[Inflammatory myopathy following acute meningoccemia in a properdin-deficient patient: A case report]

Myalgia is a classical sign in invasive meningococcal diseases (IMD), but severe and persistent myalgia following an IMD have never been reported to date.

A 20-year-old man presented with purpura fulminans and meningitis caused by Neisseria meningitidis serogroup Y, revealing properdin deficiency. Although meningitis symptoms improved after antibiotherapy, initial myalgia of the lower limbs increased, associated with mild rhabdomyolysis. Magnetic resonance imaging (MRI) revealed an increased STIR (Short TI inversion recovery) signal of both quadriceps muscles, without abscess. After exclusion of other causes of myopathy, a post-infectious myositis was diagnosed. A four-week course of corticosteroids led to dramatic improvement.

Post-infectious inflammatory myopathy should be suspected in case of severe and persistent myalgia associated with rhabdomyolysis following an IMD, after exclusion of pyomyositis especially. A short course of corticosteroids seems to be effective.