Sex: M
Vaccine: RSV
Symptoms: Polymyalgia rheumatica, Rheumatoid factor negative, Tension headache, White blood cell count increased
Clinical narrative: Polymyalgia rheumatica; infrequent chronic headaches described as a band; This is a literature report.  A 72-year-old male patient visited the internal medicine clinic, complaining of muscle and joint pain that had been persisting for two months. The patient mentioned receiving the Abrysvo RSV vaccine three days before the sudden onset of his symptoms. He reported significant bilateral hip pain that was associated with stiffness. A few days later, he had similar symptoms in both shoulders. The patient experienced significant morning stiffness lasting more than an hour, until around noon; his symptoms improved later in the day. The stiffness greatly limited his ability to move during activities such as rising from a seated position and reaching overhead. The patient denied similar symptoms previously and actively in other joints, such as the hands and feet. The patient reported infrequent chronic headaches described as a band that improves with paracetamol. The character and frequency of headaches had not changed recently. He reported no jaw claudication, tongue pain with mastication or temporal throbbing pain, and denied any visual changes such as blurry vision, floaters, scotomas or transient vision loss. A review of systems was negative for constitutional symptoms (fever, weight loss, night sweats), rash, joint swelling and erythema. The past medical history was significant for obstructive sleep apnoea, atrial fibrillation, coronary artery disease, benign prostate hyperplasia and dyslipidaemia. The patient had been taking atorvastatin for many years without any side effects or myalgia. The family history was significant for rheumatoid arthritis. The initial workup results were a C-reactive protein (CRP) of 50 mg/l (normal range <5 mg/l), neutrophilic leukocytosis (leukocytes 13.5 * 109/l, neutrophils 75%), rheumatoid factor <10 IU/ml (normal range <15 IU/ml), cyclic citrullinated peptide antibody <15.6 U (negative <20 U), creatine kinase 97 U/l (normal range 39-308 U/l) and a complete metabolic panel within the normal range. A computed tomography (CT) angiogram of the chest and abdomen did not show any radiological evidence of large vessel vasculitis. The patient was started on a prednisone taper (40 mg daily for seven days, 30 mg daily for seven days, followed by 15 mg daily for 14 days). Prior to the CT scan, the patient was started on a higher dose for concerns of giant cell arteritis. The patient had a dramatic improvement in his symptoms after starting the prednisone. A CRP within the normal range (<3 mg/l) was noted two weeks after starting treatment. The patient had a follow-up after completing the prednisone taper. He reported that the stiffness initially resolved on the higher prednisone dose; however, the 15 mg dose was associated with increased morning stiffness in bilateral shoulders and hips. On a repeat CRP test, it was elevated to 13.7 mg/l. The patient was evaluated by the rheumatology service, which confirmed the diagnosis of PMR. They recommended a slow taper of prednisone or a trial of tocilizumab, an interleukin-6 inhibitor, to reduce the total steroid requirement. The patient chose to undergo a slow steroid taper and to consider tocilizumab if symptoms were refractory.; Sender's Comments: Based on the temporal relationship, the association between the event polymyalgia rheumatica with ABRYSVO can not be fully excluded.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.