Frequent detection of Mycoplasma pneumoniae in Bell's palsy.

The cause of Bell's palsy (BP) remains unknown despite various hints to an infectious etiology. Mycoplasma pneumoniae is a common pathogen of the respiratory tract causing pharyngitis, tracheobronchitis or pneumonia. Neurological complications are the most frequent extrapulmonary manifestation. So far, only a few case reports suggested an association between cranial nerve palsy and M. pneumoniae infection. Patients with a BP who were admitted to the Department of Otorhinolaryngology or Neurology of the University of Wuerzburg between 2000 and 2002 were tested serologically for the presence of antibodies against Borrelia burgdorferi, herpes viruses (HSV-1/2, VZV) and M. pneumoniae. The diagnosis of mycoplasmal infection was made when at least one of the following criteria was met: a threefold rise or more in the titer of antibody of M. pneumoniae in paired sample or a microparticle agglutination assay (MAG) of > or =1:40 and the detection of IgA and/or IgM antibodies in the acute phase serum. Ninety-one consecutive patients could be included. Fifteen patients showed a reactivation of a VZV ( n=12) or of a HSV-1 ( n=3) infection. In six cases the immunoblot revealed specific antibody bands for B. burgdorferi. In 24 patients (26.4%) a seroconversion of M. pneumoniae could be detected. Only two patients complained of mild respiratory symptoms. According to our results, M. pneumoniae is frequently associated with Bell's palsy. Thus, a routine screening for this pathogen, even in the absence of respiratory symptoms, is necessary.