Received Jun 17, 2026
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| UNK | VACCINE NOT SPECIFIED (NO BRAND NAME) | UNKNOWN MANUFACTURER | UNK | No batch number | — |
Rhabdomyolysis; 3+ hematuria; 3+ Proteinuria; Acute tubular injury; Generalized myalgia; Weakness; Foamy urine; Beer coloured urine; Mucosal palor; This literature report (initial receipt 22-May-2026) concerns an elderly female patient who developed rhabdomyolysis post Flucelvax vaccination. The patient with a past medical history of morbid obesity, type 2 diabetes mellitus, hypertension, and microcytic anemia with a baseline creatinine of 0.67mg/dl. One month prior, she had a routine visit to her Primary Care Physician (PCP), and received Seqirus Influenza Flucelvax 0.5ml (Lot no. to be requested upon follow-up) after which she developed generalized myalgia for two weeks. Her myalgia improved but she then experienced weakness, described beer' coloured, foamy urine and endorsed decreased output for the following two weeks. When she presented to the Emergency Department, she had normal vital signs and physical examination except for mucosal palor. Imaging was negative for obstruction, and investigations showed an admission creatinine of 9.1mg/dl, negative Anti-GBM antibody, anti-nuclear antibody, double-stranded deoxyribonucleic acid (DNA) antibody, p and c- antineutrophil cytoplasmic antibodies (ANCA), normal creatinine phosphokinase (CPK) and urine myoglobin. Routine urinalysis revealed 3+ hematuria, 3+ proteinuria and her urine protein:creatinine ratio was 7g/g. A renal biopsy was performed which showed acute tubular injury with positive staining myoglobin casts. She required three sessions of hemodialysis after which she begins to recover renal function, and her creatinine had stabilized at 6.3mg/dl. Three weeks after hospital discharge, she was able to remain off dialysis and her creatinine improved to 1.66mg/dl. Author's comment Rhabdomyolysis can have a delayed presentation and can present as an acute kidney injury (AKI) of unknown etiology. Myoglobin is well known for its cytotoxic effects but as shown in this case, can persist in the renal tubules in the setting of normal CPK and urine myoglobin. We should always consider rhabdomyolysis in the differential and diagnostic workup of AKI with appropriate staining of renal biopsy samples.; Reporter's Comments: Causality: Due to the spontaneous nature of the case, all events are considered related for reporting purposes. There is a plausible temporal association (approximately two weeks) between Flucelvax administration and the onset of myalgia, which subsequently progressed to rhabdomyolysis, with released myoglobin leading to acute kidney injury. The events of asthenia, chromaturia, urine abnormality, haematuria, and proteinuria are considered consistent with the clinical manifestations of rhabdomyolysis and its associated renal involvement. Of note, the patient's elderly age and underlying comorbidities, including morbid obesity and type 2 diabetes mellitus, may have contributed as confounding factors.
Hypertension; Morbid obesity; Type 2 diabetes mellitus
Medical History/Concurrent Conditions: Microcytic anemia; Renal biopsy
Test Name: Urine protein:creatinine ratio; Test Result: 7 {DF}; Test Name: Creatinine; Test Result: 1.66 {DF}; Test Name: Creatinine; Test Result: 6.3 {DF}; Test Name: Creatinine; Test Result: 9.1 {DF}