We disclosed the occurrences of myelitis with atopic diathesis preferentially affecting the cervical spinal cord in Japan. Recent nationwide survey revealed that this condition occurs throughout Japan. The characteristic features are: (1) young to middle-aged adults with atopic diathesis are affected, (2) stepwise progression and fluctuation of the symptoms are frequent, (3) paresthesia and dysesthesia are the initial and predominant symptoms while severe motor weakness is rare, (4) CSF abnormalities are infrequent and mild, (5) hyperIgEaemia and mite antigen-specific IgE are present in most cases and eosinophilia is present in about half cases, (6) cervical spinal cord is affected most frequently by clinical symptomatology and on MRI. In this condition, plasma exchange is beneficial in about 80% while corticosteroids are effective only in 50%. The spinal cord biopsy specimens demonstrated its neuropathology to be eosinophilic myelitis involving myelin as well as axon. We also found that Hirayama disease is associated with airway allergy such as allergic rhinitis and atopic asthma. In children, poliomyelitis-like illness after acute asthma attacks is well known as Hopkins syndrome. These findings strongly suggest a link between atopic diathesis and spinal cord damage.