Allergy/hypersensitivity reactions as a predisposing factor to complex regional pain syndrome I in orthopedic patients

Skin biomarkers associated with complex regional pain syndrome (CRPS) Type I: a systematic review

Despite increasing research, the pathophysiology of Complex Regional Pain Syndrome (CRPS) remains poorly understood. Due to its easy accessibility, the skin represents an ideal approach to gain a better understanding of the underlying processes. We conducted a systematic review of original studies investigating potential biomarkers cutaneous biomarkers in CRPS. Original articles with a minimum level IV of evidence were screened using the following databases: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and Web of Science Core Collection. Quality assessment was performed using the Methodological Index for Non-Randomized Studies criteria. A total of 11 studies exploring cutaneous biomarkers in 299 CRPS Type I patients were included. The biomarkers identified revealed implications of the following pathophysiological processes: inflammation via interleukins and TNF-a, vascular dysregulation (ET-1/NOx disturbances and hypoxia-high lactate), small fiber neuropathy and hypersensitivity. In terms of skin morphology, evidence suggests: neurite loss, increased expression and disturbed migration of mast cells, as well as an increased expression of α1-adrenoceptors on keratinocytes. The data supporting hypersensitivity had a high risk of bias on quality assessment. The current review has emphasized the current state of knowledge regarding the cutaneous biomarkers in patients suffering from CRPS Type I. Our results serve as a basis for future developments of techniques that would either facilitate diagnosis or may represent therapeutic targets. Trial registration PROSPERO: CRD42020203405. Level of evidence: IV (Systematic Review).

Metal Hypersensitivity and Complex Regional Pain Syndrome After Bilateral Total Knee Arthroplasty: A Case Report

CASE

A 38-year-old man underwent bilateral total knee arthroplasty (TKA) and subsequently developed diffuse pain, swelling, and an eczematous rash that spread throughout his body. Despite various pharmacological regimens, sympathetic blocks, aggressive physical therapy, and further knee revisions, the patient's symptoms progressed over a period of 2 years. An in vitro memory lymphocyte immuno-stimulation assay test demonstrated reactivity to nickel after which bilateral revision TKAs with oxidized zirconium alloys resulted in symptomatic improvement.

CONCLUSION

Metal hypersensitivity should be considered after the exclusion of infection; however, the concurrent development of complex regional pain syndrome may mask the clinical presentation.

Pediatric complex regional pain syndrome: a review

Complex regional pain syndrome (CRPS) is a chronic, intensified localized pain condition that can affect children and adolescents as well as adults, but is more common among adolescent girls. Symptoms include limb pain; allodynia; hyperalgesia; swelling and/or changes in skin color of the affected limb; dry, mottled skin; hyperhidrosis and trophic changes of the nails and hair. The exact mechanism of CRPS is unknown, although several different mechanisms have been suggested. The diagnosis is clinical, with the aid of the adult criteria for CRPS. Standard care consists of a multidisciplinary approach with the implementation of intensive physical therapy in conjunction with psychological counseling. Pharmacological treatments may aid in reducing pain in order to allow the patient to participate fully in intensive physiotherapy. The prognosis in pediatric CRPS is favorable.

Complex regional pain syndrome type I in children. Clinical description and quality of life

INTRODUCTION

Complex regional pain syndrome type 1 (CRPS I) in children differs from its adult counterpart and relevant literature is scarce. Our aim was to investigate potential risk factors and to assess midterm outcome and quality of life.

MATERIAL AND METHODS

Medical records of patients diagnosed with CRPS I between 2004 and 2012 were analyzed. Patients and parents were called for a phone interview including the PEDS Quality of Life 4-0 questionnaire. Results were compared to a control group matched for age, gender and socio-economic status.

RESULTS

Seventy-three patients were included (64 girls, 9 boys). Mean age at diagnosis was 11.5 years and mean time to diagnosis was 14.2 months. The lower limb was affected in 89% of cases. Allodynia, coldness and cyanosis were noted in 95%, 81% and of 74% of cases, respectively. Forty-nine percent of patients reported a physical injury. Multivariate analysis showed a strong association with being anxious (OR = 44.9, 95% CI [7.4-273]), presence of an atopic background (OR = 25.0, 95% CI: [4.6-135]), being good to excellent school performers (OR = 8.4 95% CI [1.3-52.1]), and having trouble falling asleep (OR = 5.3, 95% CI [1.6-17.0]). At a mean 37 months' follow-up (12-102), PEDS QL 4-0 score was significantly lower in CRPS patients compared to controls. Fifty-seven percent of patients acknowledged healing and 55% had presented a relapse.

CONCLUSION

Childhood onset CRPS I affects predominantly preadolescent girls at the ankle. The present study highlights the relatively poor outcome, especially its physical and emotional aspects and the large role of psychology.

LEVEL OF EVIDENCE

IV.