[Neuromuscular diseases with eosinophilia]

Neuromuscular diseases with eosinophilia include a number of disorders associated with variable degrees of muscle, peripheral nerve, and connective tissue involvement. Eosinophilic infiltration in blood and/or tissue is a consistent finding. In addition to the neurologic manifestations of systemic vascularitis, in particular Churg and Strauss syndrome, there are three main forms of neuromuscular disease. Diffuse fasciitis or Shulman syndrome which can be limited to the fascia or associated with perimyositis is sensitive to corticosteroids. Eosinophilic myositis corresponds to focal muscle involvement and is also sensitive to corticosteroids. Eosinophilic polymyositis is a manifestation of essential hypereosinophilic syndrome and is life-threatening. Eosinophilia-myalgia syndrome and toxic oil syndrome are separate entities that occur in outbreaks and involve poisoning by ingestion of L-tryptophan and adulterated oil containing aniline respectively. The key to diagnosis of these neuromuscular diseases is muscle biopsy to detect the presence of polynuclear eosinophils.