Collagen cross-links in fibromyalgia syndrome

Psoriasis and Fibromyalgia: A Systematic Review

Psoriasis is a chronic inflammatory cutaneous condition characterized by several comorbidities, including musculoskeletal disorders. While the association with psoriatic arthritis has been widely addressed in literature, the aim of the present systematic review was to identify all available evidence on the relationship between psoriasis and fibromyalgia, a musculoskeletal syndrome primarily characterized by chronic widespread pain. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and MedLine and Web of Science (WOS) databases were searched for literature up to March 2023. After the removal of duplicate records, a total of 11 articles were deemed eligible for inclusion in a qualitative synthesis. Our results suggested that psoriatic patients had a higher prevalence of fibromyalgia (8-30%), with a very high impact on symptoms of psoriasis. Moreover, fibromyalgic patients had a slightly increased prevalence of psoriasis (2.2-6.7%) compared to the control groups. Finally, several studies demonstrated the substantial impact of fibromyalgia on psoriatic outcome measures in patients with concomitant psoriatic arthritis. In conclusion, available data support a potential interplay between psoriasis and fibromyalgia, but further research is encouraged in this area.

Dermatologic manifestations of fibromyalgia

The aim of this study was to determine the common dermatologic diagnoses and skin-related symptoms in a cohort of patients with fibromyalgia seen in a tertiary referral center. A retrospective chart review was performed of all patients with a fibromyalgia diagnosis from January 1 to December 31, 2008, whose diagnosis was confirmed in the Fibromyalgia and Chronic Fatigue Clinic at Mayo Clinic in Rochester, Minnesota. Charts were reviewed for dermatologic conditions and cutaneous symptoms. Demographic and clinical data were collected to assess the frequency of skin-related issues in patients with fibromyalgia. Of 2,233 patients screened, 845 patients met the inclusion criteria of having a confirmed diagnosis of fibromyalgia. Among these fibromyalgia patients, various dermatologic conditions and cutaneous problems were identified, including hyperhidrosis in 270 (32.0 %), burning sensation of the skin or mucous membranes in 29 (3.4 %), and various unusual cutaneous sensations in 14 (1.7 %). Pruritus without identified cause was noted by 28 patients (3.3 %), with another 16 patients (1.9 %) reporting neurotic excoriations, prurigo nodules, or lichen simplex chronicus. Some form of dermatitis other than neurodermatitis was found in 77 patients (9.1 %). Patients with fibromyalgia may have skin-related symptoms associated with their fibromyalgia. No single dermatologic diagnosis appears to be overrepresented in this population, with the exception of a subjective increase in sweating.

Mechanisms underlying development of spatially distributed chronic pain (fibromyalgia)

Chronic fibromyalgia (FM) pain is prevalent (estimated as high as 13%), predominantly affects women, and is associated with a variety of focal pain conditions. Ongoing FM pain is referred to deep tissues and is described as widespread but usually is maximally located within a restricted region such as the shoulders. Palpation of deep tissues reveals an enhanced nociceptive sensitivity that is not restricted to regions of clinical pain. Similarly, psychophysical testing reveals allodynia and hyperalgesia for cutaneous stimulation at locations beyond regions of clinical pain referral. The combination of widely distributed clinical pain and generalized hypersensitivity is highly disabling, but no satisfactory treatment is regularly prescribed. A thorough understanding of mechanisms will likely be required to develop and document adequate therapies. The generalized hypersensitivity associated with FM has focused considerable interest on central (CNS) mechanisms for the disorder. These include central sensitization, central disinhibition and a dysfunctional hypothalamic-pituitary-adrenal (HPA) axis. However, the central effects associated with FM can be produced by a peripheral source of pain. Chronic nociceptive input induces central sensitization, magnifying pain, and it activates the HPA and the sympathetic nervous system. Chronic sympathetic activation indirectly sensitizes peripheral nociceptors and sets up a vicious cycle. Thus, it appears that central mechanisms of FM pain are dependent on abnormal peripheral input(s) for development and maintenance of this condition. A substantial literature defines peripheral-CNS-peripheral interactions that are integral to FM pain. These reciprocal actions and related phenomena of relevance to FM pain are reviewed here, leading to suggestions for testing of therapeutic approaches.

Simultaneous recording of late and ultra-late pain evoked potentials in fibromyalgia

OBJECTIVE

To characterize laser evoked potentials (LEP), pain psychophysics and local tissue response in fibromyalgia patients.

METHODS

LEP were recorded in 14 women with fibromyalgia in response to bilateral stimulation of tender and control points in upper limbs by 4 blocks of 20 stimuli at each point. Subsequently, heat pain thresholds were measured and supra-threshold magnitude estimations of heat pain stimuli were obtained on a visual analogue scale. Finally, the extent of the local tissue response induced by the previous stimuli was evaluated.

RESULTS

Laser stimuli elicited two long latency waves: A late wave (mean latency 368.9+/-66.9 ms) in most patients (13/14) from stimuli at all points, and an ultra-late wave (mean latency 917.3+/-91.8 ms) in 78.5% of the patients at the control points and in 71.4% at the tender points. Amplitude of ultra-late waves was higher at the tender points (20.67+/-11.1 microV) than at the control points (10.47+/-4.1 microV) (P=0.016). Pain thresholds were lower in the tender (41.2+/-2.7 degrees C) than the control points (43.9+/-3.2 degrees C) (P=0.008). Local tissue response was significantly more intense at tender than control points (P=0.004).

CONCLUSIONS

Ultra-late laser evoked potentials can be recorded simultaneously with late potentials. Our findings are compatible with presence of peripheral C-fiber sensitization, mostly at tender points, probably combined with generalized central sensitization of pain pathways in fibromyalgia.