Polymyalgia rheumatica

An Unusual Side Effect of the COVID-19 Vaccine: A Possible Trigger of Polymyalgia Rheumatica

Polymyalgia rheumatica (PMR) is characterized by myalgia and severe stiffness with decreased range of motion in the shoulder and pelvic girdles. The efficacy of the BNT 162b2 Pfizer vaccine has been proven and has been well-tolerated by patients; however, some instances of PMR have been reported after the COVID-19 vaccine. We are writing a case of a new-onset PMR in a 72-year-old woman with typical findings after receiving a booster dose of the BNT 162b2 Pfizer vaccine. This case report highlights that PMR should be in the differential diagnosis of myalgias caused by the vaccine. 

Erythrocyte sedimentation rate and C-reactive protein in the evaluation of disease activity and severity in polymyalgia rheumatica: a prospective follow-up study

OBJECTIVE

To determine the frequency and clinical features of patients with polymyalgia rheumatica (PMR) and normal erythrocyte sedimentation rate (ESR) at diagnosis or during relapse/recurrence. To evaluate the usefulness of C-reactive protein (CRP) and ESR in the assessment of PMR activity.

METHODS

A prospective follow-up study on 177 consecutive patients meeting the criteria for PMR diagnosed over a 5-year period was conducted in two Italian secondary referral centers of rheumatology. At diagnosis and during follow-up, ESR (Westergren method) and CRP (nephelometry) were measured in all patients. Phenotypic analysis of lymphocyte subpopulations was performed on 78 PMR patients at diagnosis. A two-color technique using the association of specific monoclonal antibodies was applied. A control group consisting of 18 healthy adults older than 60 years was matched for age and sex with the PMR patients.

RESULTS

Ten of 177 (6%) patients had normal ESR values at diagnosis (< or = 30 mm/h). Patients with normal ESR were predominantly men and had lower CRP levels; systemic signs and symptoms were more frequent in patients with higher ESR. The percentages of circulating CD8+ cells were similar in the two groups. CRP values at diagnosis were normal in only 2 of 177 (1%) patients. CRP values were elevated in 9 of 10 patients with normal ESR at diagnosis. Twenty-five episodes of relapse/recurrence with normal ESR occurred in 17 patients. CRP was high in 62% of these episodes. Results of univariate analysis indicated that the 10th percentile for ESR (40 mm/h) and the 70th percentile for CRP (7.8 mg/dL) values at diagnosis were the best cutoff points that discriminate between patients with and without relapse/recurrence. Cox proportional hazards modeling showed that ESR greater than 40 mm/h and CRP greater than 7.8 mg/dL at diagnosis were the two variables that independently increased the risk of relapse/recurrence. However, the relative risk related to ESR was twice than that related to CRP (4.9 vs 2.1).

CONCLUSION

PMR with a normal ESR at diagnosis was infrequent in our study compared with previous studies. ESR was a superior predictor of relapse than CRP. However, CRP was a more sensitive indicator of current disease activity.