Macrophagic myofasciitis

MMF was first described in 1998 by a consortium of French myopathologists as an emerging condition of unknown cause characterised by a defining lesion observed upon muscle biopsy. MMF was identified in patients affected by myalgia and fatigue. MMF was judged a consequence of a switch to intramuscular injection and the deltoid muscle being the preferred site of both vaccine injection and biopsy in France (while other sites were preferred for biopsy in other countries) and the commencement of HBV vaccination in French adults. Similar lesions could be detected in babies and children upon biopsy of the quadriceps as this is the site of vaccine administration in this group. MMF could also be experimentally reproduced in animals, with regression over time. It has been proposed that in a small portion of the population, vaccination results in persistence of aluminium-compound particles in macrophages in association with myalgia, fatigue, and cognitive dysfunction. A MMF disorder has been compared to autoimmune/inflammatory syndrome induced by adjuvants.[3][4] A case-controlled study in France found those with MMF were more likely to have received aluminium-containing vaccines. MMF was also associated with fatigue “and related functional limitations", with fatigue more common in the beginning of the malady that led to the biopsy. However, neither myalgia, arthralgia, nor any other symptoms or risk factors were identified as specific to those with MMF.[2]

Many of those with MMF had previously been treated for malaria with chloroquine or hydroxychloroquine.[5]

As of 2009, with few exceptions, MMF had only been reported in France.[1]