Weight Drop-Foot Drop: A Case Series of Peroneal Nerve Palsy from Leg Crossing after Tirzepatide-Mediated Weight Loss.

INTRODUCTION: Common peroneal nerve palsy, termed "slimmer's palsy," is a recognized complication of rapid weight loss. This case series describes 2 patients who developed foot drop following tirzepatide-induced weight loss precipitated by habitual leg crossing. CASE PRESENTATIONS: Peroneal neuropathy secondary to compression from habitual leg crossing developed in 2 male patients during tirzepatide therapy for weight loss. Patient 1 was a 55-year-old with severe hidradenitis suppurativa on multiple immunosuppressive medications who started on tirzepatide and lost 50 pounds over 5 months. Patient 2 was a 71-year-old with insulin resistance who lost 30 pounds over 3 months on tirzepatide. Both patients developed foot drop over 24-72 h. Treatment was behavioral modification to avoid leg crossing, supplemented by physical therapy, and, in patient 1, ankle bracing. Foot drop signs resolved over 3 to 4 months. CONCLUSION: Clinicians prescribing tirzepatide should counsel patients about peroneal nerve palsy risk during rapid weight loss. Patients should avoid prolonged leg crossing. Early recognition enables timely intervention and favorable outcomes.