Atypical Presentation of Exertional Rhabdomyolysis in Older Adults: Two Case Reports and Literature Review

BACKGROUND Rhabdomyolysis (RM) is caused by drugs, trauma, infection, and high-intensity exercise. As a subtype, exertional rhabdomyolysis (ER) is commonly triggered by high-intensity exercise and clinically manifests as myalgia, dark urine, and other symptoms. Auxiliary tests typically show elevated creatine kinase (CK) and myoglobin (Mb) levels. Aggressive rehydration is the primary treatment for RM. After fluid replacement therapy, serum CK levels usually decline rapidly. CASE REPORT We describe 2 patients with ER who displayed atypical symptoms induced by short-term high-intensity physical labor. Both patients initially presented with limb swelling and asthenia; they showed no myalgia or dark urine. The elevated CK levels in both patients were lower than the levels typically observed in ER cases but remained high for a prolonged period (1-3 months). After aggressive fluid replacement therapy, clinical symptoms gradually improved in both patients, and CK levels slowly decreased. Follow-up evaluations after discharge confirmed full recovery. Each patient presented with atypical clinical symptoms, modest elevation of serum CK, and a slow response to treatment, which collectively posed diagnostic challenges during the initial assessment. CONCLUSIONS This report demonstrates that some patients with ER may have a prolonged disease course, atypical clinical symptoms, lack of clinically significant increase in CK levels, and slow treatment response. Therefore, misdiagnosis may occur in clinical practice, particularly in primary healthcare settings or among clinicians with limited experience. These findings may provide useful data and clinical insight for the diagnosis and management of ER.