable, eg, diabetes. To evaluate the hypothesis that some patients labeled as having fibromyalgia have unrecognized SFPN that is causing their illness symptoms, we analyzed SFPN-associated symptoms, neurological examinations, and pathological and physiological markers in 27 patients with fibromyalgia and in 30 matched normal controls. Patients with fibromyalgia had to satisfy the 2010 American College of Rheumatology criteria plus present evidence of a physician's actual diagnosis of fibromyalgia. The study's instruments comprised the Michigan Neuropathy Screening Instrument (MNSI), the Utah Early Neuropathy Scale (UENS), distal-leg neurodiagnostic skin biopsies, plus autonomic-function testing (AFT). We found that 41% of skin biopsies from subjects with fibromyalgia vs 3% of biopsies from control subjects were diagnostic for SFPN, and MNSI and UENS scores were higher in patients with fibromyalgia than in control subjects (all P ≤ 0.001). Abnormal AFTs were equally prevalent, suggesting that fibromyalgia-associated SFPN is primarily somatic. Blood tests from subjects with fibromyalgia and SFPN-diagnostic skin biopsies provided insights into causes. All glucose tolerance tests were normal, but 8 subjects had dysimmune markers, 2 had hepatitis C serologies, and 1 family had apparent genetic causality. These findings suggest that some patients with chronic pain labeled as fibromyalgia have unrecognized SFPN, a distinct disease that can be tested for objectively and sometimes treated definitively.