Atopic myelitis: a clinical, biological, radiological and histopathological diagnosis

We describe a young patient with an unusual intramedullary lesion filled with eosinophils. The 21-year-old man developed chronic myelitis without optic neuritis or signs of systemic or infectious disease. A spinal biopsy was conducted because of the progressive extension and pseudo-tumoural aspect of the lesion. Histopathological analysis of the biopsy specimen revealed a severe inflammatory process with macrophages and numerous eosinophils. The eosinophil count in the blood and cerebrospinal fluid (CSF) were normal. Clinical, laboratory and radiological data did not correspond with the usual causes of eosinophilic myelitis. Abnormal Mite antigen-specific IgE levels and features similar to Japanese cases of atopic myelitis suggested an allergic origin. Despite normal total IgE levels, this case may be the second case of atopic myelitis reported in a Caucasian patient. Striking differences with the first reported case are the absence of a typical history of atopy and normal total IgE levels. This case highlights that atopic myelitis should be considered in myelopathy occurring in Caucasian patients even in the absence of hyperIgEaemia.