Macrophagic myofasciitis: an infantile Italian case

Macrophagic myofasciitis is a recently identified inflammatory myopathy mostly described in adult French patients complaining of arthro-myalgias and fatigue. It is probably due to intramuscular injection of aluminium-containing vaccines and is characterized by a typical muscular infiltrate of large macrophages with aluminium inclusions. We report a 1-year-old Italian child presenting irritability, delayed motor development, hyperCKemia (up to 10 times the normal value), and typical features of macrophagic myofasciitis on muscle biopsy. The child recovered fully after steroid therapy. Macrophagic myofasciitis is a new treatable cause of motor retardation and hyperCKemia in children, and is probably more common than reported. Diagnosis requires a high index of suspicion and can be missed if biopsy is performed outside the vaccination site.