Necrotising myositis after intravenous methylphenidat (Ritalin) injection

A 30 year old male intravenous drug user was admitted with a swollen painful left thigh after injection of 30 mg methylphenidat (Ritalin). On examination, we found a softball‐sized abscess in his left thigh. Striking lab results were a CK of 18 100 U/l, a CRP of 177 mg/l, and a WCC of 20.0×10⁹/l. A CT scan revealed a large abscess that contained multiple pockets of gas, extending from the lesser trochanter to the distal femoral condyle (fig 1). The patient went to theatre and the abscess was excised and drained and an extensive debridement was performed. Macro‐ and microscopic analysis showed acute necrotising myositis and extensive abscess formation. The patient was re‐examined 2 days later and the wound was closed. Thereafter, healing of the wound progressed well. The patient was discharged home 15 days postoperatively.

Figure 1 CT scans showing a large abscess.