Background Chronic pain syndromes in children lead to significant suffering and functional impairment, with long-term impact on academic performance and quality of life. Chronic regional pain syndromes (CRPS) are rare in childhood. Their impact on quality of life and physical functioning has been described, but not yet compared to generalized chronic pain syndromes.
Objectives The objective of this study was to determine if pediatric patients with CRPS differ from those with generalized muskuloskeletal pain with regard to level of pain and functional impairment.
Methods From December 2007 to November 2010, consecutive patients at the German Center for Pediatric Rheumatology admitted as inpatients for multimodal treatment intervention were prospectively enrolled into a dedicated database. Patients were included in the study if they had a confirmed diagnosis of generalized musculoskeletal pain (GMSP)  or CRPS . The following data was extracted from the database: age, gender, duration of symptoms, pain (numeric rating scale), functional impairment (Functional Disability Index, FDI, and Childhood Health Assessment Questionnaire, C-HAQ) at presentation and 8 weeks after admission. Data were analyzed using descriptive statistics and non-parametric methods (Mann-Whitney-U-Test, Wilcoxon signed rank test), where appropriate.
Results 18 Patients with CRPS and 61 with GMSP were extracted from the database (CRPS: 84% female, GMSP 81%). Median age was 11 years (range 8 – 16) in CRPS and 14 years (9 – 17) in GMSP. Patients with CRPS had a median of 3 months (1 – 90) of symptoms prior to admission, compared to 24 months (1 – 144) in GMSP. Patients with CRPS had comparable levels of pain on admission to GMSP (median (range) 6.5 (3-9)vs. 7 (2-10), p=0.821), but significantly more functional impairment (FDI: 21.5 (6-42) vs. 19 (0-45), p=0.001; C-HAQ: 1.0625 (0-1.75) vs. 0.25 (0-1.75), p<0.001). 8 weeks after treatment, patients with CRPS had similar reductions in levels of pain (2 (0-8) vs. 5 (0-9), p=0.324), but lower functional impairment (FDI: 3 (0-35) vs. 14 (0-45), p=0.003; C-HAQ: 0 (0-1.25) vs. 0.25 (0-2.375), p=0.068). Patients with CRPS and GMSP showed significant improvement in both pain (p=0.004) and functional impairment (FDI p=0.003, C-HAQ p=0.001), while patients with GMSP profited significantly regarding pain (p<0.0001), but not in functional impairment (FDI=0.066, C-HAQ p=0.66).
Conclusions Patients with CRPS show comparable levels of pain, but higher functional impairment. However, multimodal treatment leads to a comparable reduction in pain, but significantly more functional improvement compared to patients with GMSP. This might be related to the more pronounced functional disturbance and the shorter duration of symptoms usually observed in CRPS.
Yunus MB, Masi AT. Juvenile primary fibromyalgia syndrome. A clinical study of thirty-three patients and matched normal controls. Arthritis Rheum 1985;28 2: 138-45.
Harden RN, Bruehl S, Stanton-Hicks M, Wilson PR. Proposed new diagnostic criteria for complex regional pain syndrome. Pain Med 2007;8 4: 326-31.
Acknowledgements This study was supported by the “Stiftung Hilfe für das rheumakranke Kind e.V.”
Disclosure of Interest None declared