Atopy and neural damage.

The occurrence of myelitis with atopic diathesis (atopic myelitis) affecting young adults has recently been noted in Japan. The disease preferentially affects the posterior column of the cervical spinal cord, as shown clinically and by MRI. It is characterized by hyperIgEaemia and the presence of mite antigen-specific IgE. The spinal cord lesions have been shown to be eosinophilic inflammation on biopsy and thus an allergic mechanism is thought to be operative in this condition. In addition, we also found that Hirayama disease, juvenile muscular atrophy of the distal upper extremity, is also associated with airway allergy such as allergic rhinitis and atopic asthma. In children, poliomyelitislike illness after acute asthma attacks is well known as Hopkins syndrome. Moreover, by the prospective study of the history of allergic disorders in common neurologic diseases, an association between spinal progressive muscular atrophy (SPMA) and asthma as well as between myelitis and atopic dermatitis has been demonstrated. These observations strongly suggest a link between atopic diathesis and spinal cord damage. Central nervous system damage associated with atopic diathesis may be classified into two types; eosinophilic myelitis preferentially affecting the cervical spinal cord and lower motor neuron damage, such as Hopkins syndrome, Hirayama disease and SPMA. The former is typically associated with atopic dermatitis while the latter, with airway allergy.