Aluminum inclusion macrophagic myofasciitis: a recently identified condition

Macrophagic myofasciitis first was reported in 1998 and remained of unknown cause until 2001. The condition is characterized by a stereotyped and immunologically active lesion that is identified with a deltoid-muscle biopsy, which usually is performed in adult patients with diffuse myalgias and chronic fatigue. Electron microscopy, microanalytical studies, experimental procedures, and an epidemiologic study have demonstrated that the lesion is caused by the long-term persistence at the site of injection of aluminum hydroxide, an adjuvant used in vaccines against hepatitis B virus, hepatitis A virus, and tetanus toxoid. Persistent systemic immune activation that fails to switch off may represent the pathophysiologic basis of the chronic fatigue syndrome associated with macrophagic myofasciitis, similar to what happens in patients with postinfectious chronic fatigue and possibly idiopathic chronic fatigue syndrome.