Chronic neuropathy presenting as a floppy infant with respiratory distress.

Respiratory distress was the presenting feature in a 4-month-old male infant suffering from Déjérine-Sottas disease, an inherited sensory-motor polyneuropathy. This unusual but potentially benign disorder can be diagnosed upon peripheral nerve biopsy by noting extensive demyelination with "onion bulb" formation. Polyneuropathy should be considered in the differential diagnosis of infantile neuromuscular weakness including or solely involving bulbar and respiratory muscles.