Summary
A new inflammatory myopathy, called macrophagic myofasciitis, is being seen in increasing numbers. Since its appearance in 1993, more than 100 cases have been collected, mainly in France. The disease usually affects adults, with no sex predominance. Macrophagic myofasciitis generally becomes manifest as muscle pain (myalgias) of variable intensity, observed in 95% of the patients, usually associated with chronic debilitating fatigue (90%). Myalgias predominantly affect the limbs – notably the legs – and are often aggravated by exertion. Joint pain, primarily affecting the large peripheral articulations is noted in 50–60% of the patients and a moderate febrile syndrome in 30%. The are no cutaneous manifestations or digestive tract symptoms. The diagnosis is made based on histological examination of a surgical biopsy of the deltoid muscle including the fascia which shows the pathognomonic focal macrophage infiltrate. Complementary examinations are not always contributive: elevated muscle enzyme and creatine kinase levels are observed in 30%; a myopathic electromyogram tracing is obtained for less than 30%; gallium scinitigraphy suggests abnormalities but they are non-specific. A toxic origin (aluminated vaccines) is suspected and led to the initiation of an epidemiological inquiry conducted by the French Medications Agency. Numerous epidemiological, clinical, fundamental and therapeutic study protocols are in progress, in association with the Institute for Public Health Vigilance. *Authors: Prof P. Chérin, Dr J. Authier (August 2001)*.
