What Rhabdomyolysis Looks Like in Refeeding Syndrome?

“

TL;DR

This case report describes a 14-year-old girl with anorexia nervosa who developed rhabdomyolysis during refeeding syndrome, presenting with hip pain and elevated creatine kinase. Imaging (ultrasound and MRI) revealed focal myositis in multiple pelvic muscles, highlighting the importance of correlating clinical, laboratory, and imaging findings for early diagnosis. Delayed recognition of rhabdomyolysis in refeeding syndrome can lead to poor outcomes, emphasizing the need for vigilance in recovering anorexia patients.

Full summary

2,073 CHARS

**Background:** Rhabdomyolysis is a known but poorly documented complication of refeeding syndrome, particularly in patients recovering from anorexia nervosa. The clinical presentation can vary from mild to severe, and imaging findings are rarely described. This case highlights the imaging features of rhabdomyolysis in the context of refeeding syndrome, emphasizing the need for early recognition to prevent adverse outcomes.

**Methods:** This is a case report of a 14-year-old girl admitted to a psychiatric clinic for anorexia nervosa. After one month of successful treatment, she developed left hip pain that worsened with walking. Blood tests showed elevated creatine kinase (3650 UL; normal 30–135 UL), hypophosphatemia (1.3 mg/dL; 3–4.5 mg/dL), and hypomagnesemia (1.4 mg/dL; 1.7–2.2 mg/dL). Connective tissue disorders were excluded via negative myositis-specific antibodies. Ultrasound of the left hip revealed focal myositis, and pelvic magnetic resonance imaging (MRI) demonstrated involvement of the gluteus maximus, gemellus, and internal obturator muscles on the left side, with less involvement on the contralateral side.

**Key Results:** The patient's laboratory findings were consistent with refeeding syndrome (hypophosphatemia, hypomagnesemia) and rhabdomyolysis (elevated creatine kinase). Imaging confirmed bilateral but asymmetric myositis, predominantly on the left side. The case underscores that rhabdomyolysis can occur during refeeding in anorexia nervosa, and imaging (ultrasound and MRI) can help delineate the extent of muscle involvement.

**Clinical Implications:** Clinicians should be aware that rhabdomyolysis can present during refeeding syndrome in patients with anorexia nervosa, even after initial successful treatment. Early diagnosis through clinical history, laboratory tests (creatine kinase, phosphate, magnesium), and imaging (ultrasound, MRI) is crucial to guide management and prevent complications such as renal failure or compartment syndrome. Delayed diagnosis and inadequate management can lead to detrimental outcomes.