Background Pain is the most common symptom in rheumatic diseases. Its physiopathology generally involves a disturbance in nociceptive perception by tissue damage that often evolves to central pain with features of neuropathic pain (NP). When both components of pain coexist in the same patient, its differentiation is clinically important, since they demand different therapeutical approaches, under the penalty of unsuccessful efforts to relieve pain. NP in spondyloartrhritis remains a scarcely addressed topic.
Objectives To determine the prevalence of NP in a cohort of patients with axial spondyloarthritis (aSpa) and peripheral spondyloarthritis (pSpa) and to assess possible correlations between its presence and disease duration and activity and function indexes.
Methods Cross-sectional study. Analyzed variables: gender, age, disease duration, medication and comorbidities. Pain VAS, DN4 and EQ-5D were assessed in all patients. In patients with aSpa, BASDAI and BASFI were obtained, as well as DAS28 in patients with pSpa. Control group: healthy individuals, adjusted by gender and age to patients. Statistical analysis with SPSS® version 18.0.
Results Ninety four patients were enrolled (46 with aSpa, 48 with pSpa); 54 were males; mean age was 47.87±14.32 years old and mean disease duration was 9.24±10.29 years. Sixteen patients presented DN4≥4 (11 with aSpa and 5 with pSpa); however, only 3 were under medication for that purpose. Mean pain VAS was 4.24±2.5, mean EQ-5D was 7.03±2.09. In aSpa patients, mean BASDAI was 4.34±2.35 and mean BASFI was 3.79±2.64. In pSpa patients, mean DAS28 was 2.59±1.22.
The prevalence of NP was higher in patients comparing to controls (OR=8.62 CI95% (1.1-67.25)). Although NP prevalence increased with disease duration, that difference was only statistically significant in aSpa patients (p=0,034). NP prevalence increases with BASDAI (p=0.0169) in aSpa, the same not being true about BASFI. No relation was found with DAS28 in pSpa. As expected, higher values of pain VAS and EQ-5D were found in patients with DN4≥4 (p<0,02). No statistically significant differences were found in the prevalence of NP in both genders.
Conclusions This study reveals an important neuropathic component in our cohort, superior to control group. NP is present in a significant percentage of patients with aSpa and pSpa, and most of them are not under any medication to target it, hampering an adequate control of symptoms. This work highlights the need of a deeper insight into pain mechanisms and types in Spa patients, since nociceptive pain might be just a part of it.
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Disclosure of Interest None declared