In an infant, dermatitis due to hypersensitivity to "protein" substances is called eczema by most dermatologists, pediatricians and allergists, be they European or American. If the condition becomes chronic, in later childhood or adult life it may take many names, commonly, neurodermatitis, or it may still be called eczema by some physicians. If one limits the term eczema to an acute vesicular dermatitis, as some dermatologists do, the chronic condition that is seen in children and adults is certainly not eczema; but if one considers the etiology and evolution rather than the clinical appearance it is in some cases eczema. Confusion has arisen on account of these variations of nomenclature. While the clinical picture of eczema in infants is different from that of neurodermatitis in later childhood and in adult life, it seems to us, and we wish particularly to stress it, that the fundamental basis of atopic